The invasive water hyacinth (Eichhornia crassipes) poses a significant threat to aquatic ecosystems but also offers a potential alternative to expensive fishmeal in aquaculture feeds. The study evaluated the growth performance and survival of juvenile Clarias gariepinus (weight: 4.95±0.154 g and length: 9.07±0.378 cm) fed diets with varying levels of water hyacinth leaf meal (WHLM) as a fishmeal (FM) replacement. The diets were TD1 (100% FM), TD2 (25% WHLM), TD3 (50% WHLM), TD4 (75% WHLM), and TD5 (100% WHLM). A 49-day feeding trial, conducted in a controlled condition, monitored fish growth, survival and water quality parameters. The feeding experiment was conducted in fifteen plastic tanks of 50-liter capacity each stocked with 10 juvenile C. gariepinus. The fish were fed twice daily at 3% of body weight. The control diet (TD1 diet) exhibited the best growth, followed by TD2, TD3, TD4 and TD5 diets. Analysis of variance revealed significant differences (p < 0.05) in weight gain, specific growth rate, feed conversion ratio and average daily growth between the control and WHLM-containing diets. Water quality parameters remained within acceptable limits for juvenile C. gariepinus growth, indicating that WHLM can be a suitable partial replacement for fishmeal. The study therefore suggests 25% water hyacinth leaf meal as a promising diet for sustainable production of juvenile gariepinus.
Aquaculture system design plays a critical role in influencing the growth performance and survival of cultured fish species, particularly in intensively farmed catfish. This study evaluated variations in growth performances and survival rates among two widely cultured catfish species in Nigeria (Clarias gariepinus and Heterobranchus bidorsalis) and their hybrid (Heteroclarias) under flow-through and recirculatory aquaculture systems. Three Hundred (300) hatchery bred fry (14 day old) each of C. gariepinus, H. bidorsalis and Heteroclarias were randomly selected and stocked separately in triplicate (100 fish/replicate) experimental plastic tanks (1.2 x 0.6 x 0.5m3 ) connected to recirculatory and flow-through systems. The fish were fed ad libitum four times daily with commercial feed (40% CP) for 60 days. Growth performances and survival rates of the fish were estimated according to standard formulae. Data collected at the end of the feeding trials were subjected to t-test and one way analysis of variance. Results showed that final mean weight and weight gain (WG) differed significantly (p < 0.05) among treatments. Fish reared in recirculatory system generally recorded higher final weights and weight gains when compared with those reared in flow-through system. C. gariepinus in the recirculatory system achieved the highest final weight (4.34 ± 0.13 g) and weight gain (4.25 ± 0.12 g), while the lowest values were observed in C. gariepinus and H. bidorsalis reared under flow-through conditions. Daily growth rate values ranged from 0.06 to 0.07 g day⁻¹, while specific growth rates ranged from 6.21 to 6.68%day⁻¹. The highest survival rate was observed in Heteroclarias reared in the recirculatory system (88.78 ± 1.09%) and lowest in H. bidorsalis under flow-through conditions (86.22 ± 0.62%). In conclusion, recirculatory systems enhanced catfish growth and survival, with the hybrid strain (Heteroclarias) showing superior growth performances when compared with the parent stock (C. gariepinus and H. bidorsalis) in both culture systems.
Improving the growth, resistance and survival of Nile tilapia (O. niloticus) in aquaculture has important role in optimizing the production and profits. Carrot (Daucus carota) is a potential local nutraceutical that has antioxidative and immunostimulant properties. This study was performed to investigate the influence of carrot powder added in fish feed on the growth, survival rate and food conversion ratio of O. niloticus. A 90-day experiment was conducted on Nile tilapia of an average body weight and standard length of 0.5±0.02g and 3.5 0±0.5 cm respectively. The experiment was conducted in 70 litre plastic bowls with a water volume of 40 litre and 20 fish per bowl were given five treatments in three replications. Different carrot powder proportions of 0%, 6.15%, 9.23%, 12.3% and 15.38% were administered. Growth performances and water quality variables were measured using standard procedure. The highest final weight of 5.04±0.05g was obtained at 15.38% inclusion of carrot powder. Similarly, the highest mean weight gain (MWG) of 4.56±0.12g was recorded at T5 (15.38% inclusion of carrot powder), while the least MWG (3.57±0.05g) was obtained at T1 (0% inclusion of carrot powder). Significantly higher (p<0.05) specific growth rate (2.33±0.03%/day), protein efficiency ratio (0.95±0.01) and the best food conversion ratio (3.00±0.03) were recorded in fish treated with 15.38% inclusion of carrot powder. Survival rate of 95.6±0.00% was recorded at 0% and 6.15% inclusion levels of carrot powder, while there was 100% survival at 9.23%, 12.3% and 15.38% carrot powder inclusion levels. The levels of water temperature, pH, dissolved oxygen and ammonia were maintained within the ranges of 25.32±0.58°C to 25.87±1.54°C, 6.34±0.71 to 6.54±0.76, 5.21±0.48mg/l to 5.88±0.65mg/l and 0.04mg/l respectively. The results showed that carrot powder had significant effect on mean weight gain, specific growth rate, food conversion ratio and protein efficiency ratio of O. niloticus.
