Continental J. Fisheries Aquatic Sci - Vol 3

Continental J. Fisheries and Aquatic Science 3: 1 - 7, 2009 © Wilolud Online Journals, 2009. THE LENGTH - WEIGHT, LENGTH - LENGTH RELATIONSHIP AND CONDITION FACTOR OF Oreochromis niloticus IN GBEDIKERE LAKE, BASSA, KOGI STATE. Adeyemi, S.O, 1 Bankole, N.O2. and Adikwu, A.I1 Department of Biological Sciences, Benue State University, Makurdi. 2 National Institute For Freshwater, Fisheries And Research, New Bussa, Niger State. 1

ABSTRACT Length-weight, length-length relationships and condition factor of male, female and combined sex of Oreochromis niloticus in Gbedikere Lake, Bassa, Kogi State was studied. Seventy fish samples of total length ranging from 7.97cm to 19.50cm and weight between 20.8g and 309.4g collected between July and November 2008 were analyzed. Results showed that the male, females and combined sex had regression coefficient (b-value) of 2.76, 2.87, and 2.81 respectively. The males and females exhibited negative allometric growth. The length-length relationship had b-value of 1.18, -1.29, and -1.23 for males, females and combined sex respectively. Condition factor of the population varied from 1.53 to 5.62, females were in better condition than males. Condition factor between males and females was not significantly different (P>0.05). Gbedikere Lake is a good environment for growth, reproduction and survival of the Oreochromis niloticus. KEYWORDS: Length-length relationship, condition factor, Oreochromis niloticus, Bassa, Kogi State. INTRODUCTION Fish found in tropical and sub-tropical water system experience frequency growth fluctuations due to factors such as food composition changes, environment changes, rate of spawning to mentioned but a few, length weight, and length-length relationship can be used to assess the influence of these factors in fish. Kulbicki et al, (1993) and King (1966) reported that fish growth, mean weight of a given body length of fish estimation and the relative well being in fish can be known through this relationships length-weight, length-length relationships studies have been done in different water bodies and on different fishes. Notably among these are the report of King (1996) on some Nigerian fresh water fishes, Taiwo and Aransiola (2001) on Chrysichthys species in Asejire Lake, Fafioye and Oluajo (2005) on five fish species in Epe Lagoon, Nigeria and Laleye (2006) on Oreochromis niloticus in Oeume River in Benin. Oreochromis niloticus is a fast growing and highly prolific species, though an indigenous Africa fish. It is also an inter-continental traveler (Bardach, et.al., 1972). It has high tolerance to environmental conditions and its ability to accept compounded and natural feeds makes it economically cultivable and viable. It is characterized by the caudal fin with elongated body and a number of narrow bands on the back. The study present information on the length-weight, length-length relationships and the condition factor of this valuable fish species is in order to aid the management of the lake. MATERIALS AND METHODS STUDY AREA Lake Gbedikere is a natural lake located between Latitudes 30240 and Longitudes 5014E and is about 10km to the East of Oguma the Head quarter of Bassa Local Government Area of Kogi State. Water enters the Lake from tributaries that run from River Benue during rainy or flood season. When the season is over, the Lake separates out. The Lake is about 450m north of Gbedikere village. The water body covers about 400 – 450m and a depth of 10 – 14m deep, depending on the season. The lake is used for fishing and other Domestic activities; consequently most of the settlers around the Lake are fishermen (Upper Benue River Basin Development Authority, 1985). The lake experience two seasonal periods; the rainy season starts in the month of May and last till October and is characterized by heavy down pour which

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sometimes have an extensive flood action. The dry season is from late October to April and is characterized by cold, dusty -dry wind followed by intense heat. The lake contains fish, other aquatic animals and some macrophytes such as wire grass (Cyperus articulatus) which are used for waving mats. SAMPLES COLLECTION Fish samples were identified and collected from the fishermen catches using gill nets, cast nets, hooks and lines and Malian traps between June and November 2008. Total length (cm) and weight (g) were taken using measuring board and top loading balance. Length-weight relationship was calculated using the formula: W=aLb which was transformed to logarithm of the form Log W=Log a + b log L Using instat statistics package Where W= body weight of the fish (g), L=total body length of fish (cm) a and b=values estimated by regression formula. The condition factor (K) was calculated using the K=100w (Pauly, 1984) L3 Where K= condition factor, L=Total body length of fish (cm) W=body weight of fish (g). RESULTS AND DISCUSSION A total of seventy species of Oreochromis niloticus were collected for the study. The length-weight frequency distribution of the fish species in Gbedikere Lake shown in Table 1.The standard length (cm) and their corresponding weights (g) are: Males 8.4cm – 19.5cm/23.5g – 309.4g, females 7.9cm – 18.6cm/20.8g – 208.5g, combined sex 7.9cm – 19.5cm/20.8g – 309.4g respectively. Table 1: Length and weight frequency distribution of Oreochromis niloticus in Gbedikere Lake, Bassa, Kogi State. Sex Standard Length (cm) Body Weight (g) n

Min

Max

Mean + S.D

Min

Max

Mean + S.D

Males

35

8.40

19.50

14.01+3.11

23.5

309.4

109.97+2.81

Females

35

7.90

18.60

13.23+3.01

20.8

304.5

97.15+62.75

Combined sex

70

7.90

19.50

13.62+3.01

20.8

309.4

103.56+67.78

n=Number, Min=Minimum, Max=Maximum, SD = Standard Deviation. The male length-weight relationship is expressed by the regression equation: Log W=0.066 + 2.758 Log L (r = 0.9529) Fig 1. The female length-weight relationship is expressed by the regression equation: Log W=0.511 + 2.8669 Log L (r = 0.9609) Fig 2.

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The combined sex’s length-weight relationship is expressed by the regression equation: Log W=0.587 + 2.8078 Log L (r = 0.9574) Fig 3. Log length – log weight of males is expressed by the regression equation Log W = 2.758 – 1.1801 Log L (r = 0.9529) Fig 4. Log length – log weight of females is expressed by the regression equation Log W =2.8669 – 1.2914 Log L (r = 0.9609) Fig 5. Log length – log weight of combined sexes is expressed by regression equation Log W = 2.8078 – 1.2313 Log L (r = 0.9574) Fig 6. The length-length relationship also had a regression coefficient (b. values) of 1.1801, -1.2914 and -1.2313 for males, females and combined sexes respectively. Table 2: Length-length relationship of Oreochromis niloticus in Gbedikere, Lake Bassa, Kogi State. Sex Total length (cm) Min

Max

Mean +S.D

n

a

b

r

Males

11.2

24.3

17.75+3.04

35

2.758

1.1801

0.9529

Females

11.0

23.9

17.45+2.99

35

2.8669

-1.2914

0.9609

Combined sex

11.0

24.3

17.65+2.12

70

2.8078

-1.2313

0.9574

SD = Standard deviation, n=Number, a=Intercept, b=Slope, r=Coefficient of determination. The condition factor (CF) ranged between 1.59 - 5.24, 2.14 – 5.62, and 5.62 for males, females and combined sexes (Table 3). Table 3: Condition factor of Oreochromis niloticus in Gbedikere Lake Bassa, Kogi State. Sex Minimum Maximum Condition factor (k) (Mean + SD) Males 1.59 5.24 3.58+0.68 Females 2.14 5.62 3.71+0.74 Combined sex 1.59 5.62 3.64+0.71 The b-values of 2.76, 2.87 and 2.81 indicate that males and females showed negative allometric growth, based on Begenal and Tesch (1978) criteria of 3. Similarly Pauly (1984) did report that a slope value greater than 3 denotes positive allometric growth that was not similar to the findings Anibeze (1995). This indicates that Oreochromis niloticus did not obeyed the cube law of growth (Le Cren, 1951) which is not commonly obeyed by most fishes. Etim (2000) and Fafioye and Oluajo (2005) respectively reported 2.951 and 3.042 b-value Chrysicthys nigradigitatus combined sex which are similar to the findings of the study. The value recorded during this study were similar with 1.53 to 2.55 reported by Ekanem (2006) for Chrysicthys nigradigitatus (Laceped) from Cross River and also higher than 0.79+0.15 which is less than 1.0 as reported by Fafioye and Oluajo (2006) from Epe Lagoon, this could be due to difference in the condition of the habitat such as Physico-Chemical parameters, plants and animal communities. Females have better condition factor than the males during the period of this study. CONCLUSION AND RECOMMENDATIONS The composition of both sexes gave a better overview of length-weight relationship and condition factor of Oreochromis niloticus. The result of this study show negative allometric growth pattern, the b-values were generally in agreement with results for fishes of the same genus obtained from other geographical areas. Confirming that Gbedikere Lake in Bassa, Kogi State is a good environment for the growth, reproduction and survival of the species. The study provides basic information on the length-weight, length-length relationship and condition factor of Oreochromis niloticus that will be useful for fishery biologist and managers in Nigeria.

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The in-depth studies on the length-weight, length-length relationship and condition factors; and other aspect of biology and biodiversity of Oreochromis niloticus towards sustainable management in Gbedikere Lake Bassa, Kogi State should be further elucidated.

Standard length (cm) Fig 2 Length-weight relationship of female Oreochromis niloticus IN GBEDIKERE LAKE, 4 BASSA, KOGI STATE

Adeyemi, S.O et al: Continental J. Fisheries and Aquatic Science 3: 1 - 7, 2009

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REFERENCES Anibeze, C.I.P. (1995). Aspect of ecobiology of Heterobranchus longifilis (Valenciennces, 1840) in Idodo River Basin (Nigeria) and their application of aquaculture. University of Nigeria, Nsukka. 153p Ph.D. Thesis. Bagenal, T.B. and F.W. Tesch (1978). Age Growth in Method of Assessment of Fish Production in Fresh Waters, (ed. T. Bagenal). Oxford Blackwell Scientific Publication. pp 101-136. Bardach, J.E., Ryther, J.H and McLarney, W.O. (1972). Aquaculture: the farming and husbandry freshwater and marine organism. Wiley-Inter-Science. New York. Ekanem, S.B. (2006). Some Reproductive Aspect of Chrysichthys nigrodigitatus (Lacepede) from Cross River, Nigeria. Fishbyte (ed. G. Silverstre. Fisheries Section of the Network of Tropical Aquaculture and Fisheries Professionals (NTAFP). NAGA ICLARM Quarterly. 23(2):24-28. Etim, L. (2000). Length-Weight Relationship of Eight Fish species from the Cross River, Nigeria. Global Journal of Pure and Applied Sciences. 6 (4): 571-575. Fafioye, O.O and O.A. Oluajo (2005). Length-Weight Relationship of five Fish Species in Epe Lagoon, Nigeria. African Journal of Biotechnology. 4(7): 749-751. King, R.P. (1996). Length-weight relationship of Nigerian freshwater fishes. NAGA: The ICLARM Quarterly 19(3): 49 – 52. Kulbicki, M., Moutham, G., Thollot, P. and Wanteiz, L; (1993). Length-weight relationship of fish from the lagoon of Mew Caledonia. NAGA ICLARM Quarterly 16 (2-3):26 -30. Laleye, P.A. (2006). Length-Weight and Length-Length relationship of fishes from the Oueme River in Benin (West Africa). Journal of Applied Ichthyology 22:330-333. Le Cren, E.D. (1951). The Length-Weight Relationship and Seasonal Cycle In: Gonad Weight and Condition in the Perch, Perca fluviatillis. Journal of Animal Ecology. 20:201-219. Pauly, D. (1984). Fish Population Dynamics in Tropical Waters: a manual for use with Programmable calculators. ICLARM Studies and Revision. 8: 325pp. Taiwo, I.O., and Aransiola, M.O. (2001). Length-weight relationship, condition factors and fecundity of Chrysichthys nigrodigitatus and Chrysichthys walkeri in Asejire Lake. Proceeding of the 16th Annual Conference of the Fisheries Society of Nigeria (Maiduguri, 2001), pp.277-281. Upper Benue River Basin Development Authority, (1985): Feasibility study of Lake Geriyo by Upper Benue River Basin Development Authority. Authority Information Manual. Received for Publication: 17/03/2009 Accepted for Publication: 14/05/2009 Corresponding Author (Present Address) Adeyemi, S.O Department of Biological Sciences, Kogi State University, Anyigba. Email: [email protected]

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Continental J. Fisheries and Aquatic Science 3: 8 - 11, 2009 © Wilolud Online Journals, 2009. THE LENGTH-WEIGHT RELATIONSHIP AND CONDITION FACTOR OF Protopterus annectens (OWEN) IN GBEDIKERE LAKE, BASSA, KOGI STATE, NIGERIA. 1

Adeyemi, S.O1, Bankole, N.O2 and Adikwu, I.A.1 Department of Biological Sciences, Benue State University, Makurdi. 2Institute of Fresh Water Fisheries and Research, New Bussa, Niger State. ABSTRACT A total of sixty two samples of Protopterus annectens (Owen) were examined for this study from Gbedikere Lake in Bassa Local Area of Kogi State between August and November 2008. The length-weight relationship calculated for species gave a b-value of 2.55 which is indicative of negative allometric growth. It attained a length of 59cm and weight of 397g. The condition factor varied from 0.23 to 0.76 with a mean of 0.39+0.08 and shows that the fish is well and in good environment for growth and survival. KEYWORDS: Protopterus annectens, allometric growth and survival.

INTRODUCTION Fish found in tropical and sub-tropical water system experience frequency growth fluctuations due to factors such as food composition changes, environment changes, rate of spawning to mention but a few, length weight relationship can be used to assess the influence of these factors in fish. Kulbicki et al, (1993) and King (1966) reported that fish growth, mean weight of a given body length of fish estimation and the relative well being in fish can be known through this relationships length-weight relationships studies have been done in different water bodies and on different fishes. Notably among these are the report of King (1996) on some Nigerian fresh water fishes, Taiwo and Aransiola (2001) on Chrysichthys species in Asejire Lake, Fafioye and Oluajo (2005) on five fish species in Epe Lagoon, Nigeria and Laleye (2006) on Oreochromis niloticus in Oeume River in Benin. Protopterus annectens commonly known as African lungfish is the only species of primitive family Lepidosirenidae found in West African fresh waters (Reed et al, 1976). Holden and Reed (1972) reported that the ancient fish did not form any significant part of commercial catches and that the flesh is tasty but many traditional taboos prevent the eating of the species. The study present information on the length-weight relationships and the condition factor of this valuable fish species is in order to aid the management in the lake. MATERIALS AND METHODS STUDY AREA Lake Gbedikere is a natural lake located between Latitudes 30240 and Longitudes 5014E and is about 10km to the East of Oguma the Head quarter of Bassa Local Government Area of Kogi State. Water enters the Lake from tributaries that run from River Benue during rainy or flood season. When the season is over, the Lake separates out. The Lake is about 450m north of Gbedikere village. The water body covers about 400 – 450m and a depth of 10 – 14m deep, depending on the season. The lake used for fishing; consequently most of the settlers around the Lake are fishermen (Upper Benue River Basin Development Authority, 1985). The lake experience two seasonal periods; the rainy season starts in the month of May and last till October and is characterized by heavy down pour which sometimes have an extensive flood action. The dry season is from late October to April and is characterized by cold, dusty -dry wind followed by intense heat. The Lake contains fish, other aquatic animals and some macrophytes such as wire grass (Cyperus articulatus) which are used for weaving mats.

