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The study examined the feasibility of a small scale integrated fish cum poultry farming project utilizing concrete tank of 4 x 4.8x3.5m. 900 post fingerlings of Clarias gariepinus (52 2.7g) were stocked in 3 concrete tanks at the rate of 1fish per 5m2 and fed diets containing 38% (Diet 1). 33% (Diet 2) and 31% (Diet 3) crude protein levels. Three battery cages containing 15 laying birds were installed on each tank. The birds were fed with layer mash (CP 18%) while the fish were fed with 300kg of fresh maggots and pelleted feed. At the end of 213days, growth response and nutrient utilization of fish were based on Average daily weight gain, (DWG 4.48) relative growth rate (RGR 1834.27) and specific growth rate (SGR 1.39). Final weight ranged from 949.2g to 963.2g. Daily weight ranged from 4.46g to 4.52g. Feed cost for fish was drastically reduced while revenue from poultry was significantly increased. The profitability analysis of the operation showed that table size Charias production generated return to investment of 31.19%, a rate of return on fixed cost 163.79% and a rate of return on variable cost of (161.07). The financial analysis reveals a viable investment.

Pineapple crush waste (PCW) was used to replace maize as an energy source in the diets of Tilapia, Oreochromis niloticus. Five diets (31.52-32.51% crude protein) was formulated in which yellow maize was replaced at varying level with pineapple waste as follows: Diet 1 (100% yellow maize), diet 2 (75% yellow maize, 25% PCW), diet 3 (50% yello maize, 50% PCW), diet 4 (25% yellow maize, 75% PCW), diet 5 (100%PCW). Growth performance of fish was highest in diet 4 for all investigated growth parameters such as average daily growth (0.73g), final body weight (76.21g) and protein efficiency ratio (2.02). differences in FCR and PER were not significantly different between all diets. Diet with 100% PCW had the least growth performance. Results from the study showed that PCW was better utilized by Tilapia fish when the level of its replacement was either equal or slightly higher than that of yellow maize. Tilapia fish did not thrive well when the maize in practical diets was replaced completely with PCW.

Fish is a major source of protein in human diets. Fish demand has been on the increase due to increase in human population which has resulted to wide gap between fish demand and supply. This study was carried out to elucidate the major fish species that are economically important in the study area. Assessment of fish catch composition was done in the marine artisanal fish sector of Southwest Nigeria Gulf of Guinea. The study area was divided into three strata with one sampling station selected from each stratum. Four canoes were sampled per site per month. Fish catches were sorted into taxonomic categories, counted, measured and weighed. Sixty-nine fish species from forty-two families were identified constituting fifty-nine finfish and ten shellfish species. Clupeid family had the highest contribution both by weight (40.5%) and abundance (53.7%). Sardinella maderensis was the most abundant species by number (30.6%) and weight (27.9%). Parapenaeopsis atlanticus (51%) was the most abundant shellfish while P. validus (87%) was the highest by weight. Fish production was highest in Station 1 both by weight (37%) and abundance (41%). The status of finfish species showed that five species were very common; four were common, fourteen uncommon and thirty-six rare. Among the shellfish species, three species were very common, none was common, three were uncommon and three species rare. Effective management of these fish resources is necessary to ensure fish food security. Key words : Artisanal fishery, Gulf of Guinea, species, abundance, Southwest, Nigeria.

A study was conducted to evaluate the effect of black soldier fly (Hermetia illucens) larval meal (BSF) in practical diets of African catfish (Clarias gariepinus). Four diets were formulated to contain levels of fishmeal replacement at 0, 25, 50, and 100% with BSF. A total of 360 fingerlings (2.67 ± 0.0 g/fish) were randomly distributed into 12 tanks (30‐L capacity) containing 30 fish each and fed with the respective diet to apparent satiation. After 6 weeks of feeding, growth performance and nutrient utilization indices of the groups fed 25 and 50% BSF diets were not significantly different (p > .05) from the group fed the fishmeal‐based control diet. However, further increase in the replacement of fishmeal with BSF (100%) led to a significant (p .05) compared with the control group. From the current study, it was clear that fishmeal could be replaced with BSF up to 50% without affecting the growth performance, nutrient utilization, survival, and welfare of C. gariepinus fingerlings.