Brood stock quality is essential to a successful and viable fish seed production. Determinant of this quality includes age, physical and genetic makeup. Influence of brood stock body weight on reproduction and performance of Heterobranchus longifilis × H. bidorsalis was studied. Brood stock pairs of varying weights (1 kg, 1.5 kg, and 2 kg) were artificially spawned, and resulting eggs incubated under controlled conditions. The experimental design involved six treatments, (Treatment 1=1kg, Treatment 2=1.5kg, Treatment 3 =2kg, all males = Heterobranchus longifilis while Treatment 4 =1kg, Treatment 5=1.5kg, Treatment 6 =2kg, all males = Heterobranchus bidorsalis), replicated thrice. Parameters assessed included egg count per gram, hatchability, weight gain, specific growth rate, feed conversion ratio (FCR), and survival rate over an 8-week period. Water quality parameters were maintained within optimal ranges. Treatments with moderate-weight females (T1, T2, and T4) produced higher egg counts per gram, while heavier females (T3, T5, and T6) yielded lower counts but with significantly higher hatchability rates. Eggs in T6 had the highest hatchability (56.33%). Growth performance indicators: final weight (5.37±0.47 to 5.07±0.52g), FCR (2.81±0.26 to 3.23±0.50), SGR (0.6697±0.0710 to 0.6608±0.1031%/day) and survival rate (58.33 ± 2.52 to 52.00±10.44%) did not differ significantly (p > 0.05) among treatments, indicating uniform post-hatching performances. The findings highlight a trade-off between fecundity and egg viability, larger brood stock may enhance hatchability despite reduced egg output. For optimal hatchery productivity, brood stock selection should consider not just egg quantity but also fertilization success and larval viability.
Coastal lagoons, such as the Lagos Lagoon, are ecologically significant ecosystems that are becoming increasingly vulnerable to human-induced stresses, such as urbanization, pollution, and industrial activity. This study evaluated macroinvertebrate compositions and ecological quality status of the Lagos Lagoon using the AZTI Marine Biotic Index (AMBI) to assess responses to these perturbations. Ten (10) stations were sampled across the Lagoon during both dry and wet seasons. Water and sediment samples were obtained using bottom water samplers and a Van Veen grab respectively, and analyzed for physicochemical parameters and macroinvertebrate compositions using standard techniques. Analysis of variance showed significant seasonal changes (p < 0.05) in water temperature, dissolved oxygen, salinity, conductivity, and total dissolved solids. Ten (10) taxa (abundance: 237 individuals) were recorded during the wet season and 9 taxa (abundance: 226 individuals) in the dry season. These taxa belonged to three phyla: Mollusca, Arthropoda, and Annelida. The Shannon-Wiener diversity index ranged from 0.77 to 1.91 (wet season) and 0 to 1.21 (dry season), suggesting low diversity. Simpson's dominance index ranged from 0.60 to 0.86 (wet season) and 0.08 to 0.74 (dry season). AMBI revealed a slight level of ecological disturbance across all Stations, except Stations 6 and 7, with moderate disturbance in both seasons. The findings improved the understanding of the impact of numerous stresses on benthic macroinvertebrate ecosystems and illustrated the usefulness of biotic indices in ecological assessments.