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Adeyemi, S.O et al: Continental J. Fisheries and Aquatic Science 3: 8 - 11, 2009

SAMPLES COLLECTION Fish samples were identified and collected from the fishermen catches using gill nets and Malian traps between August and November 2008. Total length (cm) and weight (g) were taken using measuring board and top loading balance. Length-weight relationship was calculated using the formula: W=aLb which was transformed to logarithm of the form Log W=Log a + b log L Using instat statistics package Where W= body weight of the fish (g), L=total body length of fish (cm) a and b=values estimated by regression formula. The condition factor (K) was calculated using the K=100w (Pauly, 1984) L3 Where K= condition factor, L=Total body length of fish (cm) W=body weight of fish (g). RESULT AND DISCUSSION A total of sixty two species of Protopterus annectens were collected for the study. The total length ranged between 22.30cm and 59.2cm with a mean of 34.27+ 6.33 and weigh between 19.70g and 397.9g with a corresponding mean of 158.0+78.97 (Table 1). This shows that the specie used for the study were relatively matured. Table 1: Summary of length and weight distribution of Protopterus annectens in Gbedikere Lake, Bassa Local Government Area, Kogi State. Total Length (cm) Body weight (g) Species N Min Max Mean+S.D Min Max Mean+S.D Protopterus annectens 62 22.30 59.20 34.27+6.33 19.70 397.90 158.00+78.97 Condition factor (CF), parameter of a, b and r of the length weight relationship of Protopterus annectens is shown in Table 2 and Fig 1. Table 2: Condition factor (CF) of Protopterus annectens in Gbedikere, Lake, Bassa Local Government Area, Kogi State. Parameters Values A 0.0183 B 2.552 R 0.9229 Mean condition factor (CF) 0.39+0.08 a, b = regression coefficient; r = correlation coefficient The exponent of (b) value of 2.553 shows that Protopterus annectens exhibits negative allometric growth this indicate that growth in length increase as weight increases and also the rate of increase in body length is not proportional to the increase in body weight. This result is different from the one obtained by Oniye et al (2006) when he obtained the b-value for male and female P. annectens in Jachi Dam near Katsina in Katsina State, Nigeria to be 3.12 and 3.22 respectively. This could be due to the condition of the fish caught during different season, location, sex, sample site and nature of the water body. The regression coefficient of 0.9229 compares favourable with the 0.86 and 0.84 obtained by Oniye et al, (2006) for P. annectens male and female respectively which suggest

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that the findings of this study is valid. Fafioye and Oluajo (2005) also obtained a condition factor of 1.00 for some other fish specie from Epe Lagoon. CONCLUSION AND RECOMMENDATIONS The composition of both sexes gave a better overview of length-weight relationship and condition factor of Protopterus Annectens. The result of this study show negative allometric growth pattern, the b-values were generally in agreement with results for fishes of the same genus obtained from other geographical areas. Confirming that Gbedikere Lake in Bassa, Kogi State is a good environment for the growth, reproduction and survival of the species. The study provides basic information on the length-weight, length-length relationship and condition factor of Protopterus Annectens that will be useful for fishery biologist and managers in Nigeria. The in-depth studies on the length-weight, length-length relationship and condition factors; and other aspect of biology and biodiversity of Protopterus Annectens towards sustainable management in Gbedikere Lake Bassa, Kogi State should be further elucidated.

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Adeyemi, S.O et al: Continental J. Fisheries and Aquatic Science 3: 8 - 11, 2009

REFERENCES Fafioye, O.O and O.A. Oluajo (2005). Length-Weight Relationship of five Fish Species in Epe Lagoon, Nigeria. African Journal of Biotechnology. 4(7): 749-751. Holden, M. and W. Reed (1972). West African Fresh Water Fishes West African Nature Book Longman Publications, London. 68p. King, R.P. (1996). Length-weight relationship of Nigerian freshwater fishes. NAGA: The ICLARM Quarterly 19(3): 49 – 52. Kulbicki, M., Moutham, G., Thollot, P. and Wanteiz, L; (1993). Length-weight relationship of fish from the lagoon of Mew Caledonia. NAGA ICLARM Quarterly 16 (2-3):26 -30. Laleye, P.A. (2006). Length-Weight and Length-Length relationship of fishes from the Queme River in Benin (West Africa). Journal of Applied Ichthyology 22:330-333. Pauly, D. (1984). Fish Population Dynamics in Tropical Waters: a manual for use with Programmable calculators. ICLARM Studies and Revision. 8: 325pp. Oniye, J.S., Adebote, D.E., Usman, S.K and Makpo, J.K. (2006). Some aspects of Biology of Protopterus annectens in Jachi Dam near Katsina, Katsina State Nigeria. J. Fish. Aquat. Sci., 1(2): 136 – 141, 2006. Reed, W., J. Burchard, A.J. Hopson, J. Jennes, I. Yaro (1967). Fish and Fisheries of Northern Nigeria. 1st Ed. Ministry of Agriculture, Northern Nigeria. 226p. Taiwo, I.O., and Aransiola, M.O. (2001). Length-weight relationship, condition factors and fecundity of Chrysichthys nigrodigitatus and Chrysichthys walkeri in Asejire Lake. Proceeding of the 16th Annual Conference of the Fisheries Society of Nigeria (Maiduguri, 2001), pp.277-281. Upper Benue River Basin Development Authority, (1985): Feasibility study of Lake Geriyo by Upper Benue River Basin Development Authority. Authority Information Manual. Received for Publication: 17/03/2009 Accepted for Publication: 13/05/2009 Corresponding Author (Present Address) Adeyemi, S.O Department of Biological Sciences, Kogi State University, Anyigba. Email: [email protected]

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Continental J. Fisheries and Aquatic Science 3: 12 - 19, 2009 © Wilolud Online Journals, 2009. SOCIO-ECONOMIC FACTORS INFLUENCING THE ADOPTION OF “GURA” FISH TRAP TECHNOLOGY IN NIGERIA Sule, A.M1 ; Sanni, A.O1 ;Olowosegun, T1; Agbelege, O. O2 and Olabanji, M. U1 National Institute for Freshwater Fisheries Research, P.M.B. 6006, New Bussa, Niger State, Nigeria. 2 Federal College of Freshwater Fisheries Technology, Alau , Maiduguri, P. M.B 1060, Maiduguri, Borno State, Nigeria. ABSTRACT: The basic premise of extension that agricultural technology will diffuse from more progressive farmers to others in the rural communities is refutable. What is conspicuous in adoption and diffusion of most fishing technologies are basically cost and appropriateness for a large segment of the clientele. A total of one hundred respondents were interviewed using questionnaire in both Lakes Chad and Kainji. Descriptive statistics of mean, percentages and ordered ranking were used to analyse the socio-economic characteristics of the fishers, while ttest was used in determining the significant differences in the socio-economic variables of the two set of respondents. Analysis of result showed that the means of ages for the two sets of respondents were 39 and 33 years, number of years spent on education was 2.8 and 2.3 years, income of N44, 220 and N27, 260 and number of traps as 58.3 and 26.9. The t-test result showed significant differences in the fishers’ age, household size, income and the number of traps owned by the two sets of respondents (P<0.05). Perception indices for the “gura” trap technology attributes were found to be high 0.89 and 0.91 respectively indicating that the fishers considered all the attributes of the “gura” technology as very important. Recommendations in the form of regular monitoring and enforcement of appropriate mesh sizes, identifying and considering the indigenous knowledge systems in technology formulation as well as conducting environmental impact assessment on the use the fishing trap were proffered for rational and sustainable use of the technology for fisheries development. KEY WORDS: Socio-economic, Influencing, Adoption, Gura, Technology, Nigeria INTRODUCTION Adoption is defined as the actual use of a technology on a continuous and large-scale basis. The rate of adoption of improved fishery technologies by fisherfolks is very low. The question is, how appropriate are the technologies developed at the research institutes? Why is low or no adoption not given a critical thought? Indeed change in agricultural technology is one of the accelerators of its development. Improved technologies are usually released with recommendations in addition to their high cost. The high cost and investment required are some of the impediments for adoption of most of the improved technologies. When developing technologies there is need for a development strategy that takes into cognizance, the socio-economic factors as they apply to the situations of the clientele. The socio-economic factors related to the adoption of new technologies which include personal characteristics of the fisherfolks and the characteristics of the context in which they act are therefore imperatives. This paper discusses the highlights of the “Gura” trap or “Guran Mali” fishing technology. “Gura” trap or Malian trap was introduced to the Nigerian fishermen by the Malian immigrant fishermen around 1980s, (Sarch and Madakaru, 1995). The trap gained wide acceptance (adoption) in many freshwater bodies in the Northern part of Nigeria. The traps are mostly used during the rising and receding floods. At the peak of the flood, it is usually difficult for the fishermen to operate them though; very few fishermen do (Agbelege et al 2001). Malian traps catch all types of fish species but mostly Clarias and Tilapia (Agbelege, et al. 2003). Generally, the effectiveness of the technology in trapping the target fish species resulted in impressive adoption and diffusion rate of the “Gura” trap, hence the desire for the study to probe deeper and understand the rationale behind

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the fast dissemination of the technology. Nonetheless, the problem of effectively harnessing new technologies to meet the needs of rural development is a highly complex one that requires careful management given the two themes of development. One is to increase fish production to meet the needs of the teeming population and the other is the conscious desire to prevent the degradation of the natural resources caused by bad fishing practices. The objectives of this study are to give in sights into the adoption behaviour of the fisherfolk with emphasis on socio-economic factors; technology attributes and perception of the fishers on the attributes of the technology as they influence its adoption. It was hypothesized that there were no significant differences between the socio-economic characteristics of the fishers in Lakes Chad and Kainji.

METHODOLOGY The study areas: Lake Chad lies between latitude 120 N 140 20’ N and longitude 130 150 30’ E south of Sahara within the sahel zone of West Central Africa. It is a very large shallow eutrophic natural lake shared by four West African Countries, Chad 50%, Nigeria 25%, Niger 17% and Cameroun 8%. The shoreline of the Nigerian portion of the lake is characterized by numerous islands that extend for about 256km from the north of River Yobe at Malanfatori in the north to the mouth of El-Beid at Wulgo in the south. The surface area of the lake is not constant as it has been fluctuating between 6000km2 (Bukar and Gubio, 1985) and LCBC, 1989). On the other hand, Lake Kainji was formed as a result of the impoundment of River Niger by the construction of Kainji Dam. The impoundment led to the creation of the largest man-made lake in Nigeria in 1968. The lake is located between longitudes 40 20’ North and 40 45’ East; and latitudes 90 50’ and 100 55’ North. The lake is 136km long, 24km wide at its widest point with an area of 1,250 square kilometers. Though the primary purpose of constructing the dam is the generation of hydroelectric power, the creation of the lake offered opportunities for a variety of development projects such as fisheries, irrigated agriculture and improved navigation from the coast up to the Republic of Niger (KLI, 1977). The study was conducted in two locations, Lakes Chad and Kainji. The research design for the study was survey and employed the cross-sectional method while the research instrument was questionnaire. The administration of the questionnaire was in two phases, which were during the rising and receding floods in the months of October and May, 2007 respectively. A two stage random sampling technique was used in this study to get the required number of the respondents in Lakes Chad and Kainji. The first stage involved the selection of five fishing villages in each of the lake areas. The second involved random selection of ten respondents from each of the selected villages in the two lake areas. In all,

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50 respondents were selected as sample size for each Lake area making a total of 100 respondents (Table 1).dministration of the instrument was in two phases, during the rising and receding floods in October and May, 2007. Descriptive statistics of frequency counts, percentage, mean and ranking were used for analysis. Student’s t-test was also used to compare the socio-economic variables of the respondents. To measure the fisher folks’ perception of the technology attributes, they were asked to indicate their degree of perception on seven technology attributes on a 2point scale in accordance with Ajayi (1998) and Anyanwu (2002). The response categories and their weighted scores were as follows: Important = 1; not important = 0. The mean ( X ) perception score for each of the 7 attributes was computed by dividing the total perception score by the total number of respondents (50) for each lake area. The mean ( X ) technology attribute perception score was dichotomized as 0.0 - 0.49 = not important and 0.5 1.0 = important. The technology attribute perception index of the fisher folks was calculated by dividing the grand mean ( X ) perception score by the total number of technology attributes (7). RESULTS AND DISCUSSION Table 1 shows a total sample size of one hundred respondents from ten fishing communities in the two lake areas. Five communities were selected with ten respondents each making a total of fifty for Lake Chad and same for Lake Kainji. Table 1: Names of Villages and number of respondents sampled Lake Chad Number of Lake Kainji respondents Daban Shata 10 T. A. Danbaba Dumba 10 T. A. Angulu Lagos 10 Shagunu Maiyashi Abuja 10 Wara Madayi 10 Garafini

Number respondents 10 10 10

of

10 10

Table 2 presents data on the socio-economic characteristics of the fisher folks in the two lake areas. Entries in the table indicated that while (40%) of the respondents in Lake Chad were between the age range of 34-41 years, much younger fishers (26-33 years) were the majority (54%) in Lake Kainji. However, the mean ages of the respondents in the two Lake areas were 39 and 33 years respectively. Nonetheless, the ages of the respondents in the two lake areas are in the innovative category of adopters and are in their economically active years as confirmed by the conventional studies of Roger (1995); Adeoti and Ibitoye (2002) and Fanikayode and Oloruntoba (2002), where younger people are regarded as more innovative, responsive and adaptive to change than the older people who prefer to stick to traditional practices for risk aversion. Educationally, the mean numbers of years spent by the respondents in the study areas were 2.8 and 2.3 years respectively. Though, there exists disparity in the mean years spent on education in the two study locations, there was a general low literacy level among the two sets of respondents as a larger chunk of 68-70% were not educated. The implication of this is that for any technology to be successfully transferred and adopted the technology itself has to be self appealing in its attributes or more effort has to be put on awareness creation and persuasion in order to generate the needed interest for its adoption. Data on household size indicated large mean household sizes for both sets of respondents. While the mean household size for a respondent in Lake Chad was 9.6 that of Lake Kainji were 7.4. These values are considered large and a welcome advantage for the fishers as more hands would be available for easing the labour involved in the use of the technology for fish production in the lakes. The mean monthly income level of the respondents in lakes Chad and Kainji were N44, 220 and N 27, 260 respectively. This means that by virtue of their income from

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Sule, A.M et al: Continental J. Fisheries and Aquatic Science 3: 12 - 19, 2009

the use of the fish traps, the Lake Chad fishers are much more financially buoyant than their counter parts in Lake Kainji. This is probably due to the difference in the scale of fishing activities using the traps, differences in the size of the traps and amount of traps owned favoured the Lake Chad fishers. The mean numbers of traps at the disposal of the fishers from the two lake areas are 58.3 for Lake Chad fishers and 26.9 for Lake Kainji fishers. This observed difference in the number of traps could in turn be explained by amount of money available with each of the fisher folks for the procurement of the technology. Table 2: Socio- economic characteristics of the respondents in Lakes Chad and kainji. Socio-economic characteristics Age (yrs) 18-25