Studija ocjenjuje usvajanje poboljšanih tehnologija akvakulture među uzgajivačima ribe u Lagosu u Nigeriji. Ukupno 90 uzgajivača ribe uzorkovano je kroz višestupanjske tehnike uzorkovanja. Validirani i predtestirani raspored intervjua je korišten za dobivanje primarnih informacija od uzgajivača ribe. Dobiveni podaci obrađeni su deskriptivnom i inferencijalnom statistikom. Dobiveni rezultati pokazuju da je više od pola uzgajivača ribe dobilo kreditne pogodnosti od kooperativnih društava te oko jedne trećine od Esusa, dok su gotovo svi prodavali svoje ribe kao dimljene. Veći udio uzgajivača ribe su bili svjesni, pokušali su i usvojili većinu poboljšanih tehnologija akvakulture, dok su neki uzgajivači ribe obustavili većinu ranije usvojenih tehnologija. Ova studija također ukazuje da su uzgajivači riba imali pozitivan stav prema usvajanju poboljšanih tehnologija akvakulture. Rezultati regresijske analize su pokazali da su sekundarno zanimanje uzgajivača ribe (β = -0,324, p, The study assessed the adoption of improved aquaculture technologies among fish farmers in Lagos State, Nigeria. A total of 90 fish farmers were sampled through the multistage sampling technique. A validated and pretested interview schedule was used to obtain primary information from the fish farmers. Obtained data were analyzed using descriptive and inferential statistics. Results obtained revealed that more than half and about one-third of the fish farmers sourced credit facilities from cooperative societies and Esusu, respectively, while almost all sold their fishes as smoked fish. Higher proportions of the fish farmers were aware, tried and adopted most of the improved aquaculture technologies with some of the fish farmers also discontinuing most of the previously adopted technologies. The findings of the study also reported that the fish farmers had positive attitude towards the adoption of improved aquaculture technologies. Results of regression analysis revealed that secondary occupation of the fish farmers (β=-0.324, p

A feeding trial was conducted to evaluate the effects of replacing fish meal (FM) with bacterial protein (BP) in African catfish (Clarias gariepinus) diets. Four iso‑nitrogenous (369 g kg−1) and isolipidic (142 g kg−1) diets were formulated to replace graded levels (0%, 30%, 60% and 100%) of FM protein resulting in a dietary inclusion level of 0, 27.90, 55.70 and 93.00 g kg−1 BP. Test diets were fed to the catfish (initial weight 18.17 ± 0.25 g fish−1, n = 20) in three replicate tanks. After 56 days of feeding, catfish fed with 30% BP diet had outperformed (P 0.05). While histological analysis of the catfish mid-intestine showed intact epithelial barriers with extensive mucosal folds extending into the lumen. The intestinal perimeter ratio of fish fed with 30% BP diet was higher (+32%) than those of the dietary control group (P 0.05). Indication of the liver health status was measured through serum aspartate transaminase, alanine transaminase, and alkaline phosphatase activities, and hepatocyte density, which remains statistically unchanged between the dietary groups (P > 0.05). Overall, the results show that BP can replace FM wholly or partly in African catfish (C. gariepinus) diet, without compromising growth performance, haemato-biochemistry, intestinal integrity, or liver functionality.

Environmental parameters and ichthyofauna were investigated over a 2 years period in three regions along the 200 km length of Cross River. The objective of the study was to quantify the relative importance of local environmental conditions prevailing within sampling sites and the composition and abundance of the principal fish species in the upper, middle and lower reaches of the river. Vegetation cover, size of river, flow velocity, water level, temperature, transparency, and food availability explained the observed seasonal and spatial changes in fish abundance. Forty-six species and 28 genera of fish belonging to 16 families were recorded among the 14,466 fish caught. Three fish families (Cichlidae, Bagridae, and Clariidae) yielded highest number (41.3%) of species while Denticeptidae, Protopteridae, and Osteoglossidae had the least. Oreochromis niloticus, Chrysichthys nigrodigitatus, and Clarias anguillaris numerically dominated (46.4%) catch composition. Species richness was higher for the river stretch in forest area than in savanna, and it was correlated significantly with width of the reach, water transparency, depth, and flow velocity (P 0.6) and had higher richness (>9.7) than those for dry season. Wet season and forest regions were therefore critical in maintaining fish stock of Cross River.