Heavy metals are considered contaminants, and when present in aquatic environment, may lead to pollution of aquatic organisms through their toxic effects and bioaccumulation. Health risk associated with the consumption of contaminated sea food had become a global concern. The study was conducted to assess concentrations of heavy metals: lead (Pb), cadmium (Cd), chromium (Cr), copper (Cu) and Iron (Fe) in Tympanotonum fuscatus samples, as well as estimating the potential human health risk associated with the consumption of this fish obtained from Mbo Channel of the Cross River Estuary. The USEPA Guidelines for health risk based concentrations were employed for estimation of target hazard quotient (THQ), hazard index (HI) and target cancer risk (TCR). Water quality variables were also measured following standard protocols. Results showed significant differences (p < 0.05) in metal contamination indices in both water and fish samples. The principal component analysis (PCA) results showed that the total variance was 92.48%, and PC 1 was represented by Cd and Cr while PC 2 was dominated by Pb. The results for HI were: Cr (2.541 mg/kg), Cd (7.131 mg/kg), Pb (1.657 mg/kg), Cu (0.344 mg/kg) and Fe (0.193 mg/kg). The levels of Pb, Cd and Cr in fish fresh all exceeded the WHO permissible limit of 1.0 mg/kg. Although these metals have not been associated to toxicity, a potential adverse health risk may be associated with the consumption of T. fuscatus from the estuary. TCR values of the metals analyzed showed that Cr and Cd had high potential cancer risk while Pb had moderate risk factor in humans over 70 years of consumption. The health risk associated with accumulated metals in T. fuscatus underscores the need for periodic biomonitoring of the Cross River Estuary system.
High cost of fish feed and poor nutrition are the major setbacks in catfish culture. Fish oil enhances feed acceptance, organoleptic qualities and growth of fish. Thus, the combination of different lipids can increase growth and oxidative stability of fish.This study evaluated effects of palm oil meal effluent sludge and sesame seed meal on growth and gut microbiome of the African catfish, Clarias gariepinus. Five feeds were produced to vary in the inclusion levels of palm oil effluent sludge (POME) and sesame seed oil meal (SSM) in the following ratio: F1 (POME:SSM 400:0g), F2 (POME:SSM 300:100g), F3 (POME:SSM 200:200g), F4 (POME:SSM 100:300g) and F5 (POME:SSM 0:400g). Other ingredients were added at same levels while a sixth diet (commercial catfish feed) served as the control. African catfish of average initial weight of 10.7-14.2g were stocked at 15 fish per treatment with each treatment replicated three times and fed both the experimental and control diets for 90days. The fish were fed ad libitum. Determination of bacterial loads in fish parts were done using standard microbiological procedures while standard formulae were used to calculate various growth parameters. Results revealed that inclusion of POME and SSM in the diets of juvenile catfish had profound effects on the growth and food conversion ratio. Fish treated with F1 gave the best performance in terms of specific growth rate (SGR; 3.68±0.07%day-1 ) and food conversion ratio (FCR; 1.54±0.01). The gut morphology of the catfish showed that catfish fed F2 (300gPOME:100gSSM), had the highest gut weight (1.25±0.01g) and longest intestinal length (19.93±0.05mm) than catfish fed all other feeds (p<0.05).The catfish fed with F1 had dominant microbial communities of Gram -ve rod including Enterobacter sp. and Escherichia coli. Those fed F2 (POME:SSM 300g100g), had Gram +ve, non-spore forming anaerobic rod, Lactobacillus sp as dominant species while those feed F5 (POME:SSM0g:400g) had Gram-ve rod, Klebsiella sp as part of the dominant species. The outcome of the present study support the inclusion of more of palm oil mill wastes in fish feed formulation.
Nutraceuticals are natural substances that are food or part of food to provide medicinal and health benefits, and also have the potency to prevent and treat diseases. The present study evaluated phytochemical compositions of clove (Syzygium aromaticum) flower bud extract with a view to evaluating its potential as a natural dietary additive in Clarias gariepinus diet. Clove powder was incorporated at four levels (0, 5, 10 and 15%) of the experimental diets and fed to the fish in triplicate for 84 days. All analytical protocols followed standard procedure. Phytochemical screening of clove revealed the presence of primary metabolites: carbohydrates, proteins, and lipids (in trace to moderate amounts), as well as secondary metabolites: alkaloids, flavonoids, tannins, sterols, saponin, cardiac glycosides, and phenolic compounds. Proximate analysis of clove extract showed high levels of carbohydrates (46.65±0.006%) and lipids (21.67±0.003%), with a caloric value of 413.83 kcal/100g, while protein content was relatively low (8.05±0.006%). Mineral analysis revealed potassium (10.10±1.03 mg/100g) as the most abundant element, followed by calcium, phosphorus, iron, magnesium, and zinc. Nutrient analysis showed appreciable amounts of vitamins A, B1, B2, and C., while anti-nutritional factors such as oxalate and phytate were present in low concentrations. The catfish treated with 15% clove extract in diets had the best specific growth rate (0.46±0.67%/day), average daily growth (1.56±0.01g/day), food conversion ratio (0.131±0.00) and protein efficiency ratio (37.6±3.40). Fish condition factor and survival rates followed similar trend. The results suggested that S. aromaticum extract contained beneficial phytochemicals and essential nutrients which may be suitable for use as a natural feed supplement. These bioactive compounds enhanced fish growth and feed utilization which increased with inclusion levels in diets. Thus, the use of clove bud extract in catfish feed in hereby encouraged.