Lake Chad

Lake Kainji

Freq. 3

% 6

Lake 6

Kainji 12

6 20 18 3 50

12 40 36 6 100

27 11 4 2 50

54 22 8 4 100

5 4

10 8

3 7

6 14

Quranic None Total Household size 1-5 6-10

7 34 50

14 68 100

5 35 50

10 70 100

7 24

14 48

10 32

20 64

11-15 16-20 21-25 Total Income (N000) 10-30

14 3 2 50

28 6 4 100

7 0 1 50

14 0 2 100

18

36

37

74

31-50 51-70 71-90 > - 90 Total No. of owned 10-30

18 8 4 2 50

36 16 8 4 100

12 1 50

24 2 100

15

30

43

86

15 9 5 6 50

30 18 10 12 100

7 50

14 100

26-33 34-41 42-49 50-57 Total Education Tertiary Secondary Primary

31-50 51-70 71-90 > - 90 Total

( X ) Age L. Chad = 39 years L. Kainji = 35 yrs

( X ) No. of yrs in education L. Chad = 2.80 L. Kainji = 2.30

( X ) HHS L. Chad = 9.6 L. Kainji = 7.4

( X ) = income L. Chad = N44,220.00 L. Kainji = N27,260.00

traps

15

( X ) No of traps owned L. Chad = 58.3 L. Kainji = 36.9

Sule, A.M et al: Continental J. Fisheries and Aquatic Science 3: 12 - 19, 2009

The result of the t-test analysis of the socio-economic characteristics of the respondents presented in table 3 showed that there exists significant differences (P<0.05) in the fishers age, household size, income and the number of traps owned by the respondents in the two Lake Areas. However, the result showed that there was no significant difference in the level of education of the two set of fishers in Lakes Chad and Kainji. It could therefore be seen that fishers’ age, household size, income and the number of traps owned are important factors which influenced the respondents’ perception of the attributes of the technology in the two lake areas. Table 3: T-test result of the socio-economic characteristics of the respondents in Lakes Chad and Kainji. Socio-economic Variables Lake Chad Lake Kainji Decision Age: Mean values 39.34 t-stat 3.91 33.0 Reject Ho t-critical (2 tail) 2.00 Education Mean values 2.78 t-stat 0.51 2.34 Accept Ho t-critical 2.00 Household size Mean values 9.62 t-stat 2.50 7.94 Reject Ho t-critical 2.01 Income Mean values 44.2 t-stat 5.51 27.3 Reject Ho t-critical 2.01 No of traps owned Mean values 58.3 t-stat 5.86 26.9 Reject Ho t-critical 2.009 Ho = null hypothesis, Degree of freedom = 49, P<0.05. The sources of information on “gura” technology was sought from the fishermen in both lakes and classified into personal and impersonal information sources as shown in table 4. The primary goals of the various sources are to create awareness by diffusing among potential adopters on useful and practical information and encourage its application. Personal channels involved a one-to-one interaction between sender and receiver and it enables the sender to tailor the message more appropriately and react to the receiver through a feedback mechanism (Katz, et al, 1963). Thus, they tend to be more effective than impersonal channels in transmitting information on technology among the resource poor and illiterate clientele. The result of the study on Table 4 showed that the personal information source (Fellow Fishermen/neighbours) was the only information source responsible for the “gura’ technology adoption. Hence, 100% of the respondents obtained their information from fellow fishermen/neighbours. The implication is that the technology did not emanate from the research institutes. It was based on indigenous knowledge system and therefore enjoyed no formal extension dissemination strategies.

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Sule, A.M et al: Continental J. Fisheries and Aquatic Science 3: 12 - 19, 2009

Table 4: Sources of information Sources of Information Extension workers Fellow fishermen/neighbours Radio farm programmes News letter Research bulletins Television farm programmes Total

Percentage Lake Chad 100 100

Lake Kainji 100 100

Table 5 showed the mean ratings and rankings of the seven attributes of the “gura” trap fishing technology by the respondents in Lakes Chad and Kainji. Analysis of these attributes showed that in Lake Chad the fishers considered the technology to be cheap and affordable ( X ) = 1.0) with minimum price of N500 and maximum of N1000 per unit as the most important attribute. The trap being readily available and ease of operation were considered as second most important attributes of the technology. ( X ) = 0.96). However, the attribute that the catches attract better price was the least important attribute ( X ) = 0.70) of the technology for the Lake Chad respondents. On the other hand, fishers in Lake Kainji considered the ease of operation of the technology and its compatibility with the existing practice as the most important attribute ( X ) = 1.0) of the technology. The perception of the attribute of the technology that it is cheap and affordable was the least important attribute to Kainji Lake respondents. The implications of these results are that what the Lake Chad fishers considered as cheap and affordable might not be seen that way by the Kainji Lake Fishers. This might probably be due to the fact that the Lake Chad fishers are wealthier than their Lake Kainji counterparts. Secondly, Kainji Lake fishers tended to prefer a technology that is compatible with the existing practice and easy to operate. Analysis also showed that the mean ratings of the perception scores for the two sets of respondents in the two Lake areas ranges from a minimum of 0.70 to 1.0 which showed that all the ‘gura’ trap fishing technology attributes are considered important by the fisher folks. Similarly, the perception index of 0.89 and 0.91 for lakes Chad and Kainji equally showed that all the technology attributes are perceived very important by the respondents in the study areas. The overwhelming importance of the attributes of “gura” trap fishing technology and its acceptance by the fishers in both lake areas stemmed from the fact that many technologies designed for agriculture are basically inappropriate for a large segment of the clientele, and therefore the solution lies in the design of appropriate technology (Morrison et al, 1984). Hence, if technology which is appropriate for the resource poor farmer can be designed, adoption and diffusion can proceed from that type of farmer to the aggregate rather than the other way round (Rogers, 1983). Therefore, small farmers will adopt appropriate technology, if it is economically and technically superior for their farming or fishing systems, just as rapidly as the larger, so called “progressive” farmers (Luning, 1982). Thus, ‘gura’ fishing trap technology tends to satisfy the above conditions of appropriate technology and thence its adoption and diffusion is self propagating. This finding confirmed with consistency what was discovered in a previous study by Sule et al. (1994) that for a fishery innovation to be adopted, the equipment has to be cheap or loans have to be made available to facilitate adoption; the catches have to look attractive; the operation has to be simple, and maintenance facilities have to be made available while the technique should be compatible with already existing practices.

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Sule, A.M et al: Continental J. Fisheries and Aquatic Science 3: 12 - 19, 2009

Table 5: Fisher folk’s perception of the attributes of the “gura’ trap fishing technology. S/No Technology Attributes Lake Chad Lake Kainji Mean rating Rank Mean rating 1 Cheap and affordable 1.0 1st 0.74 2 Readily available 0.96 2nd 0.90 3 Compatibility with existing practice 0.94 4th 1.0 4 Catches very well 0.86 5th 0.94 5 Catches attracts better price 0.80 6th 0.88 6 Catches are hauled live 0.70 7th 0.92 7 Ease of operation 0.96 2nd 1.0 Total mean scores 6.22 6.38 Perception index 0.89 0.91

Rank 7th 5th 1st 3rd 6th 4th 1st

Explaining adoption behaviour on innovativeness as an individual trait indicates unwillingness, and conceals the inability to adopt. In essence, a fisher or fish farmer may be willing to adopt an innovation but his socio-economic status might be the major factor for his/her inability and not necessarily unwillingness. For the very low cost and other appealing attributes of the ‘gura’ fish trap technology, its diffusion was like an inferno even without any formal disseminating efforts from any extension agents. Hence, the resource poor fisher folks are not only unable to capitalize on the benefits of improved technologies but are placed at a further competitive disadvantage by those who can. CONCLUSION The diffusion of the ‘gura’ technology is simply the result of individual adoption decisions facilitated by interpersonal information sources. The overwhelming factors responsible for the adoption are the technology attributes which tallied with the expectation of the fishermen. The observed variation among the fishers from the two study sites over which attribute most appeal to the respondents was engendered by the differences in their socioeconomic characteristics. However, the problem of effectively harnessing new technologies to meet the needs of rural development is a highly complex one involving all the stakeholders with the government as a regulating entity. RECOMMENDATIONS The following recommendations are therefore proffered for proper management of Gura fish trap technology for sustainability. 1. There is an urgent need to check the use of under mesh sizes and water channel fencing by the research Institutes, Federal Department of Fisheries and States Fishery Departments in their areas of jurisdiction. 2.

The finding of this study tends to underscore the importance of indigenous knowledge system. Hence for technology generation and adoption to be more successful, there is the need for the participation of the clientele who are the intended beneficiaries to be carried along from inception and in line with their indigenous knowledge system.

3.

It is necessary to conduct further studies on the environmental impact assessment arising from the wide acceptance and use of the “gura” trap fishing technology. This will provide avenue for a more rational decision on ways of regulating the impacts of similar technologies on fish species abundance and depletion in lakes, deforestation and ecosystem balance.

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Sule, A.M et al: Continental J. Fisheries and Aquatic Science 3: 12 - 19, 2009

REFERENCES Adeoti A.I. and Ibitoye O.A. (2002). Determinants of participation in urban Agriculture in Ibadan North-West Local Government Area of Oyo State. Journal of Agricultural Extension Vol. 6 pp.34-40. Agbelege, O.O. and Ipinjolu J.K. (2001). Assessment of the exploitation and Management techniques of fish resources in the Nigerian Portion of Lake Chad. Journal of Arid Zone Fisheries Vol. 1: 137p. Agbelege, O.O.; Raji A. and Mofilo M.M. (2003). Fishing gear Survey of Lake Chad. In: Proceedings of the Annual Conference of Fisheries Society of Nigeria (FISON). Maiduguri 4th – 9th November pp. 87-98. Ajayi, A.R. (1998). Role perception of Ondo State Agriculture Teachers in Young Farmers’ Clubs Programme. Journal of Agricultural Extension. A Publication of AESON Vol.2 pp.39-47. Anyanwu A.C; Agwu A.E. and Ibekwe F.N. (2002). Extension potentials of Traditional Management Practices of Muturu Cattle (Bosbrachyceros) in Ebonyi State Nigeria. Journal of Agricultural Extension Vol.6 pp.1-9. Bukar, T. A. and Gubio, A. K.(1985). The Decline of then Commercially Important Species of Clarias lazera in Lake Chad In: Proceedings of the 4th Annual Conference of the Fisheries Society of Nigeria, Port Harcourt 26th-29th November, PP35-41 Kainji Lake Research Institute (1977). A Publication of KLI,New Bussa, Nigeria LCBC (1989). Lake Chad Basin Commission 25th Anniversary Brochure, LCBC Secretariat N’jamena Katz, E; Levin, M.L. and Hamilton, H. (1963). Traditions of Research on the Diffusion of Innovation; American Sociological Review, xxviii, pp.237-252. Luning, H.A. (1982). The impact of technological Change on income distribution in Low-income Agriculture. In: G.E. Jones and M.UJ. rolls (Eds). Progress in Rural Extesnion and community Development. Vol.1. Extension and Relative Advantage in Rural Development pp.21-42. Chichester, U.K: John Wiley. Mohammed S. (1996). Catch Assessment Survey of Kainji Lake NIFFR/GTZ New Bussa, Niger State. Nigeria. Morrison, D.E; Lodwick, D.G; Harris C.G; and Stonmmel, M. (1984). Appropriate Technology as a conceptual Framework for social Assessment. In: H. Schwarz Eller (Ed). Research on Rural Sociology and Rural Development, Vol. 1 Greenwich, Conn. JAI Press. Sarch M.T. and Madakan S.P. (995). Community Management Systems at Lake Chad CEMARE Res. Pap. No. 89, 49. Sule, A.M.; Ayanda, J.O. and Madahli (1994). Preliminary Survey on Sociological Problems of Innovations Adoption of Fishing Technology in Kainji Lake. NIFFR/GTZ New Bussa, Niger State, Nigeria. Received for Publication: 15/07 /2009 Accepted for Publication: 08/09 /2009 Corresponding Author: Sule, A.M National Institute for Freshwater Fisheries Research, P.M.B. 6006, New Bussa, Niger State, Nigeria.

19

Continental J. Fisheries and Aquatic Science 3: 20 - 24, 2009 © Wilolud Online Journals, 2009. IMPACT OF TYPHA GRASS ON FISH CATCH AND DISTRIBUTION IN GUlMBE RIVER KEBBI STATE.. 1

Y. A. Birnin-Yauri1 M.L. Balarabe F. Daddy1, Y. B. Ahmed2 and Owotunse , S1. National Institute for Freshwater Fisheries Research, P.M.B. 6006, New Bussa, Niger State. 2Federal College of Freshwater Fisheries Technology, P.M.B. 1500, New Bussa, Niger State. ABSTRACT: The impact of Typha grass on fish catch composition of different water bodies in Kebbi State was studied. The experimental fishing was conducted, each water body was divided into A and B. A was open water while B Typha infested area. Five Malian traps was set in each area (A and B) for five consecutive fishing days respectively. The fish caught was identified, counted and measured (weight).The various parameters of the plant (Typha grass) was also measured and counted. The results on fish catch composition in terms of numbers and weight in open water was higher than Typha infested area in both dry and wet seasons. KEYWORDS; Fish catch composition, weight in Typha grass area.