The multivariate relationship between fish species and environmental variables was studied at three landing sites along the coast of the Gulf of Guinea, Southwest Nigeria. Fish species were sampled for abundance once per month per site for twenty-four months and eight environmental variables were measured. Five fish species (Sardinella maderensis, Ilisha africana, Pentanemus quinquarius, Chloroscombrus chrysurus, Ethmalosa fimbrata and Pterioscion peli) were observed to be very abundant, which contributed 77.6% of the total abundance. Fish species composition depicted tropical waters fishery with few dominant species having large number of individuals. Dendogram of cluster analysis revealed five fish communities. Canonical correspondence analysis was used to elucidate the relationships between assemblages of fish species and their environment. S. maderensis, the most abundant species, was observed to be influenced by pH, total dissolved solids (TDS) and nitrate. Clustering and ordination techniques provided very similar results based on the fish species composition. Water pH, total dissolved solids (TDS), nitrate and conductivity were shown to be most influencing environmental variables in decreasing order of vector projections, influencing fish assemblages in marine coastal waters of the Gulf of Guinea, Southwest, Nigeria., Ovim istraživanjem proučavan je multivarijatni odnos vrsta riba i varijabli iz okoline na tri mjesta duž obale Gvinejskog zaljeva u jugozapadnoj Nigeriji. Uzorci riba prikupljani su jednom mjesečno na odabranim lokacijama tijekom 24 mjeseca, pri čemu je mjereno i osam varijabli iz okoline. Najčešće vrste riba, sa 77,6 % udjela ukupne riblje populacije, bile su: Sardinella maderensis, Ilisha africana, Pentanemus quinquarius, Chloroscombrus chrysurus, Ethmalosa fimbrata i Pterioscion peli. Sastav ribljih vrsta prikazuje ulov u tropskim vodama s nekoliko dominantnih vrsta koje imaju veliki broj jedinki.. Dendrogram klaster analize prikazuje pet ribljih zajednica. Kanonička korelacijska analiza korištena je kako bi se razjasnio odnos između sastava vrsta riba i njihove okoline. Utvrđen je vidljiv utjecaj pH, ukupnih otopljenih tvari (TDS) i nitrata na S. maderensis, najbrojniju riblju vrstu. Tehnike grupiranja i koordinacije dale su vrlo slične rezultate temeljene na sastavu ribljih vrsta. pH vrijednost vode, ukupne otopljene tvari (TDS), nitrati i provodljivost najutjecajnije su varijable okoline u opadajućem redoslijedu vektorske projekcije, a znatno utječu na riblji sastav u moru na obalama Gvinejskog zaljeva u jugozapadnoj Nigeriji.

An investigative study was carried-out on management indicators and growth performance index of T. zillii in a tropical coastal estuary for twenty-four consecutive months using length-weight data. Electronic length frequency analysis (ELEFAN), sub-routine of FiSAT II software and empirical models were used to analyse the data. Results showed that the mean size of T. zillii was between 22.10±1.155 cm and 26.10±0.115 cm in April and January respectively. The highest (349.72±2.725g) and lowest (264.14±4.109g) mean weights were recorded in the respective months of December and April. Exploited sizes ranged from 11-12 cm to 36-37 cm. Length class 24-25 cm was mostly exploited, constituting 9.92% while 36-37 cm length class was the least (0.05 %) on the exploitation data. Length-at-first maturity, Lm, length-at-optimum yield, Lopt, longevity, Tmax, and growth performance index were estimated as 10.23 cm, 23.95 cm, 4 years and 3.076 respectively. It was therefore, recommended that, for the fishery to be sustainable, close monitoring should be given during the months of February and April, and exploitation of larger size fish be regulated to prevent recruitment overfishing.