Fish and fishery products significantly contribute to global food security and nutritional needs. The present study was carried out to determine fish biodiversity of Okomu National Park, Niger Delta Region of Nigeria. The icthyofauna composition of the wetland was studied monthly from August to October, 2018 to compare the presence, distribution and abundance of fish species in the lotic (Okomu River and Arakhuan Stream) and lentic water bodies within the ecosystem. Fish samples were collected with fishing nets of various mesh sizes using the standard capture and return technique. The results of the study revealed 71 fish specimens belonging to six (6) Orders, eight (8) Families and twelve (12) species. The fish species recorded included: Xenomystus nigri, Petrocephalus bovei, Gnathonemus petersii, Pelmatochromis pulcher, Oreochromis aureus, Tilapia zilli, Tilapia dageti, Micralestes elongates, Citharinops distichodoides, Parachanna africana, Erpetoichthys calabaricus and Malapterurus electricus. No fish sample was observed in the temporary ponds under investigation. This may be due to predation, seasonality, and water quality. However, the lotic systems supported fish population, where 10 fish specimens were obtained from Arakhuan Stream while Okomu River had 61 specimens. The family, Cichlidae dominated in the study area and constituted Tilapia zilli (22.5%), Tilapia dageti (18.3%) and Oreochromis niloticus (16.9%) of the total catch. The study demonstrated that the lotic segment of the Okomu Wetland supported fish diversity and provided valuable baseline information for future research.
Fishing gear design is the process of preparing technical specifications that will aid in providing sections of the gear drawing. This painstaking examination is to ensure proper gear handling technique and operation, including satisfying economic and social considerations. The design strategies of cast net in Escravos Estuary within Okerenkoko, Delta State, Nigeria was studied in three stations: Station 1 {University Jetty (UJ)}, Station 2 {Zion Jetty (ZJ)} and Station 3 {Vigilante Jetty (VJ)} between April and June, 2025. Two types of castnets were identified in the study area. The cast nets had length circumference ranging from 4.0 to 8.0 m, the retrieval lines measuring between 3.0 to 6.0 m while the thickness ranged from 3.0 to 6.0 mm. The netting material used in the study area consisted of R 100 – 310 tex polyamide twines of z – twist disposition with stretched mesh sizes ranging from 25 to 50 mm with hanging ratio of 0.5. It was observed that the netting section of the cast nets were horizontally segmented into panels.The segmented cast nets consisted of two to three segments and each segment was found to be made of netting with different mesh sizes (50 mm, 30 mm and 25 mm) and R – tex twine sizes. This range of mesh sizes observed in most of the cast nets in the study area were in line with the Inland Fisheries Decree 108 of 1992, especially cast nets used in fishing species such as Ethmalosa fimbriata and Sardine llaaurita in the study area. The results revealed that, polyamide nettings were the most commonly used materials in constructing the cast nets, and this polyamide netting materials are highly recommended for use in constructing cast nets due to their high quality and tensile strength. This is a pilot study in the area for cast nets fisheries, but more studies are still needed to provide tangible recommendations.
The destruction and unsustainable use of forest resources necessitated the establishments of protected areas (National Parks) in many countries including Nigeria. The study assessed the terrestrial ecosystem services of Okomu National Park between August, 2017 and January, 2019, with a view to assess its fauna and flora diversity. Three compartments (each approximately 1.5 km²) were selected for plant assessment, while eight compartments were used for animal assessment. The transect method was employed to evaluate species abundance by counting individuals within each transect. The survey recorded 16 terrestrial animal species, with Cercopithecus erythrogaster (White-throated monkey) being the most abundant (31.21%), while Naja sp., Xercus erythropus, Loxodonta africana cyclosis, Phataginus tricuspid and Synercus caffer nanus occurred the least (0.58 % each). For flora, 23 species were observed, with Ceiba pontandra (13.07 %), Ceitis bondii (11.59 %), Anthonatha macrophylla (10.14 %) and Rothmannia wipidia (11.59 %) as the most abundant plant species. The study revealed the wetland's diverse fauna and flora compositions, highlighting its importance for biodiversity conservation and ecosystem services. The park's potential for ecotourism, research, and recreation is substantial. It is also very important to involve surrounding communities in park management and resource use to help mitigate conflicts, illegal logging, and poaching. To ensure sustainable management, it is recommended that, more researches be carried out including ecosystem valuation.