INTRODUCTION Typha grass can be found in wetland sedges and meadows along moving streams, rivers banks and lake edges. The plant is found in areas of fluctuating water level such as road side ditches and reservoirs (Morton 1975). It is an erect perennial freshwater aquatic herb which can grow up to 3 or more meters in height. The leaves are thick ribbon like structure which has a spongy cross-section exhibiting air channels. The subterranean stem arises from thick creeping rhizomes. The flower structure is dense, fuzzy, cylindrical spike on the end of stem, with a gap 1-3 cm of naked stem between the upper, male portion (stamina) and lower, female (Pistillate) portion. Both male and female flower sections are roughly length. Male flowers lighter brown; female flowers, often green during bloom dark brown during maturation. Individual blossoms minute and closely on spike (Room 1980). The surface of water cover by Typha grass prevent light penetration, excessive development of algae bloom also causing nuisance in cultivated fish ponds and small reservoirs. They even cause fish mortality due to oxygen depletion or release of extra-cellular metabolites which are toxic (Patnaik 1980). According to (Bennett 1974) “There is evidence that dense stands of Typha grass may bind up nutrient materials throughout the growing season so that they are not available for production of phytoplankton and the organisms that feed upon phytoplankton” This means that although fish hatches would be large, the chances for larva survival would be greatly diminished. The objective of this research was to study the number of fish catch in two different locations. Typha infested and uninfected area so as to proffer some management control. STUDY AREA Kebbi State is located in the North West Zone of Nigeria. An undulating plain with altitude mainly between 350 and 680m above sea level. The area has one main basin, drained by Sokoto Rima rive. The vegetation ecology is distinguishable into the Northern Guinea and Sudan savannah. As result of human activities the trees were replace by shrubs from the South to the Northern boundaries. The area is wholly tropical with abundant solar radiation (400-500 wm-2) incident mostly as beam radiation, 8 hours per day mean and minimum temperature is (17oC) and maximum (32oC) respectively Kebbi has distinct dry and wet season. However they differ slightly in terms of latitude, longititude and amount of rainfall, Kebbi is located on latitude 12o28’N and long. 04o 11’E. Maximum rainfall range 305mm to 1048mm (National Agricultural Research Project, 1996). MATERIALS AND METHODS The study was carried out in all water bodies in Kebbi State, where Typha was infested. Each river (water body) divided into two, A and B, A is open water while B is Typha infested area. Five Malian traps were set up in in each area for five days with dimension of 70cm diameter, 80cm height and 20 kg of baits. The number of fish catch and

20

Y. A. Birnin-Yauri et al., Continental J. Fisheries and Aquatic Science 3: 20 - 24, 2009

weight in each area for two seasons were recorded. The plant height, length of leaves width of the leaves, length of inflorescent, the length of inflorescent tip was also measured, and number of tillers per plant was also counted. The data was analysed. RESULTS Table 1 and 2 shows the number of fish catch and there weight for five days in both A and B for the two season. The result shows increased catch during wet season in Area B Table 3 and 4 showed the morphological features of Typha grass during dry and wet season respectively while Figure 1 showed location A and B where the experiment was conducted. Table 1: Number and weight of fish species caught in Area Aand B during dry season for five days in Kebbi State species Area A Weight(g) Area B Weight(g) Number Number Oreochromis noloticus 42 3710 ___ __ Bagrus bayad

1

100

6

95

Synodontis spp

31

498

___

___

Mormyrops spp

10

920

___

__

Hydrognus forskalii

9

1700

___

___

Malapterutus electricus

6

134

__

___

Heterotis niloticus

2

780

6

141

Lates niloticus

2

145

__

___

Clarias species

7

2570

18

3650

ToTal

110

13,068

30

2,736

21

Y. A. Birnin-Yauri et al., Continental J. Fisheries and Aquatic Science 3: 20 - 24, 2009

Table 2: Number and weight of fish species caught in Area A and B during wet season for five days in Kebbi State species

Area A Number

Weight(g)

Area B Number

Weight(g)

Hemichromis faciatus

5

4500

__

__

Hydrocynus forskalis

15

1150

__

__

Oreochromis noloticus

36

1442

8

180

Bagrus bayad

15

1040

9

978

Clarias species

15

1950

17

2400

Lates niloticus

7

6000

6

1350

Malapterutus electricus

4

1750

2

100

Heterotis niloticus

5

4500

9

539

Synodontis species Total

13 115

1900 24,232

5 56

1000 7,662

Table 3: Morphological features of Typha grass during dry season in Kebbi States. Plant height 2m 2.5m 2.8m 2.5m Length of leaf 2.1m 2m 1.8m 19m Width of leaf 0.5cm 0.4 cm 0.5 cm 0.8 cm Length of inflorescent tip 22cm 31.0 cm 19.6 cm 25 cm Length of inflorescent 42cm 90 cm 36 cm 39 cm No. Of tiller 8 9 10

22

2m 2m 0.8cm 30cm 42cm 5

Y. A. Birnin-Yauri et al., Continental J. Fisheries and Aquatic Science 3: 20 - 24, 2009

Table 4: Morphological features of Typha grass during wet season in Kebbi States. pH 2.0m 2.5m 3m 1.5m length leaf 2m 1.75m 1.75m 2m width of leaf 0.5cm 0.8cm 0.5cm 0.5cm Length of inflorescent tip Non Non Non Non Length of inflorescent Non Non Non Non No. of plant 8 6 5 2

2m 1.8m 0.5cm Non Non 5

Figure 1: A – un-infested by Typha grass in Kebbi State while B –infested by Typha grass in Kebbi State. DISCUSSION The result in Table 1 and 2 shows the fish catch and their weights during the two seasons in A and B. The data analysis showed significant difference in the catch This may be associated with the facts that in B there is always lower catch because in Typha infested area there is low temperature, dissolve oxygen and light penetration. Therefore, few species of fish can survive in that area; Little (1979) reported that Typha decreased dissolve oxygen and lower temperature of the water, which alter the fauna living in water Cook (1976) also observed low temperature and radiation in Typha infested area only few species of fish can survive. When data was analysed between A dry season and A wet season.It showed that there is no significant differences in catch. However there is a change in species and there weights. In B area during dry and wet seasons there is significant difference. This is as a result of increased in number of fish species catch during wet season. The may be associated with the fact that there is less population density of Typha grass during wet season. There is increase in dissolve oxygen and light penetration Patnaiki (1980) oxygen depletion cause low fish catch and fish mortality or release of extra-cellular metabolites which are toxic to fish. There was higher turbidity which makes it difficult for the fish to identify the baits Prowse (1962).Observed High turbidity due to dense phytoplankton lower down catch even sometime lead to total migration of fish. The height of the plant, width of leaves, and length of leaves numbers of tillers showed that there is no significant difference for the two seasons. However, the length of inflorescent and length of inflorescent tip showed significance difference for the two seasons. This is because of absence of inflorescent during wet season. Therefore, the population of plant was less dense; this could explain the reason why the catch was higher during wet season in B. Some of the reasons associated with the higher fish catch in B Typha infested area during wet season because of changes in dissolve oxygen and improve in water turbidity fish turn to spawn in the area. This could also explain the reason why there was diversity of species in B during wet season. Cook (1976) observed that during wet season different species of fish migrate to higher dense aquatic environment. This may be due to season variation in temperature, dissolve and oxygen. REFERENCES Bennet, F.D. (1974). Biological Control. In: D.S. Mitchell (ed.) Aquatic Vegetation and its Use and Control. UNESCO, Paris. 85 – 98 ]Cook, C.D.K. (1965). The aquatic and marsh plant communities of the Kainji Reservoir Site. P. 21 – 42. In: E White (ed.) The First Scientific Report of the Kanji Biological Research Team. University of Liverpool, Liverpool United Kingdom. Little, EC.S. (1969). Weed and man-made lakes. P. 284 – 291. The Accra Symposium, Ghana. University Press, Accra, Ghana Little, EC.S. (1969). Weed and man-made lakes. P. 284 – 291. The Accra Symposium, Ghana. University Press, Accra, Ghana.

23

Y. A. Birnin-Yauri et al., Continental J. Fisheries and Aquatic Science 3: 20 - 24, 2009 Morton, J.F. (1975). Cattails (Typha sp.) Weed: Problem or potential crop? Economic Botany 29: 7 – 29 National Agricultural Research project 1996 pp10-12 Penfound, W.T. 1962. An outline for ecological life histories fo herbaceous vascular hydrophytes. Ecology 33: 123. Patnaik, S., 1980. Toxicity of organic copper compound (cutrine) on some algae and fish. J Inland Fish Soc.India, 12 (1) 136-137 Room, P.M.; Harley, K.L.S.; Forno, I.W. and Sand, S.D.P.A. 1981. Successful biological control of the floating weed, Salvinia. Nature, London. 294: 78 – 80 Received for Publication: 15/07 /2009 Accepted for Publication: 08/09 /2009 Corresponding Author: Y. A. Birnin-Yauri National Institute for Freshwater Fisheries Research, P.M.B. 6006, New Bussa, Niger State.

24

Continental J. Fisheries and Aquatic Science 3: 25 - 36, 2009 © Wilolud Online Journals, 2009. APPROACHES TO STUDYING SEDIMENTATION IN SOME WATER BODIES: AN OVERVIEW Gwari, B. M. and Ugoala, C. National Institute for Freshwater Fisheries Research, P. M. B. 6006, New Bussa 913003, Niger State

ABSTRACT The rate of sedimentation and the consequent loss of valuable water storage is becoming increasingly important in most developing nations. There are evidences of steady rise in soil erosion endangering reservoir projects which cause doubts about the viability of existing and future schemes. The impoundment of water for potable and irrigation supplies, hydropower, and flood control is a necessary step towards socio-economic development. Untimely sedimentation process of most water bodies may reduce the benefits and, if it is ignored, remedial measures may become either prohibitively expensive or technically unfeasible. Therefore the objective of this research was to highlight the various methods for studying sedimentation. It is therefore hoped that this paper will help in addressing persistent problems of sedimentation in many developing nations. KEYWORDS: Sediments, Deposition, Loads, Water velocity, Aquatic community INTRODUCTION A large number of natural and man-made lakes in Nigeria are picturesque and most of them are utilized for human consumption, irrigation and power generation purposes (Kainji, Jebba, Shiroro). However, increasing anthropogenic activities in the past few decades have greatly affected the hydrological regime of the lakes. Consequently, inflow of eroded material and other contaminants from the lcatchments has accelerated the rate of sedimentation and eutrophication processes. Sedimentary Processes within wetlands are intimately connected with many wetland functions, the most important effect of which is the influence on water quality (Johnston, 1991; Gilliam, 1994; Mitsch and Gosselink, 2000). Since wetlands function as sources, sinks, and transformers of materials, they have the potential to positively or negatively affect water quality by trapping or transporting excess nutrients, harmful chemicals, and other high material loads. Low water velocities cause wetlands to act as depositional environments for sediments suspended in water, and thus for nutrients and other chemicals sorbed to sediments (Phillips, 1989). Higher rate of sedimentation has diminished the usefulness of several small lakes and many others are shrinking at an alarming rate. Hence, knowledge of accurate sedimentation rate and its causes are of utmost importance for appropriate management of lakes and future planning. Physico-chemical and biological characteristics of various lakes in the country have been studied in detail, but few studies have been carried out to estimate the sedimentation rate and deposition pattern in lakes. Freshwater wetlands are highly effective in nutrient retention, especially as phosphorus sinks (Mitsch et al., 1977, 1979a,b; Craft and Richardson, 1993; Meeker, 1996). Other studies have examined the physical factors that affect sedimentation in freshwater systems (Kadlec and Robbins, 1984; Hupp and Blazemore, 1993; Kleiss, 1996; Wardrop and Brooks, 1998; Braskerud et al., 2000; Braskerud, 2001). These studies have recognized the importance of factors such as basin morphology, hydrology, and biota, but further research is needed to determine how these factors interact together to influence sediment dynamics at the ecosystem level. Only very limited research has been done to date that examines sedimentation in created freshwater wetlands (Brueske and Barrett, 1994; Fennessy et al., 1994; Braskerud et al., 2000; Braskerud, 2001). More in-depth knowledge of sedimentary processes in freshwater wetlands is needed for not only answering questions of basic wetland science, but also for practical applications as more natural and created freshwater wetlands come into use for water quality improvement. Understanding freshwater wetland sedimentary processes gives insight into the complexity of organic and inorganic matter cycles, improves created wetland design, and refines predictions about the functional lifetime of these systems. Much of the existing sedimentation research comes from work in coastal marshes and river deltas and examines the relationship between marsh or land accretion and coastal subsidence (Cahoon and Turner, 1989; Knaus and Van Gent, 1989; Cahoon, 1994; Roman et al., 1997; Reed et al., 1997; Hensel et al., 1999; Day et al., 1999; Yang, 1999).

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Gwari, B. M. and Ugoala, C: Continental J. Fisheries and Aquatic Science 3: 25 - 36, 2009

This research has generated most of the current knowledge of wetland sedimentary processes and sediment measurement techniques. Sediments stored in lakes represent a valuable archive that can be used to reveal the erosion history of watersheds. A portion of the soil that is moved down gradient during runoff events is deposited in lakes, and the rate at which sediment accumulates should be proportional to the rate of erosion from the surrounding land. The ability to calculate the rate at which this sediment has accumulated over discrete time intervals in the past opens several opportunities for improved understanding and management of watershed processes. Examples include quantifying changes in erosion and deposition rates caused by anthropogenic or natural shifts in land use or by climate change. Future efforts to conserve soil resources can be better justified if post-clearing increases in erosion rates can be quantified rather than simply inferred. Knowing the amount by which management practices reduce erosion rates can also help to justify expenditures by quantifying the effectiveness of the practices in comparison to ancient erosion rates. The ability to roll back time and peer into the erosion/sedimentation history of watersheds is a valuable tool for evaluating current land-management practices. Recently sedimentation menace has become a global affair (USEP, 1994; Glysson and Gray, 2002). Halstead (1974) and Adegoke and Kogbe (1974) has identified sedimentation problem in Nigeria. Since then the techniques of studying this geomorphic phenomenon vary in both approach and conceptualization. This paper therefore employs literature search to expose prospective researchers to the available methodology in sedimentation studies. INLAND WATER RESOURCES OF NIGERIA Nigeria is blessed with a vast expanse of inland freshwater and brackish ecosystems. Their full extent varies with season and from year to year depending on rainfall. However, these water resources are spread all over the country from the coastal region to the arid zone of the Lake Chad Basin. Table 1: Major inland water resources of Nigeria Types of water bodies Approximate A: Major Rivers Anambra River Benue River Cross River Imo River Qua Iboe River

1,401,000 129,000 3,900,000 910,000 500,200

Ogun River Niger River

2,237,000 169,800

B: Major Man-made Lakes and Reservoirs Lake Chad (natural) Kainji Lake Jebba Lake Shiroro Lake Goronyo Lake Tiga Lake Chalawa Gorge Dadin Kowa Kiri Bakolori Lower Anambra Zobe Oyan

550,000 127,000 35,000 31,200 20,000 17,800 10,100 29,000 11,500 8,000 5,000 5,000 4,000

26

reference area(ha)

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Gwari, B. M. and Ugoala, C: Continental J. Fisheries and Aquatic Science 3: 25 - 36, 2009

Table 2: Distribution and extent of Nigerian brackish and fresh water bodies in hectres Approximate size (ha)UUUuuuu Deltas and estuaries Niger delta 617,000 Cross River estuary 95,000 Imo and Qua Iboe estuary 36,000 Others 110,000 Freshwaters Niger delta freshwater Apex of delta to Lokoja Niger/Sokoto Basin Niger Kaduna Basin Lower Niger: Jebba to Lokoja Benue River floodplain Hadejia Komadugu Yobe Ogun/Oshun floodplains Cross River floodplains Imo River floodplains Qua Iboe

362,000 635,000 470,000 150,000 385,500 312,000 624,000 Not estimated 250,000 26,000 7,000

POTENTIAL BIOLOGICAL EFFECTS OF SEDIMENTATION IN AQUATIC ENVIRONMENTS Potential detrimental effects of sedimentation in aquatic environments generally fall into two categories: water column effects (i.e. exposure to suspended sediments) and sedimentation effects. Most sessile or bottom-oriented aquatic organisms encounter some degree of sedimentation under natural conditions, and many have morphological, behavioral and/or physiological means of dealing with exposure to deposited sediments. Natural sedimentation rates vary widely both within and between habitats and depend on numerous environmental factors. In addition, where salt and fresh waters mix, flocculation (the aggregation of small particulates such as clay and organic detritus) may affect settlement rates. Since salinity, temperature, pH, and the type of sediments in suspension influence flocculation, predicting the transport and settlement of sediments under highly variable estuarine conditions may be problematic (Galtsoff, 1964). Effects of sedimentation on biota may be direct, indirect, or both. Direct effects include smothering (manifested by decreased gas exchange), toxicity (exposure to anaerobic sediment layers), reduced light intensity, and physical abrasion. Indirect effects include changes in habitat quality; particularly substratum characteristics (e.g., altered sediment composition resulting in reduced availability of in faunal prey species). Deleterious effects of excess sedimentation in the freshwater and marine environment are: (i) Possible reduction in oxygen levels in surface waters, eutrophication, increased acidity and toxicity; (ii) Burial of sessile aquatic fauna and flora at greater than recovery rates and reduction of suitable habitats; (iii) Loss of open water, decreased water depth, increased muddiness of sediments; (iv) Increased turbidity of surface waters leading to a decrease in light penetration of the inner water.