As coastal populations in Africa continue to grow and pressures on the environment from land-based and marine human activities increase, coastal and marine living resources and their habitats are being lost or damaged in ways that are both decreasing livelihood opportunities and aggravating poverty. Coasts are experiencing the adverse consequences of hazards related to climate and sea level. While physical exposure can significantly influence vulnerability for both human populations and natural systems, a lack of adaptive capacity is often the most important factor that creates a hotspot of human vulnerability. Nigeria’s Niger Delta is widely recognised for its rich and diverse biological resources and these natural systems form the foundation of the economy of the country, from which the majority of the population derive their livelihood. Threatened terrestrial and marine ecosystems translate to threatened livelihoods in Africa. In the Niger Delta of Nigeria exploitation of these non-living resources has damaged the coastal environment and has caused civil conflict. This paper presents the different categories of this system’s coastal resources and highlights the different methods of exploitation and the consequences of these methods. The paper exposes the different challenges of this multi-functional ecosystem of Africa’s most populous country, which also ranks fourth in the world oil producer’s list. It concludes by suggesting various ways of managing this oil-rich environment.

Studies were conducted on the growth and mortality parameters, recruitment pattern, probability of capture, yield-per recruit, and present rate of exploitation of the African river prawn, Macrobrachium vollenhovenii from Dawhenya impoundment, Ghana. Estimation of the von Bertalanffy growth parameters gave; L∞ = 14.2 cm, K = 1.0 yr -1 , and to = -0.195 yr -1 with the growth performance index, Ф' of 2.303. From the linearised length-converted catch curve, total mortality, Z was 5.36 yr -1 . Natural mortality, M calculated from Pauly’s empirical formula was 2.20 yr -1 and fishing mortality, F calculated from Z - M was 3.16 yr -1 . From the mortality estimations, the present rate of exploitation, E calculated from F/Z was 0.59 indicating that, the species is on the verge of being over-exploited in the impoundment. Using the estimated value of the growth coefficient, K, the longevity was found to be about 3 yrs. Estimations from the probability of capture routines gave the length-at-first capture, Lc as 3.07 cm while the size distribution of the catches suggest two recruitment pulses in a year. It is therefore recommended that, the property right-based system for fisheries management should be implemented so that fishermen can cooperate in the management of the Macrobrachium fishery.

Some aspects of the chemical and anatomical weight composition of shrimps in Nigeria's Coastal Waters were analysed with a view to obtaining the flesh yield, waste yield and their utilization potentials. The four most abundant shrimp species in Nigeria's waters were selected for the study. Proximate analysis of the species [ Macrobrachium rosenbergii (freshwater); Palaemon serratus (brackishwater); Panaeus notialis and Parapenaeopsis atlantica (marine)] was carried out on the flesh, shell and head. The moisture content of the flesh varied from 71·57±0·33% in Palaemon serratus to 75·95±0·16% in Parapenaeopsis atlantica . The protein content varied between 26·30±0·34% and 22·35±0·30% in flesh of all the species. Fat content was generally low, ranging between 0·79±0·03% and 1·11±0·18%. Crude fibre was below 0·06% in the flesh of all the species. The concentrations of calcium, magnesium, potassium, sodium, phosphorus, manganese, copper, iron and zinc were determined in the head, shell and flesh of the four species. The head was consistently higher than the shell and flesh in the levels of the various elements. Anatomical fractionation showed the head was about 33% of the total weight while the head-off portion was about 66%. The total flesh yield obtainable from the shrimps was 51% and the waste yield was 49%. The possibility for processing shrimp waste into shrimp meal and single cell protein is discussed.