Anaesthetics are commonly used in aquaculture to minimize the incidence of stress in fish. The study assessed effects of metomidate as anaesthetics on induction and recovery time in male and female brood fish of Clarias gariepinus as well as on some water quality variables {pH, dissolved oxygen (DO), temperature, ammonia and nitrite}, following standard procedures. Thirty-six (36) brood C. gariepinus consisting of eighteen (18) gravid female (mean length 60.23 cm±0.36 and 2.64 kg ±19.36) and eighteen (18) matured male (mean length 58.12 cm ±0.47 and 1.98 kg ±45.11 were exposed to 0.00 (control), 2.00, 4.00, 6.00, 8.00 and 10.00 mg/L in triplicates. Results showed that induction time(s) in both sizes of exposed fish decreased (660.00±18.98 at 2.00 mg/L to 228.00±20.72 at 10.00 mg/L) as metomidate concentration increased, while the recovery time(s) increased as metomidate concentration increased (490.00±23.07 at 2.00 mg/L to 862.00±28.15 at 10.00 mg/L). The survival rates in male and female C. gariepinus exposed to metomidate were 100.00 % (0.00 mg/L and 6.00 mg/L of metomidate). The results indicated that metomidate did not cause any significant change (p>0.05) in water quality variables in all exposure concentrations. A reduction in DO, (5.22±0.78 mg/L in the control to 4.96±1.16 at 10 mg/L anaesthetics concentration) and slight increase and decrease in ammonia (0.35±0.01 mg/L; 0.28±0.11 mg/L) and nitrite (0.02±0.01 mg/L; 0.03±0.01 mg/L) were observed at 6.00 to 10.00 mg/L of metomidate. The study therefore established 4.00 mg/L as ideal concentration for C. gariepinus exposure to metomidate for optimum production in aquaculture venture.
Fish farming is a vital economic activity contributing to food security and employment in many regions. However, feed costs constitute a significant portion of production expenses, necessitating an evaluation of the economic implications of using local and foreign feeds. This study evaluated the economic implications of using local, foreign, and combined feeds in fish farming while analyzing the socioeconomic characteristics of fish farmers and the factors influencing feed choice. Primary data were gathered through structured questionnaires from local fish farmers in the study area, some of the farmers who could not write were interviewed and data analyzed using descriptive statistics, regression analysis, and a ᵶ -test to determine cost and revenue differences between feed types. Results showed that 66.7% of respondents were male, with an average age of 45 years. The majority (43.3%) had secondary education, and the average annual income from fish farming was ₦450,000. Economic analysis revealed that farmers using both feeds had the highest production cost (₦404,175) but also the highest gross revenue (₦4,327,500). However, those using foreign feed achieved the highest benefit-cost ratio (BCR) of 18.0, compared to local feed (17.2) and combined feeds (13.0). Regression analysis indicated that gender, marital status, educational level, household size, income, access to extension services, and number of fingerlings stocked significantly influenced feed choice (R² = 0.793). The ᵶ -test confirmed a significant difference in costs (ᵶ = 50.851, p <0.05) and revenues (ᵶ = 20.571, p<0.05) between feed types, demonstrating that feed selection greatly impacts profitability. These findings highlight the economic advantage of foreign feeds despite their higher costs. The study showed the importance of education and extension services in optimizing feed selection, aiding policymakers in enhancing fish farming sustainability.