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Gwari, B. M. and Ugoala, C: Continental J. Fisheries and Aquatic Science 3: 25 - 36, 2009

Figure 1. Showing how enhanced sedimentation rates can lead to the smothering of benthic communities.

Lagoons. Exchange between the Lagoon and the sea is limited through inlets. The resulting brackish water is moved more by the wind than by the tide and does not flow from headwaters to a mouth like a river. Lagoons are therefore delicate ecosystems whose balance is easily upset through excessive inputs of either fresh or marine waters. Being close to land they tend to be highly polluted and sediments discharged directly into them. They are of high value to fisheries, since the quiet waters are ideal for juvenile and larval forms of fish and crustaceans. Submerged Aquatic Vegetation. Loss of sea grass habitat is a major environmental concern caused by various types of disturbances in coastal and estuarine environments. Declining water quality, including increased turbidity, nutrient loading and reduced light penetration contributes to the loss of sea grass habitat in many systems (Zieman and Zieman 1989; Robblee et al.1991; Durako1994). Dredging impacts on sea grass habitat can be acute, i.e., the direct killing or removal of the plant; or chronic, through the creation of conditions in which individual species lose their ability to compete with other species for light, nutrients, and space. Sea grasses have the ability to withstand limited burial through several species-specific mechanisms, involving the growth form, the depth to which the plant is covered, and the properties of the sediment (particularly the depth of the anaerobic layer). Direct mortality may result if plant elongation and growth rates are insufficient to surpass sediment accretion rates. If sea grasses are only lightly covered and the rhizome system is not damaged, re-growth through the sediment may be possible. Moderate levels of sediment deposition can lead to increased vertical growth relocating the meristems (growth centers) closer to the sediment surface such that the photosynthetic portions are located in the proper light regime and effective gas exchange may occur. Suspension of unconsolidated deposited sediments has been hypothesized to cause the decline of sea grass habitat. Altered substrate surfaces from dredge and fill operations may reduce the quantity of photosynthetically active radiation (PAR) available to submerged aquatic macrophytes and other aquatic plants (Onuf 1994, Dawes et al.1995, Tomasko et al.1996). Reduced PAR may result in lower productivity and limit the depth distribution of sea grass beds. Zimmerman et al. (1991) reported that depth distributions of Zostera marina could be limited more by extremes in turbidity than mean turbidity level. Moore et al.(1997) and Longstaff and Dennison (1999) have both documented deleterious impacts to sea grasses exposed to pulsed turbidity events lasting a month or more. Because dredged material deposits can initially be more readily suspension than native sediments, the duration of suspension events and concentration of suspended sediments may be higher near dredged material disposal sites, thus affecting sea grass populations (Zieman and Zieman 1989; Onuf 1994).

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Mangroves. They are characterize by the alternation of tidal floods (intertidal areas) and the presence of freshwater, at least temporarily. Ellison (1999) reported that most mangroves can tolerate sedimentation rates ranging from less than 5 mm to 10 mm per year. Burial of the aerial roots in 10 cm or more of sediment was generally lethal, although substantial differences existed among species. Excess input of sediment can, however, cause death of trees due to root smothering. Indirect degradation of mangroves has been attributed to upstream diversion of freshwaters and pollution caused by oil spills, heavy metals, pesticides and nutrients. Fishes. Berry et al (2003) stated that adults and juveniles of most species of fish avoid areas of temporarily high sedimentation and return at a later time. Eggs of bottom-spawning species, survival of larval stages living in and around the substratum, and in substratum sediment composition as well as demersal or non-buoyant eggs that may either remain adhered to spawning sites or be carried by bottom currents are additionally exposed to sedimentation and burial (LaSalle et al. 1991). Shellfish. Benthic organisms use deposited sediments as habitat, substrate, and a source of nutrition. This group includes many commercially important invertebrates including mobile crustaceans (e.g., lobsters, crabs and shrimps) and sessile molluscs (e.g., oysters and clams). Crustaceans. Many crustaceans are mobile macro benthic predators that reside on or near the bottom where sedimentation occurs and can presumably emigrate from an area when it becomes inhospitable (unlike clams and oysters). Lobsters, crabs, and shrimp spend at least some portion of their life cycle in estuaries or near shore coastal habitats where they are exposed to turbid water conditions. While these organisms are dependent on the stability of sediments, they show varying degrees of physiological and behavioral characteristics consistent with the sedimentation regimes of their respective habitats. The loss of suitable habitat used as shelter by juveniles of both species may increase competition for the remaining available shelters. Crowding reduces growth rates in lobsters and increases the time spent searching for non-silted areas, which may prolong exposure to predation and result in higher mortality rates. Molluscs. Sedimentation on oyster habitats is a common natural phenomenon due to their location near the mouths of sediment-laden rivers. Sedimentation impacts to oysters may occur by direct morality caused by burial in a relatively deep sediment layer, reduction in oyster growth, or by the inhibition of settlement of oyster spat caused by a deposit of sediment. Sedimentation can also negatively affect organisms associated with oyster reef habitats such as fishes and crabs that rely on the interstices in the oyster shell as habitat for colonization and refuge from predation. Larger interstitial areas among the oyster shells are also associated with enhanced oyster growth (Bartol and Mann, 1999; Posey et al., 1999; O’Beirn et al., 2000). Corals and Tropical Coral Reefs. Heavy sedimentation on corals is associated with reduced coral species diversity, less live coral, lower coral growth rates, greater abundance of branching forms, reduced coral recruitment, decreased calcification, decreased net productivity and slower rates of reef accretion (Rogers, 1990). The distribution of some coral communities has been related to suspended sediment load (West and van Woesik, 2001). Adverse impacts to corals and coral reef organisms from sedimentation may extend beyond the reef systems to tropical fisheries. Sedimentation that impacts corals and sponges may ultimately affect many fish and shellfish that use these resources for food and shelter. It has long been recognized that sedimentation, due to dredging as well as natural causes, is a major factor controlling the distribution and abundance of corals. Reefs in areas with low sedimentation rates are generally better developed, have more coral species, higher coral cover, and faster rates of frame work accretion than those subject to heavy sedimentation (Loya, 1976; Dodge and Vaisnys, 1977). Sedimentation affects coral growth in several ways including larval settlement (Te1, 992). Coral larvae settle preferentially on vertical surfaces to avoid sediments and cannot successfully establish themselves in shifting sediment. An increase in site-specific substratum sediment load can affect total numbers of individuals recruiting to a particular location as well as relative species abundance. For adult corals, if sediment accumulates faster than the ability of the coral to remove it, the ensuing shading may compromise the ability of algal endosymbionts to photosynthesize and an anoxic layer may develop, which kills the underlying tissue. Even if sedimentation does not result in direct mortality, exposure to sediments may cause stress. Several species of coral are characteristically found in areas with high rates of sedimentation and solute suspension. These corals, which include Montastrea cavernosa, Diploriastrigosa, and

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Siderastrea siderea, are effective at clearing sediment, which appears to bean important adaptation in their ability to colonize and compete in areas where sedimentation is common (Lasker 1980). METHODS OF SEDIMENTATION STUDIES Quantitative assessment of sedimentation is always difficult because sediment concentrations and settling rates are extremely variable, depending on the detailed history of rain, wind, and waves at each site. Historical flow and sediment-transport data from sites across the water body can be used to develop sedimenttransport rating relations and substrate-composition data. Annual suspended-sediment loads can be calculated for all sites to determine regional trends for stable and unstable sites. Trends of bed-material composition can similarly be identified. Geomorphic assessments can be conducted to determine the relative stability of the stream and to sort sites into stable and unstable groupings. Statistical analysis of sediment-transport rating relations will determine if characteristic relations can be enveloped for streams of given stability and bed-material characteristics. These data can be used to investigate the possibility of establishing empirical, dimensionless sediment ratings for un-gauged streams. The relative stability of streambeds and the likelihood that rates of bed erosion or deposition exceed background rates can be estimated at gagged sites using an excess shear-stress approach. Potential links between sediment-transport rates, bed-material conditions and aquatic indices can be investigated using both an empiricalstatistical approach using historical data from throughout the region where data are available, and by making simultaneous measurements and sampling of flow, sediment transport conditions and aquatic-community structure at two stable and unstable sites. These data are compared with existing ecological data to provide a means of differentiating impacted from non-disturbed systems. Radiometric dating techniques are reliable tools for estimating sedimentation rates in lakes and are used worldwide. Although several radioisotopes are useful in geochronological studies of sediments, lead-210 (210Pb) and caesium137 (137Cs) isotopes find the largest application. In radiometric dating, sediment cores ranging up to 60 cm in length are collected from different parts of selected lakes using a gravity corer. Four to five of these cores are selected for dating the sediment and as representatives of the sedimentary environment on the basis of bottom topography and drains entering the lakes. The cores are sliced at every 2 cm intervals and analysed for 210Pb and 137Cs activities to identify sedimentation rates, chemical characteristics, and textural characteristics of sediments. Where needed, highresolution acoustic profiling can be used to enhance the quality of data collected from reservoirs. Local and regional trends in reservoir sedimentation are be defined where possible. The stream erosion algorithms from the one-dimensional channel evolution model concepts can be modified for implementation in multi-dimensional computer models of stream morphology. The algorithm is tested for accuracy on streams impacted by dam and reservoir operations. Physical model experiments are conducted on the storage and transport rate of sand introduced to a previously established bed comprised only of gravel. The main outputs of this work are the depth of penetration of sand into the bed in which the sand is stored and the eventual transport rate and bed surface size distribution. This knowledge is important to improve computer model predictions of streambed elevation, composition of streambed materials, and fractional sediment transport rates downstream of dams after sand-sized sediment releases. SEDIMENTATION RATES Vertical accumulation (mm yr-1) Changes in the rate at which estuaries have been vertically filling up with sediment can provide useful insights into the functioning and health of an estuary. Marked increases in modern rates of infilling may reflect increased catchment erosion and/or the increased production of organic sediment within the estuary, and indicate that abrupt changes have occurred in estuarine geomorphology and benthic habitats (Appleby and Oldfield 1992). Mass accumulation (g cm2 yr-1) Sediment mass accumulation is a more accurate measure of sedimentation where there are significant changes with depth in the density of estuarine sediment that may be related to compaction or changes in the composition of the sediment (Hancock and Hunter 1999, Hancock, 2000).

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Significance of sedimentation rates Sedimentation rate data can be used to determine whether a waterway has been subject to enhanced sediment loads due to changes in catchment land use practices. Enhanced sedimentation rates can bring about rapid changes in the form and function of coastal waterways. Some natural controls on the sedimentation rates experienced by coastal waterways include climate (rainfall, seasonality), geology, slope (or topography), vegetation and the size of the catchment. Habitats may be smothered where sediment is deposited more rapidly than tolerated by benthic communities. For example, loss of seagrass and macroalgae destabilises bottom sediments formerly protected from wind and tidal erosion by the sheltering and binding abilities of macrophyte colonies (May and Stephens 1996, Hancock et al, 2001). Such changes also constitute pressures on fish assemblages and benthic invertebrate numbers. Turbidity levels and the amount of sediment-bound nutrients (e.g. Total P, Total N and Total Organic Carbon), trace elements (e.g. Fe, Zn, Pb) and other toxicants entering estuaries from their catchments also tend to increase in association with increased rates of sedimentation (McComb and Lukatelich 1995). Greater nutrient loads can lead to periods of eutrophication which can further enhance sedimentation rates because the amount of organic matter being deposited also increases. Table 3. Sedimentation rates for some water bodies as observed by the authors AUTHOR YEAR WATER RATES BODY McLaughin 2000 Sydney 10-15 M/year Harbour Hancock 2000 Bega River 3.1-3.4 mm a-1 Jones and Chenhall 2001 Sydney 1.2-3 mm a-1 lagoon Sloss 2001 Illawara lake 1.2-3 mm a-1 Jones and Chenhall, 2001 Sydney 0.9-2.2 mm a-1 estuaries Baumber, 2001 Wollumboola 0.47-0.71 mm a-1 lake Hancock 2001 Moreton bay <6.2, <12 mm a-1 Logan et al 2002 Lake Wallis 1.4-2.6mm/year Brooke 2002 Tweed River 0.2, 0.3 mm a-1 Sloss et al 2004 New 0.2-0.55mm/year southwales Chin-AnHum et al 2006 Koping River 0.06-1.6cm/year Rogata et al 2007 Nipigon 0-1.5cm/year Lake Kostaschuk et al 2008 Fundy Bay 1.1cm/year Kamaruzzaman and 2008 Kemaman0.94-1.11cm/year Ong Chulkan mangrove Chuanshun et al 2009 Southwestern 1.8 and 21.2m Ka Okinawa River

TECHNIQUE Hydrographic survey 210 14

14

Pb C, 137Cs, AAR C, 137Cs, AAR Pb, Pollen

210

14

C,210Pb

210

Pb, 137Cs Pollen 14 210 C, Pb, Pollen Aspartic acid 210 137

210 210

Pb Cerium Pb and 137Cs Pb

AMS, 14C

Increased sedimentation rates also allow more organic matter to be degraded by anoxic processes because the exposure time of organic matter to dissolved oxygen in the water column is shortened. Denitrification efficiencies are lowered under anoxic conditions, and more dissolved nutrients are recycled to the water column. Loss of

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Gwari, B. M. and Ugoala, C: Continental J. Fisheries and Aquatic Science 3: 25 - 36, 2009

nitrification and denitrification (and increased ammonium efflux from sediment) in coastal and estuarine systems is also an important cause of hysteresis. The net result of enhanced sedimentation rates is an increase in the maturity of coastal waterways, and a decrease in their overall life-spans. Reductions in the biodiversity, health and integrity of coastal ecosystems may also occur. In order to make better-informed management decisions there is clearly a need to accurately assess the rate and nature of sedimentation within coastal waterways and any changes in other sedimentological parameters over time (Hodgkin and Clarke 1989). Other geochemical analyses of sediment cores can identify pools of nutrients or other pollutants within the estuary fill. This is important information for managers because of the potential for the release of sediment-bound nutrients into the water column, which is also relevant where dredging work is proposed. The identification of microfossils in sediment cores can provide a detailed record of recent changes in estuarine vegetation communities or harmful algal blooms (Harle et al, 2002; Appleby and Oldfield 1992). Sedimentological data are especially important where conservation or restoration actions are being planned and there is a lack of historical information to indicate how the estuarine environment has changed over the past two centuries or past few decades. Likewise, these data can aid in the development of models of sediment transportation. The information gained from the analysis of sediment cores, therefore, needs to be viewed as basic environmental data needed for the effective management of estuarine systems. CONCLUSION Sediments stored in water bodies represent a valuable archive that can be used to reveal the erosion history of these resources. A portion of the soil that is moved down gradient during runoff events is deposited in lakes, and the rate at which sediment accumulates should be proportional to the rate of erosion from the surrounding land. The ability to calculate the rate at which this sediment has accumulated over discrete time intervals in the past opens several opportunities for improved understanding and management of the resource processes. Examples include quantifying changes in erosion and deposition rates caused by anthropogenic or natural shifts in land use or by climate change. Future efforts to conserve soil resources can be better justified if post-clearing increases in erosion rates can be quantified rather than simply inferred. Knowing the amount by which management practices reduce erosion rates can also help to justify expenditures by quantifying the effectiveness of the practices in comparison to ancient erosion rates. The ability to roll back time and peer into the erosion/sedimentation history of ponds, lakes, rivers, reservoirs and even oceans is a valuable tool for evaluating current land-management practices. REFERENCES Adegoke, S. O. and Kogbe C. A. (1994) Littoral and suspended sediment of Lake Kainji.The ecology and geology of Lake Kainji. Geology and Sedimentology. Appleby, P.G. and Oldfield, F. (1992). Application of lead-210 to sedimentation studies. In Ivanovich, M. and Harmon, R.S. (Eds), Uranium-series Disequilibrium: Applications to the Earth, Marine and Environmental Sciences. Clarendon Press, Oxford, pp. 731-778. Berry, W., Rubenstein, N., Melzian, B., and Hill, B. (2003). “The biological effects of suspended and bedded sediments (SABS) in Aquatic Systems: A review,” Internal report to US EPA, Office of Research and Development, National Health and Environmental Effects Laboratory, Narragansett, RI. Bartol, I., and Mann, R. (1999). “Small-scale patterns of recruitment on a constructed intertidal reef: The role of spatial refugia,” Oyster reef habitat restoration: A synopsis and synthesis of approaches Barnett, E. J. (1994). A Holocene paleo-environmental history of Lake Alexandrina. Journal of aleolimnology, 12, 259-268. Baumber, A. (2001). Holocene infill and evolution of Lake Wollumboola, a saline coastal lake on the NSW south coast. Research Report, Environmental Science Program University of Wollongong.