The ecology of sympatric African bony tongue fish, Heterotis niloticus and the catfish, Clarias gariepinus were compared during the dry and rainy conditions in the lower Oluwa River and its adjacent floodplains. Both species are common economic fish in Nigeria. There was no significant difference in the mean sizes of H. niloticus and C.gariepinus from the samples collected during the rainy season and the dry season. The river channels had the least number of the sampled species for both fish under study. Approximately 65% of the H. niloticus that were collected inhabited the Mahin floodplains while 74% of C. gariepinus were found in the same habitat. During the rainy season, most of the Heterotis caught were juveniles in the middle floodplains while juveniles of Clarias were caught in the upper floodplains. Phytoplankton accounted for over 62.53% of the total stomach contents of H.niloticus using the frequency of occurrence method, while fish parts constituted the highest percentage of components of C.gariepinus (16.62%). By volumetric method, plant materials formed the bulk of the 29.55% of food items observed in H.niloticus while fish parts also formed the highest portion of the diets (25.56%) in C.gariepinus . Fish population of both species were high in all the locations of the study area, however analysis of the preponderance of male to female during the two seasons of the year shows that there were more females to males during the rainy season for both species. Key words: ecology, Heterotis niloticus , Clarias gariepinus , Oluwa River, floodplains Ife Journal of Science Vol. 7(1) 2005: 15-20

This study was undertaken to investigate the relationship between poverty and the different fishers management practices being employed by fishermen in the exploitation and harnessing of the costal wetlands of Ondo State. Over 80% of the fisher-folks are by nature very poor and thus will more often than no `eat deep' into the fish resources at their disposal. The results of the study show that the most prevalent management practices were gillnetting, caste netting and seine-netting. These were found to be very versatile, durable and affordable. It reveals that those practices which posses the highest potentials for short-term income generation were more commonly used. The lowest direct cost of investment in engaging in any practice was in gill netting, while the highest was in the use of chemical and herbal poisons. The perceived ability of each practice to generate short-term income gains was highest for gill netting and followed by total draining. The least practice in the generation of short-term income gains was hooks and line, spears and closed season. The paper recommends among others the effective tackling of the poverty-related issues in the Nigeria's artisanal fishery sub-sector. [JEXT Vol.1(1) 2000: 54-62]

It has been considered that the impacts of climate change are likely to be considerable in tropical regions. Developing countries are generally considered more vulnerable to the effects of climate change than more developed countries. This has been attributed to a low capacity to adapt in the developing countries. Fisheries and aquaculture are threatened by changes in the earth atmosphere and ocean, such as increasing global surface temperature, rising sea levels, increases in incident UV radiation, irregular changes in average annual precipitation, and increases in the variability and intensity of extreme weather events. Greater climate variability will surely complicate the task of identifying impact pathways and areas of vulnerability requiring research to devise and promote coping strategies and improve the adaptability of fishers and aquaculturists especially in the developing countries. Many coastal and island communities where poverty is widespread and livelihood alternatives are limited depend heavily on fish resources for their well-being. Fish also provides an important source of cash income for many poor households especially in Africa. This paper examines the ways in which climate change and extreme events may directly affect fisheries and aquacultural production in Africa. Specifically the paper looks at the effects on African river fisheries, coastal fisheries, coral reefs and mariculture. It presents the implications for this important sector on the people, resources and the environment. The paper recommends (a) the strengthening of capacity including that of African scientists, governments and civil society; (b) supporting adaptation by rural /urban people particularly the most vulnerable and (c) adding value to existing adaptation initiatives to enable African scientists to apply expertise and carry out research in support of adaptation projects in land-water interface ecosystem. Introduction Climate change is environmental change, but given that human societies are affected directly and indirectly by the climate system – and given that human activities are driving climate change – it is fundamentally a human problem. Climate change cuts across boundaries. The impacts of climate change are expected to seriously (and disproportionately) affect the livelihoods, health, and educational opportunities of people living in poverty, as well as their chances of survival, both locally in specific areas and globally in general. As a global environmental challenge, the drivers of which are inextricably linked with highconsumption lifestyles, climate change lies firmly outside the sphere of influence of poor communities and poor countries, which have little say in how the challenge will be addressed. Those with special burdens and/or vulnerabilities such as women, ethnic minorities, and people living with HIV/AIDS are feeling yet another pressure in global warming – one that is fundamentally unjust. The impacts of climate change will affect everyone; some have calculated that the costs associated with overcoming climate impacts could even exceed global economic output within a few generations.