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Robblee, M. B., Barber, T. R., Carlson, P. R., Durako, M. J., Fourqurean, J. W., Muehlstein, L. K, Porter, D., Yarboro, L. A., Zieman, L. A., and Zieman, R. T. (1991). “Mass mortality of the tropical seagrass Thalassia testudinum in Florida (USA),” Marine Ecology Progress Series 71, 297-299. Rogers, C. S. (1990). “Responses of coral reefs and reef organisms to sedimentation,” Marine Series 62, 185-202.

Ecology Progress

Roman, C. T., Peck, J. A.; Allen, J. R.; King, J. W. and Appleby, P. G. (1997). Accretion of a New England (U.S.A.) salt marsh in response to inlet migration, storms, and sea-level rise. Estuarine Coastal Shelf Sci. 45:717–727. Sloss, C. (2001). Holocene stratigraphic evolution and recent sedimentological trends, Lake Unpublished BSc Honours Thesis, School of Geoscience, University of Wollongong.

Illawarra, NSW.

Sloss, C. R., Murray-Wallace, C.V., Jones, B. G., Wallin, T., (2004). Aspartic acid racemisation dating of mid-Holocene to recent estuarine sedimentation in New South Wales, Australia: a pilot study. Marine Geology, In Press. US Enviromental Protection Agency (1994). Great Lake Contaminant Assessment Document. Chicago 3. Great Lakes National Program office. Tomasko, D.A., Dawes, C. J., and Hall, M. O. (1996). “The effects of anthropogenic nutrient enrichment in turtle grass (Thalassia testudinum) in Sarasota Bay, Florida (U.S.A.),” Estuaries 19, 448-456 West, K., and Van Woesik, R. (2001). “Spatial and temporal variance of river discharge on Okinawa inferring the temporal impact on adjacent coral reefs,”Marine Pollution Bulletin 42, 864-872.

(Japan):

Wardrop, D. H. and Brooks, R. P. (1998). The occurrence and impact of sedimentation in central Pennsylvania. Environ. Monit. Assess. 51:119–130. Yang, S. L. (1999). Tidal wetland sedimentation in the Yangtze Delta. J. Coastal Res. 15:1091–1099 Zimmerman, R. C., Reguzzoni, J. L., Wyllie-Echeverria, S., Josselyn, M., and Alberte, R. S., (1991). “Assessment of environmental suitability for growth of Zostera marina L. (eelgrass) in San Francisco Bay,” Aquatic Botany 39:353-366. Zieman, J. C., and Zieman, R. T., (1989). “The ecology of the seagrass meadows of the West Coast of Florida: A community profile,” U.S. Fish and Wildlife Service Biological Report 85(7.25), Washington, DC. Received for Publication: 15/07 /2009 Accepted for Publication: 08/09 /2009

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Continental J. Fisheries and Aquatic Science 3: 37 - 41, 2009 © Wilolud Online Journals, 2009.

EFFECT OF BAITS TYPE ON FISH CONGREGATION AND CATCH EFFICIENCY OF CASTNET IN LAKE KAINJI, NIGERIA. Y.B. Ahmed1, L.A. Argungu2 and T.A. Tagago3 Federal College Of Freshwater Fisheries Technology,P.M.B. 1500, New Bussa, Niger State.2Department of Forestry and Fisheries,Usmanu Danfodiyo University,P.M. 2346, Sokoto, Nigeria.3Kebbi Agricultural and Rural Development Authority,Birnin Kebbi, Kebbi State. 1

ABSTRACT The effect of baits, rice bran (Oryza sativa L.) and corn bran (Zea mays L.) on fish aggregation and catch efficiency of castnet in Lake Kainji was conducted. 25.4mm stretched mesh size multifilament (PA) nylon net was used for the construction of castnet. The experiment was Complete Randomized Design (CRD) with three replications for nineteen consecutive fishing days. Three treatments were employed; castnetting after baiting with rice bran, with corn-bran, and castneting without bait (control). Thirteen fish species were caught from eight families. The number of fish caught was 336, of which 48.5 and 27.1% were castnetting with corn bran and without bait while castnetting with rice bran recorded the least (24.4%). The biomass of fish caught was 4627.7g (4.6kg) of which the highest percentages 51.4 and 28.6% followed same trend as that of number of fish caught. Comparison of the overall number and biomass of fish capture indicated that Tilapia zilli ranked highest, next by Citharinus citharus and Hydrocynus forskalii. Recommendations have been made for areas of further studies in these aspects. INTRODUCTION Castnet fishing is regarded as a traditional method of catching fish that has been used since antiquity. The most widely used artisanal fishing gears in Nigerian freshwater and brackish water as well as coastal waters, are gillnets and castnets (FAO, 1969). Castnet are conical falling nets with lead (Pb) weights attached at regular intervals along the perimeter of the cone (Udolisa and Solarin, 1979). It is an active fishing gear; that is it catches fish instantly. Hayes et al. (1996) reported that a light or bait is often used to attract the target fish into an area within the castnet’s range. Fishing baits lures and attraction devices, are often incorporated into some fishing gears in order to improve their efficiency such fishing gears include handlines, longlines, trolling and traps etc (Ahmed et al, 2005). Baits may include rotten meat, dead or live fish, palm nuts or corn bran depending on the feeding and behavioral characteristics of the target fish species. The castnet fishery is probably the next most damaging fishing method to juvenile fish after beach seines (du Feu and Abiodun, 1999). It caught 34% of the total tilapines, 24% Citharinus and 19% of all Labeo, at a mean size upto 50% less than gillnets in the case of Citharinus. This study therefore intends to assess the effects of two baits rice bran (Oryza sativa L.) and corn bran (Zea mays L.) and, without baits on the efficiency of castnet in Lake Kainji. MATERIALS AND METHODS The experiment was conducted in the lower basin of Lake Kainji about 6.5 km away from the Federal College of Freshwater Fisheries Technology, New Bussa, Niger State, between July and August, 2008. The description of study area is adequately made in Ahmed et al, (2006). The castnet construction was followed by the same method that was used by Udolisa et al. (1994) and Udolisa and Solarin (1979). Two types of baits were used corn bran and rice bran, and casneting without bait was used as control. A net was cast, a waiting period of five minutes was observed to allow the weight to settle to the bottom of the sampling areas. The net was pulled with both hands to retrieve it. The experiment was Complete Randomized Design (CRD) with three replications for nineteen consecutive fishing days. The fish caught were packed in separate labelled container for each treatment.

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Y.B. Ahmed et al.,: Continental J. Fisheries and Aquatic Science 3: 37 - 41, 2009

The data were collected on species, number, length (cm) using metric ruler and weight (g) using Ohaus compact scale model CS200 of 200g capacity for each fish caught and recorded according to respective treatments. The fish species were identified following the description of Olaosebikan and Raji (2004). Simple statistical tool was employed (mean and percentage) (SPSS, 1999). Species diversity index (SDI) was computed following Ahmed et al, (2006) modified method. RESULTS AND DISCUSSION Types of Fish species Caught by Castnet using different baits in Lake Kainji. The types of fish species captured comprise thirteen species belonging to eight fish families as shown in Table 1. The fish species diversity index showed that castnetting with corn bran had the highest value of 0.92, while castnetting without bait recorded 0.77 and with rice bran 0.69. Cichlidae family was represented by five species, Characidae with two species and the rest were represented by only one species each. Baits, lures or attraction devices are often incorporated into some fishing gears inorder to improve their efficiency (Ahmed et al. 2005). Fish species that are dispersed over a wide range area can be congregated or concentrated into a smaller area where an appropriate fishing gear can be operated to get them. Congregation of fish before harvest had been reported by many authors using luring methods that are economically and environmentally friendly (Udolisa and Solalrin, 1979; Solarin and Kusemiju, 2003). The fish species caught are from eight families, this shows that castnet is an efficient fishing gear for encountering fish species of diverse feeding and behavioral characteristics. Number and percentages of fish Caught by castnet using different baits type in Lake Kainji. Table 1 contains the number and percentages of fish caught with respect to the different treatments (baits). The total number of fish caught was 336, of which 48.5 and 27.1% were caught in castnetting with corn bran and castnetting without bait (control) respectively, while the least number (24.4%) was recorded in castnetting with rice bran. The findings in the present study show low catchability compared to that of Udolisa and Solarin (1979) at Ikorodu beach in the Lagos Lagoon, Tilapia spp are caught in large number about 5-10kg by spreading gari (Processed CassavaManihot utilisina) on marked spots and castnets are thrown over the area. The reason for the low catch in the study area has already been reported by Seisay and du Feu (1997) who observed a reduction in mean sizes in fish species and changes in species compositions due to both requirement and ecosystem over-fishing. Comparison of the overall number of fish caught shows that T. zilli contributed the highest percentage, being 29.5% next by C. citharus 15.5%. Moreover, the dominant fish in the catches of castnet with corn bran was T. zilli that contributed 31.9%. In castnetting without bait C. citharus accounted for 38.5% while in fish entice with rice bran T. zilli accounted for 36.6% ranked next to this species was H. forskalii.

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Y.B. Ahmed et al.,: Continental J. Fisheries and Aquatic Science 3: 37 - 41, 2009

Table 1: Types, number and percentages of various fish species caught by Castnet during different baits type in Lake Kainji.

Family

Characidae

Cichlidae

Citharinidae Claroteidae Cyprinidae Distichodontidae Mochokidae Mormyridae Total number of fish caught Relative Percentage Total species caught Species Diversity Index (SDI).

Species

H. forskalii Alestes baremoze H. bimaculatus H. fasciatus Sarotherodon galilaeus Oreochromis niloticus T. zilli. C. citharus C. nigrodigitatus Labeo coubie Distichodus rostratus S. membranaceus M. budgeti

BAITS Corn bran Rice bran Number PerNumber Percentage centage 20 12.3 17 20.7 1 0.6 3 3.7

Without bait Number Percentage 15 16.5 4 4.4

Overall catch Total Percentage 52 15.5 8 2.4

4

2.5

2

2.4

1

1.1

7

2.1

13 7

7.9 4.3

8 5

9.8 6.1

6 1

6.6 1.1

27 13

8.0 3.9

14

8.6

9

11.0

10

10.9

33

9.8

52 17 19

31.9 10.4 11.7

30 7

36.6 8.5

17 35 1

18.7 38.5 1.1

99 52 27

29.5 15.5 8.0

3 -

1.8 -

1

1.2

1 -

1.1 -

4 1

1.2 0.3

6

3.7

-

-

-

-

6

1.8

7 163

4.3 100

82

100

91

100

7 336

2.1 100

48.5

24.4

27.1

12

9

10

0.92

0.69

0.77

Biomass and Percentages of fish species caught by castnet using different baits in the Lake Kainji. The biomass of fish caught by castnetting using different baits are shown in Table 2. The total weight was 4627.7g (4.6kg) of which the greatest proportion 51.4 and 28.6% was captured in castnet baited with corn bran and without bait (control) while castnetting with rice bran recorded the least (20%). T. zilli, C. citharus, and H. forskalii contributed 25.4, 21.3 and 14.2 percents of the overall weight of fish caught. Comparison of the overall weight of the fish caught shows that fish entice with Corn bran T. zilli recorded for 29.3%, followed by C. citharus (15.6%). In castnetting with rice bran T. zilli accounted for 30.7% followed by H. forskalii while castnetting without bait (control) C. citharus contributed 46.4%.

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Y.B. Ahmed et al.,: Continental J. Fisheries and Aquatic Science 3: 37 - 41, 2009

Table 2: Biomass and percentages of various fish species caught by Castnet using different baits type in Lake Kainji. BAITS Species Corn bran Rice bran Without bait Overall catch Weight Percentage Weight Percentage Weight Percentage Total Percentage (g) (g) (g) Weight (g) H. forskalii 224.0 9.4 182.2 19.6 253.2 19.1 659.5 14.2 Alestes 25.1 1.1 58.9 6.4 46.8 3.5 130.8 2.8 baremoze H. bimaculatus 30 1.3 22.7 2.4 8.5 0.6 61.2 1.3 H. fasciatus 123.2 5.2 130.7 14.1 61 4.6 314.9 6.8 Sarotherodon galilaeus Oreochromis niloticus T. zilli. C. citharus C. nigrodigitatus Labeo coubie Distichodus rostratus S. membranaceus M. budgeti Total weight of fish caught Relative percentage

89.1

3.7

46.8

5.0

32.5

2.5

168.9

3.6

223.2

9.4

97.2

10.5

98.7

7.4

418.9

9.1

696.1 371.6 310.8

29.3 16.6 13.1

285 89.4

30.7 9.6

195.6 614.6 8.3

14.8 46.4 0.6

1176.8 986.2 408.5

25.4 21.3 8.8

20.5 -

0.9 -

14.5

1.6

4.7 -

0.4 -

25.2 14.5

0.5 0.3

143.3

6.0

-

-

-

-

143.3

3.1

119.6 2376.5

5.0 100

927.4

100

1323.8

100

119.6 4627.7

2.6 100

51.4

20.0

28.6

CONCLUSION At the end of this investigation the species caught was generally low, this might be due to overexploitation of the fisheries resources in the lake as a result of influx of fishermen and the use of undersized mesh. Though castneting with corn bran recorded the highest number and weight of fish caught followed by castnetting without bait. It is therefore recommended for further study to be conducted in the lake using corn bran with other animal sources for inductive luring method, REFERENCES Ahmed, Y.B., A.B. Adimula and E.F. Agbontaen (2005). Study on the effects of three fishing baits on the catch composition of Malian traps in Lake Kainji. In: P.A. Araoye (ed) Processings of the 19th Annual Conference of the Fisheries Society of Nigeria, Ilorin, 29th November, - 3rd December 2004pp 557-562. Ahmed, Y.B; J.K. Ipinjolu and W.A. Hasssan (2006). Catch composition of gillnets and baited longilines in the southern basin of Lake Kainji , Nigeria. In: Ansa, E.J. et al. (eds) Processings of the 20th Annual National Conference of the Fisheries Society of Nigeria (FISON), Port-Harcourt, 14th – 18th November, 2005. Pp 350-360. du Feu, T.A. and J.A. Abiodun (1999). Fisheries Statistics of Kainji Lake, Northern Nigeria, November 1994 – December, 1998. Nigeria – German Kainji Lake Fisheries Promotion Project Technical Report Series 15. 128p.

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Y.B. Ahmed et al.,: Continental J. Fisheries and Aquatic Science 3: 37 - 41, 2009

FAO (1969). Fisheries survey in the Western and Mid-western region of Nigeria. United Nations Development Programme. FAO Rome. Hayes, D.B., C.P. Ferreri and W.W. Taylor (1996). Active fish Capture methods. In: B.R. Murphy and D.W. Willis (eds.) Fisheries Techniques, 2nd Edition, American Fisheries Society, Bethesda Marylan. Pp193220. Olaosebikan, B.D. and A. Raji (2004). Field Guide to Nigerian Freshwater Fishes. 2nd edition published by FCFFT, New Bussa, Unilorin Press, Ilorin-Nigeria. 111p Seisay, M.D.B. and T.A. du Feu (1997). The effect of long term exploitation by gillnet fishery on the multi-species fish stocks in Kainji Lake. NGKLFPP Technical report Series 11.58p. Solarin, B.B. and K. Kusemiju (2003). Fish Shelter as Fisheries Enhancement Techniques in Lagos Lagoon, Nigeria. Nigerian Journal of Fisheries 1(1): 57-61. SPSS (1999). Statistical Package for the Social Sciences SPSS for Windows release 10.0.1 Standard Version. Udolisa, R.E.K. and B.B. Solarin (1979). Design Characteristics of Castnets and Gillnets in Lagos Lagos Nigeria. NIOMR Occasional Paper Number 31, 24p. Udolisa, R.E.K; B.B. Solarin, P. Lebo and E.E. Ambrose (1994). A catalogue of small scale fishing gear in Nigeria . RAFR/014/F1/94/02:142P.

Received for Publication: 15/07 /2009 Accepted for Publication: 08/09 /2009 Corresponding Author: Y.B. Ahmed Federal College Of Freshwater Fisheries Technology,P.M.B. 1500, New Bussa, Niger State Email: [email protected]

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Continental J. Fisheries and Aquatic Science 3: 42 - 49, 2009 © Wilolud Online Journals, 2009. THE ROLE OF PROBIOTICS IN AQUACULTURE IN NIGERIA– A REVIEW Kolndadacha, O.D1., Adikwu, I.A2., Atiribom, R.Y1., Mohammed A1., Musa, Y.M1. and Ladu G.B1. 1 National Institute for Freshwater Fisheries Research, P.M.B. 6006, New Bussa, Niger State. 2 Department of Biological Science, Benue State University, Makurdi, Benue State ABSTRCT Aquaculture is beset by many problems especially diseases caused by bacteria as the major deteriorating factors. The use of vaccines and antimicrobial agents have been centered on disease control, but are associated with problems The development of antibiotic resistance among the microorganisms have become a global concern as a result of indiscriminate use of antibiotics. Several alternative suggestions for disease prevention have been on probiotics for its efficacy, low cost, less side effects and accessible to farmers. Probiotics is gaining a high priority in the developed countries with the aim of replacing conventional drugs. The principal bacterial groups tested as probiotic bacteria in culture of shrimps, crabs, oysters, fish and humans are Vibrio, Pseudomonas, Bacillus, Bifidobacteria and several Lactobacilli. Experiments have mainly been conducted with fish larvae, adult fish, crustaceans and animals where significant reduction in mortalities has been obtained. The purpose of this review is to create awareness of the role of probiotics in disease control in aquaculture as alternative to antibiotics. KEYWORDS: Role, Probiotics, Disease control, Aquaculture, Nigeria INTRODUCTION Aquaculture is concerned with the propagation and rearing of aquatic organisms under complete human control involving manipulation of at least one stage of an aquatic organism’s life before harvest in order to increase its production. This practice has become an important economic activity in many countries. In large-scale production facilities where aquatic animals are exposed to stressful conditions, problems related to diseases and deterioration of environmental condition often occur and result in serious economic losses. Prevention and control of diseases through the use of antibiotics and vaccines have been in practice in many countries of the world. However the utility of antimicrobial agents as a preventive measure has been questioned, given extensive documentation of the evaluation of antimicrobial resistance among pathogenic bacteria. The problems from the use of antibiotics have attracted a global concern in terms of development of resistance among the pathogenic bacteria. Resistance mechanisms of bacteria can arise in one of two ways: chromosomal mutation or acquisition R – plasmid. There is therefore an urgent need in aquaculture development for microbial control strategies since disease outbreaks are recognized as important constraints to aquaculture and despite the fact that the development of antibiotic resistance has became a matter of growing concern. One alternative to antibiotics in disease control in aquaculture could be the use of probiotic bacteria. The use of probiotics or beneficial bacteria which control pathogen through a variety of mechanisms is increasingly viewed as an alternative to antibiotic treatment. The use of probiotics in human (Anukam, et al., 2004, 2006 and Anukam, 2007) in animal nutrition (Fuller, 1992) are well documented and recently they have begun to be applied in aquaculture (Gatesoupe, 1999; Gomez-Gill et al.; 2000, Veschuere et al., 2000, Irianto and Austin, 2002). POTENTIAL PROBIOTIC BACTERIA IN USE Probiotics are harmless bacteria that help the wellbeing of the host animal and contribute directly or indirectly to protect the host animal against harmful bacterial pathogens. A review indicates a considerable potential of certain harmless bacterial strains to prevent or control fish diseases caused by pathogenic bacteria as well as boosting growth performance in farmed fish (Ashraf, 2000). It is assumed that uncontrolled development of the microbial communities in hatcheries is one of the major reasons for the unpredictable and often variable results; the introduction of microbial control practices by means of Probiotics may have a beneficial effect on the cultures in the hatcheries. Griffith (1995) reported that following the introduction of Probiotics in Ecuador in 1992, hatchery down-

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Kolndadacha, O.D et al.,: Continental J. Fisheries and Aquatic Science 3: 42 - 49, 2009

times between batches was reduced from 7days per month to 21 days annually, production volume increased by 35% and over all antimicrobial use decreased by 95%. In agriculture the value of probiotics notably Gram-positive bacteria such as lactobacillus has come to be appreciated as an alternative to antibiotics in disease control. A wide variety of micro-organisms have been found capable of producing substances which are inhibitory to other organisms. Other organism e.g. Pseudomonas are also known to be a natural competitor to other organisms like saprolegnia (Bly, et. al. 1997). These organisms that have the ability to compete, produce substance that stimulate the growth of other organisms or inhibit the growth of another are probiont and in future may be utilized for biological control in aquaculture as in mammalian probiotics. It is there for important to consider those bacteria that have antagonistic effect and those bacteria that stimulate the growth of others as important as potentials for probiotics in aquaculture. Einar (2002) reported that the most promising organisms for probiotic are Vibrio and Pseudomonas for fish and Bacillus for shrimp systems. Bergh (1995) added that the isolates that inhibit the growth of other bacteria belong to Pseudomonas /Alteromonas group, and the ability to produce compound that inhibit the growth of other bacteria may be wide spread among marine and fresh water bacteria. Austin et al. (1995) reported that a strain of V. alginolyticus was effective in reducing disease caused by Aeromonas salmonicida and 2 pathogenic Vibrio species. The table below summarizes the common probiont employed in culture of different aquatic organisms according to Gomez-Gill et al. (2000)

Table 1: Probiotics employed in culture of aquatic organisms Species of bacteria Target organism Reference Vibrio alginolyticus Shrimp (Panaeus vannamei) (Garriques and Arevalo, 1995) Thalassobacter utilis (PM-4) Shrimp (P. monodon) Maeda and Liao, 1991) V. harveyi, Pseudomonas sp., Shrimp (P. monodon and P. penicillatus) (Anonymus, 1991) Nitrobacter sp Nitrosomonas sp., and Bacillus sp. T. utilis (PM-4) Crab (Portumus trituberculatus) ( Nogami and Maeda, 1992, Nagomi, et.al. 1997) V. Pelagius Turbot (Scophthalmus maximus) (Ringo and Vadstein, 1998) Bacillus toyoi and B. sp. spore Turbot via rotifers (Branchionus plicatilis) ( Gatesoupe, 1989, ) Lactic bacteria Turbot via rotifers (Gatesoupe, 1990) Lactobacillus plantarum and L. helveticus Turbot via rotifers (Gatesoupe, 1991) Lacobcillus bulgaricus and Streptococcus lactis Turbot via Artemia (Douillet and Langdon, 1994) Aleromonas sp. Oyest (Crossotrea gigers) (Douillet and Langdon, 1994) Aeromonas media Oyster (Gibson, et.al. 1998) Rosebacter sp (NS107) Scallop (Pecten maximus) (Ruiz-Ponte, et.al, 1999) Vibrio sp Chalean scallop (Argopecten purpuratus) (Riquelme et.al, 1997) Source: Gomez- Gill et al. 2000 The highly researched and most used probiotics according to Berger (2002), are Lacobacillus acdophillus, L. bulgericus,Bifidobacteria longum and B.infantis Some of the commercial probiotics currently available in use include Aqualact, probela, Lacto-sacc Epicin, Biogreen, Environ, Wunopuo-15 and Epizyme (Abidi, 2003). However evidences indicate that probiotic effects are strain-specific, therefore a beneficial effect attributed to one strain cannot be assumed by another strain, even when they belong to the same species (Senok, et.al. 2005). Table 2 shows the probiotic bacteria used in aquaculture fishes.

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Kolndadacha, O.D et al.,: Continental J. Fisheries and Aquatic Science 3: 42 - 49, 2009

Table 2: Probiotics considered as biological control agents in aquaculture of fishes Probiotic strain Source Used on Method of application Streptococcus lactis and ? Turbot larvae Enrichment of live food Lactobacillu bulgaricus (Scophthalmus maximus) Lactobacillus sp. and Rotifers (Brachionus Turbot larvae enrichment of rotifers Carnobacterium sp. plicatilis) Vibrio alinolyticus commercial shrimp Atlantic salmon Bathing in bacterial Hatchery (Salmosalar) suspension Carnobacterium divergens Intestine of Atlantic cod fry Addition diet Alantic salmon Bacillus megaterium commercial product Channel catfish Additid to pond water B. subtilis, B. polymyxa (Biostart) B. lachenformis Vibrio pelagius Turbot larvae Turbot Addition to culture water Pseudomonas fluorscens Iced freshwater fish Rainbow trout Addition to culture water (Lates niloticus) (Oncorhynchus mykiss) Lactobacillus rhamnosus culture collection Rainbow trout Addition to diet Aeromonas hydrphila Digestive tract of Rainbow trout Addition to diet rainbow trout Bacillus circulans Intestine of L. rotifer Addition to diet Labeo rotifer

Reference Garcia de la Blanda et al. (1992) Gatesoupe, et al. (1995) Austin, et al. (1992) Gibson et al. (1998) Queeirz and Boyd (1998)

Ringo and Vadstein (1998) Gram et al. (1999) Nikoskelainen et al. (2001) Irianto and Austin, (2002) Gomez-Gil, et al. (2000)

Source: Balcazar et al. (2006) APPLICATION OF PROBIOTICS IN AQUACULTURE These organisms can be administered to the aquaculture organisms through feeding, injection or immersion of the probiotic bacteria (Irianto and Austin, 2002). Application in Feed Probiotics are applied with the feed and a binder (egg or cod liver oil) and most commercial preparation contain either Lactobacillus sp or Sacharomyces cerevisiae (Abidi, 2003). Regular use of probiotic in feed of fish in U.K. and other European countries has been reported to have several health benefits (Cerrato 2000). The perception that fermented milk yoghurt is beneficial is already wide spreading within so many regions because, traditionally these products have been used by local healers for the treatment of diverse condition, such as skin, allergies, stomach upset especially diarrhea and vaginal discharges. According to FAO and WHO guidelines, probiotic organisms used in food must be capable of surviving passages through the gut i.e. they must have the ability to resist gastric juices and exposure to bile (Senok et al 2005). Further more they must be able to proliferate and colonize the digestive tract and they must be safe, effective and maintain their effectiveness and potency for the duration of the shelf life of the product (Senok et al, 2005). Dairy products including yoghurt, fermented milk product and cheese remain at forefront of probiotic food development in humans. Yoghurt with added live probiotic strains is now available commercially and a number of such products have emerged as leaders in the European market are now also available internationally. In aquaculture probiotic can also be encapsulated in feed (Einar 2002) or through live food like rotifers and artemia Another efficient application of probiotics to aquatic animal according to Einar (2002) is via bio-encapsulation or infusions in diets. Preparation of probiotic diet has been demonstrated by Yassir et al, (2002). Direct to Culture Water/ Pond The water probioics contain multiple strains of bacteria like Bacillus acidophilus, B. subtilis B. lecheniformis, Nitrobacter sp, Aerobacter and Sacharomyces cerevisiae. Application of probiotic through water of tanks and ponds may also have an effect on fish health by improving several qualities of water, since they modify the bacteria

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composition of the water and sediments (Ashraf, 2000; Venkateswara, 2007). When probiotics are applied in culture water they multiply and over grow the pathogenic organism present in the water. Beside this Venkateswara (2007) reported that probiotic bacteria are generally called bacteria which can improve the water quality of aquaculture and inhibit the pathogens in water thereby increasing production. Today many researchers attempt to use some kind of probiotic in aquaculture water to regulate the microflora of aquaculture water, control pathogenic microorganism to enhance decomposition of undesirable organic substances in the water and improve ecological environment of aquaculture (Xiang-Hong et. al;2000 Venkateswara ,2000). Einar (2002) identified some ways of using probiotcs either as larval food or enriched brachionus or artemia with probioics. Application through Injection Application of probiotics by injection is a possibility. Austin, et al. (1995) suggested the possibility of freeze-drying the probiont like vaccine and applied either through bathing, or injection. Except for experimental purposes application of probiotic by injection has not been widely reported. Even though one of the benefits of probiotics in fish and animal is to boost the immunity, meaning that there is the stimulation of antibodies of the host. Probiotics can therefore confer the best immunity through injection as Lamar (1985) reported that injection the best method of vaccination. However (Gram et al (1999) state that vaccination by injection which some times the only effective route of administration is impracticable when applied to small fish or larger numbers. Yassir et. al. (2002) has demonstrated the experimental administration of probiotic Micrococcus luteus to Oreochrmis niloticus by injection through intra peritoneal route which had only 25% mortality as against 90% with Pseudomonas using the same route. According to Yassir et al (2002) the use of probiotics stimulate Rainbow trout immunity by stimulating phagocytes activity, complement mediated bacterial killing and immunoglobulin production (Nikoselainen et al, 2003). When probiotics is evaluated in freeze dried form, it can be applied through injection BENEFITS OF PROBIOTICS Although some of the effects of probiotics have been documented clearly, research is still on going in the area with so many questions on the reality of some of the benefit remaining unanswered. However it is crucial to remember that different probiotic strains are associated with different health benefits (Senok et al.2005). Improvement in Water Qualities According to Venkateswara (2007), probiotics have been reported to regulate micro flora, control pathogenic ones, enhances the decomposition of the undesirable organic substance, improve ecological environment by minimizing the toxic gasses like NH3, N20, H2O2, Methane etc, increases population of food organism in the water, increases nutritional level of the aquatic host and improve their immunity in the culture water. In several studies, improved water quality has been recorded during the addition of the probiotics especially with Bacillus sp. (Verschuere et al, 2000). The rationale is that Gram-positive Bacillus sp. are generally more effective in converting organic matter back to CO2 than G-negative bacteria which could convert a greater percentage of organic carbon to bacterial biomass or slime. As Growth Promoters One of the activities of probiotic bacteria is expected to have a direct growth promoting effect of fish either by direct involvement in nutrient uptake or by providing nutrient or vitamin. However, it has been demonstrated experimentally that probiotics indeed may enhance the growth of fish. The ability of organisms to out-grow the pathogens in favor of host or to improve the growth of the host and yet no side effect on the host made it a probiotic bacteria. Yassir et al. (2002) in attempt to use probiotic bacteria as growth promoter on tilapia (Oreochromis niloticus) identified that the highest growth performance was recorded with Micrococcus luteus a probiotic and the best feed conversion ratio was observed with the same organism. So M. luteus may be considered as a growth promoters in fish aquaculture. Lactic acid bacteria also had an effect as growth promoters on the growth rate in juvenile carp though not in Sea bass (Noh et al, 1994). Also Enterococcus facium had been used to improve growth when applied in feed to fish (Bogut et al. 2000). Irianto and Austin (2002) reported that probiotics may stimulate appetite and improve nutrition by producing vitamins, detoxification of compounds in the diet and by the breakdown

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of indigestible components. Streptococcus facium improved the growth and feed efficiency of Israeli carp (Noh et al. 1994). Probiotics therefore can be regarded as growth promoters in aquaculture organisms in addition to various benefits of probiotics. For Good Health Many probiotic products are used routinely by healthy individuals indeed the marketing of many probiotics food probiotics is targeted at healthy individuals. The claim that regular ingestion will contribute to a healthy life style, promote general wellbeing and protect against or reduce the risk of developing chronic gastrointestinal, respiratory or cardiac problems in the long term has induced many people to undertake regular consumption of these products. (Senok, et.al., 2005). Selected probiotics have shown to have significant health benefits for humans and thus several well-characterized strains are available for human use to reduce the risk of gastrointestinal infection or to treat such infection (Nikoskelainen, 2001). In countries of continental Europe, probiotics are regarded as medicine and they are prescribed alongside antibiotics, while in other countries probiotics are marketed as supplement and are sold over the counter (Berger, 2002) for good health. For Disease Prevention Probiotics or their products for health benefits to the host have been found useful in aquaculture, terrestrial animals and in human disease control. These include microbial adjunct that prevent pathogens from proliferating in the intestinal tract, on the superficial surfaces and in culture environment of the culture species (Verschuere, et.al. 2000). The effect of these beneficial organisms is achieved through optimizing the immune system of culture organism, increasing their resistance to disease, or producing inhibitory-substance that prevent the pathogenic organisms from establishing disease in the host. Culture System, Inc, (2002) added that good bacteria in the gut aid in many important function such as nutrient digestion, immune function and prevention of pathogens. One of the well established benefits of probiotics is the decrease in occurrence and duration of diarrhea especially those caused by antibiotics like ampicillin using mixture of L. bulgericus, L.acidophillus ,Bifidobacterium and Streptococcus bacteria. This is also true for the use of L. rhamnosus GG, L. reuteri SD2222 and B. lactis BB-12 in the prevention and treatment rotavirus diarrhea in children, cited by Senok et.al (2005). However probiotics is becoming a popular treatment for the occurrence of urogenital infection in the women. Several studies suggest that the administration of Lactobacillus either orally or intravaginally is an effective treatment and preventive measures against urogenital infection (Geldzwis, 2007 and Senok, et al. 2005). Some authors conducted studies in animals showed that probiotics may be a protective factor against cancer of colon, prostate, bladder and other cancer, because probiotic bacteria protect carcinogenic activities and L. acidophilus or L. casei are reported to play this role. Therefore the use of probiotics have a potential benefits for conditions such as gastrointestinal infection, genitourinary infection, allergies and certain bowel disorders all which afflict a considerable proportion of the global population (Senok et al. 2005). SELECTION CRITERIA FOR PROBIOTICS The initial major purpose of using probiotics is to maintain or re-establish a favorable relationship between friendly and pathogenic microorganism that constitute the flora of intestinal or skin mucus of fish. A successful probiotic is expected to have a few specific properties in order to certify, a beneficial effect. FAO/WHO (2001) guidelines recommend that in the cause of selecting probiotics, the probiont should be evaluated for a number of parameters such as, antibiotic susceptibility patterns, toxic production, metabolic and hemolytic activities, infectivity in immuno-compromised host and side-effects Characteristics of Good Probiotics Filler (1989) listed the following as features of good probiotic bacteria.
Its should be a strain, which is capable of exerting a beneficial effect on the host animal e.g. increased growth or resistance to disease
It should be non-pathogenic and non-toxic
It should be present as viable cells preferable in large numbers
It should be capable of surviving and metabolizing in the gut environment e.g. resistance to low pH and organic acid.

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It should be stable and capable of remaining viable for periods under storage and field conditions.

A probiotic agent with all these features has considerable advantage over antibacterial supplements such as antibiotics currently in use. They do not induce resistance to antibiotics which will compromise therapy. They are not toxic and therefore will not produce undesirable side effect when being feed and in the case of food animal will not produce toxic residues in the carcass. They may stimulate immunity whereas the immune status remains unaffected by antibiotics. An essential determinant in the choice of a probiotic microorganism is its ability to reach, survive and persist in the environments (Charles et al. 1998). CONCLUSION Probiotics as an alternative to antibiotics in aquaculture becomes imperative. The most highly researched probiotic bacteria today are Lactobacillus acidophilus, L. bulgarium , Bifidobacteria longum, and B. infantis REFERENCES Abidi, R. (2003). Use of probiotics in larval rearing of mew candidate species. Aquaculture Asia April-June 2003 vol. Viii No.2 Pp15-16 Anonymous (1991). Disease control in hatchery by microbiological techniques. Asian shrimp News 8:4, 4th quarter Anukam, K.C. (2007).The potential role of probiotics in reducing poverty associated infections in developing countries. International journalof probiotics and prebiotics 1 (2): 81-83 Anukam, K.C., Osazuwa, E.O. and Reid, G. (2006). Knowledge of probiotics by Nigerian clinicians. International journal of probiotics and prebiotics 1(1): 57-62 Anukam, K.C., Osazuwa, E.O. and Reid, G. (2004). Reducing the risk of HIV in women, using probiotics as an alternative strategy. International conference on AIDS 2004 July 11-16, 15: Abstract no. E. 10839 Ashraf, Ali (2000). Probiotics in fish farming – Evaluation of a candidate bacterial mixture. Vattenbruksinstitutionen . Report 19, Umea’2000, Ph. Licentiate Thesis. Pp 1-18 Austin, B., Baudet, E. and Stobie, M. (1992). Inhibition of bacteria fish pathogens by Tetraselmis suecica Journal of Fish Diseases, 15: 53- 61 Austin, B., Stukey, L.F., Robertton, P.A., Effendi, I. and Griffith, D.R.W. (1995). A probiotic starian of vibrio alginolyticus effective in reducing disease caused by Aeromonas Salmonicida. Vibrio anguillarum and Vibrio ordali. Journal of Fish Diseases, 18: 93- 96 Balcazar, L. J., Blas, I., Ruiz-Zarzuela, I., Cunningham D., Vendrell, D. and Muzquiz, L.J. (2006). The role of probiotics in aquaculture. Veterinary Microbiology 114:173-186 Bergh, Q. (1995). Bacteria associated with early stages of Halibut Hippoglossus hippoglossus L., inhibit growth of a pathogenic Vibrio.sp. Journal of Fish Disease 18: 31-40 Berger, A. (2002). Probiotics. British Medical Journal, 224 (7350): 1364, Online Bly, J.E., Quindou, S.M.A., Lawson, L. A. and Chem, L.W. (1997). Inhibition of Saprolegnia pathogenic for fish by Pseudomonas fluorescents. Journal of Fish Disease 20:35-40 Douillet, P.A., and Langdon, C.J. (1993). Effect of marine bacteria on the culture of axenic oysters Crassostrea gigas, Thurberg larvae. Biological Bulletin 184:36-51 Douillet, P.A. and Langdon, C.J. (1994). Use of probiotics for the culture of larvae of the pacific oysters Crassostrea

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gigas, Thurberg. Aquaculture 119:25-40 Fuller, R. (1992). History and development of probiotics. In: Fuller, R.D. (Ed). Probiotics: the scientific bases. Chayoman and Hall, New York, Pp1-8 International conference on AIDS 2004 July 11-16; 15 : Abstract no. E. 10839 Garcia-de-la-Banda, I., Chereguini, O. and Rasnes, I.(1992). Influence of lactic bacteria additives on turbot ( Scophthalmus maximus L.) larvae culture. Bol. Inst. Esp. Oceanogr. 8:247-254 Garriques, D., and Arevalo, G. (1995). An evaluation of the probiotics and the use of a live bacterial isolates to manipulate the microbial flora in the commercial production of Panaeus vannzamei post larvae in Ecuador, C.L. and Hopkins, J.S.(Eds). World Aquaculture Society. Pp 53-59 Gatesoupe, F.J. (1999). The use of probiotic in Aquaculture. Aquaculture 180:147-165 Gatesoupe, F.J. (1990). The continuous feeding of turbot larvae Scopthalmus maximus and control of the bacterial environment of rotifers. Aquaculture 89:139-148 Gatesoupe, F.J. (1989). Further advances in the nutritional and antibacterial treatment of rotifers as food for turbot larvae Scopthalmus maximus L. In: de- Pauw, N. (Ed), Aquaculture- a Biotechnology in progress. European Aquaculture Society Bredene. Pp 721-730 Geslewitz, G., (2007). Probiotics: New Strains amid gowing pains. Vitamins retailer, http://www.vitamins retailer. Com/VR/articles proboitics.htm P8. Gibson, L.F., Woodworth, J. and George, A.M. (1998). Probiotic activity of Aeromonas media on the pacific oyster, Crassostrea gigas, when challenged with Vibrio tubiashi. Aquaculture 169: 111-120 Gomez-gill, B., Roque, A. Turnbell, J.F (2000). The use and selection of robiotic bacteria for use in the culture of larval aquatic organisms. Aqualcuture 19: 259-270. Gram, L. Melchiorison, J., Spanggerard, B., Hubber, I. and Nielsen,. T. F. (1999). Inhibition of Vibrio anguilarum by Pseudomonas fluerescens A H2 G possible probiotic peatiment of fisg. Applied Environmental Microbiology, 65:969-973. Griffith, D.R.W. (1995). Microbiology and the role of probiotics in Ecuadorian shrimps hatcheries. In: Larens P. Jaspers, E. Roelands I. (Eds) posium. European aquaculture society Gent, P. 478. Special Publication No.24. Irianto, A. and Austin, B. (2002). Probiotics in aquaculture. Journal of Fish Disease 25:633-642 Maeda, M., and Liao, I.C. (1992). Effect of bacterial population on the growth of a prawn larvae Panaeus monodon. Aquaculture 21:25-29 Nogami, K. and Maeda, M. (1992). Bacterial as biocontrol agent for rearing larvae of the crab Portunus trituberculatus. Canadian Journal of Fisheries and Aquatic Sciences, 4.9: 2373-2376 Nogami, K., Hamasaki, K., Maeda, M. and Hirayama, K. (1997). Biocontrol method in aquaculture for rearing the swimming crab larvae Portunus tritiberculatus. Hydrobiologia, 358:291-295 Okaeme A.N., Mohammed A. Adbulrahman and M. Kolndadacha, O.D (2003).probiotics research as alternative strategy in the control of bacterial disease in fish production. Peer reviewer. Proceeding of 16th Annual Congress of Biotechnology Society of Nigeria pp.139-142.

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Queiroz, J. F. and Boyd, C.E. Effect of a bacterial inoculums in channel catfish ponds. Journal of WorldAquaculture Society. 29:67-73 Seniok A.C.ismeel A.Y.Botta G.A, (2005). Pprobiotics: facts and myths. Clinical Microbiology andInfection Diseases 11:958-960 Ruiz-Ponte, C., Samain, J.F., Sanchez, J.L., and Nicolas, J.L. (1999). Thre benefit of a Roseobacter species on the survival of Scallop larvae. Marine Biotechnology, 1: 52-59 Ringo, and Vadstein, O. (1998). Colonization of Vibrio Pelagius and Aeromonas caviae in early developing turbot Scophthalmus maximus(L) larvae. Journal of Applied Microbiology. 84:227-233 Riquelme, C., Araya, R., Vergara, N., Rojas, A., Guita, M. and Candia, M. (1997). Potential probiotic strains in the culture of the Chilean Scollap Argopecten purpuratus (Lamarck 1819). Aquaculture 154: 17-26 Tanock, G. W. (1997). Modification of the normal of the normal microbiota by diet, sress, antimicrobial agents and probiotics. In : Mackie R. I. with B.A. Isaacson R.E. (ed), Gastrointestinal Micrbiology vol 2, Gastrointestinal Micobes and host interaction. Chapman and Hall Microbiology Series, International Thampson Publishing, New York, Pp 434- 465 Venkateswara, A. R.(2007). Bioremediation to restore the health of aquaculture. Pond Ecosystem. Hyderabad – 500 082, India. Pp 1-12 Verschuere, L., Romout, G., Sorgeloos, P. and Verstrate, W. (2000). Probiotic bacteria as Biologcal control agents in aquaculture. Microbiology and Molecular Biology Reveiws, 64(4): 65-671. Xiang-Hong, W., Jun, L., Wei-shang, J. Huai-shu, X. (2003). Application of probiotics in aquaculture. Ocean Universityof Qungo, China. Online pp1-10 Yassir, A.L. Adel, M.E. and Azze, A. (2002). Use of probiology bacteria as growth promoters, antibacterial and the effect on physiological parameters of Oreochronus niroticus. Journal of Fish Diseases 25: 633-642 Received for Publication: 15/07 /2009 Accepted for Publication: 08/09 /2009 Corresponding Author: Kolndadacha, O.D National Institute for Freshwater Fisheries Research, P.M.B. 6006, New Bussa, Niger State

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