The Niger Delta region has provided livelihoods for many individuals and communities through artisanal fisheries for generations till date. Evidence-based reports are invaluable to aid develop sustainable management strategies for the region. The Multidimensional Poverty Indices (MPI) was used to examine the extent of deprivations among the fishing communities in Southern Ijaw Local Government Area. Data were collected through structured questionnaires programmed in an android survey-based application (Kobo Toolbox). Purposive sampling technique was used to select five (5) fishing camps: Ikoromogbene, Ipirigbene, Okongbene, Ofinigbene and Ogilagbene, and snowballing approach was used to select eight (8) other communities: Oporoma, Ekowe, Angiama, Ayama, Nangiama, Onyoma, Opuama and Amasomma based on their fishing activities and history. A total number of 132 fisher folks were randomly interviewed from the 13 selected communities. Descriptive statistics was employed in the data analysis. The results showed gender parity among the fisher folks. The majority of respondents 56(42.42%) had secondary education as their highest academic attainment. Over 105(79.55%) were married, and have household sizes ranging from 6-10. Respondents were found to earn below the global poverty threshold of $2.50/person/day. The respondents' living conditions were characterized by limited financial resources, inadequate housing (mud/thatched), reliance on primitive energy sources (kerosene stove, firewood) and unimproved water and sanitation facilities resulting in high incidence of typhoid diseases outbreak among others. Income was basically utilized on carbohydrates rich diets, school fees and healthcare services. The fisher folks trekked an average of 4km to access these essential services. Lack of access road to the remote locations, water transportation system, poverty, and inadequate provisions of corporate social responsibility were perceived to be the major factors responsible for the multidimensional deprivations in the study area. To enhance livelihood standards, the study recommends collaborative approaches and policies between State and Non- State actors including local communities to effectively implement poverty reduction initiatives.
In fish, like other organisms, the imbalance between the production of reactive oxygen species (ROS) and antioxidant defence system can cause destructive effects on lipids, proteins, and Deoxyribonucleic acid (DNA). A bioassay was conducted on toxic stress indices of Oreochromis niloticus using aqueous solutions of NPK 15-15-15 fertilizer corresponding to the application rate of 120kg/ha/2weeks on a 1ha pond of 0.8m depth. This was serially diluted to yield 0.0mg/l and 15mg/l in control and treated groups respectively. Each treatment was replicated three times. Twenty (20) Day After Hatching (DAH) post yolk sac larvae of Nile tilapia with initial mean length and weight (2.25 cm and 0.44g) respectively were used as test organism. A total number of six (6) rearing troughs with a dimension of 1m×1m×0.5m were used for the study. Post-yolk sac larvae of O. niloticus were raised in the fertilizer solutions for a period of six months (March to August, 2024) at a stocking density of 100 larvae/rearing trough. The levels of ROS, superoxide dismutase (SOD), and total protein (TP) of O. niloticus were determined at the initial stage, 96hrs (March), June and August following standard procedure. Temperature, dissolved oxygen, pH, total hardness, nitrate and phosphate were monitored accordingly. Results showed significant differences (p<0.05) in the levels of TP, SOD and ROS at initial stage, 96hrs (March), June and August between thecontrol fish and those challenged with NPK 15-15-15 fertilizer. Also, the inclusion of fertilizer to the culture media, significantly affected (p<0.05) all the physico-chemical variables of water except temperature. Fish have been the models for aquatic environmental toxicity tests. These findings therefore signal a potentially more pervasive ecosystem damage from fertilizer use, affecting productivity of inland water bodies.
Lack of sufficient and sincere information on current socio-economic conditions of fishing communities is one of the serious impediments in proper planning and development of various fisheries management programs. The socio-economic analyses of small-scale fisheries in some fishing communities in Oguta Local Government Area, Imo State were examined. Multi-stage random sampling technique was employed in the primary data collection with the use of a structured questionnaire. Initially, six (6) inland lakes/fishing camps: Oguta, Okutu, Ibina, Inyima, Nnemiri and Amaja were selected out of the fishing settlements. The second stage involved the random selection of 70 respondents from the six fishing settlements. The collected data were analysed using descriptive statistics. The results showed that fishing in the study area was male dominated (100%), and also the major occupation of the majority (74.29) of the respondents. The highest academic qualification of the respondents was Senior Secondary Certificate accounting for 57.14% of the respondents. Majority of the respondents (74.29%) were Christians, (75.71%) were married with household size ranging from 6 – 10, accounting for 50% of the respondents. The average monthly income by majority (48.57%) was between N20,000 – N30,000. The reports also revealed that, 95.71 and 84.29% of the respondents owned their gears and crafts respectively. Feeding (81.41%) and school fees (68.57%), characterized the major household expenditure. About 78.57% had no savings, thereby depended on friends and relatives for source of finance. Firewood (82.83%) and locally fabricated battery lantern (48.57%) constituted the major cooking fuel and source of electricity respectively. Iliteracy, poverty and poor governance were perceived to be the major factors militating the development of artisanal fisheries in the study area.
The regular monitoring of the physico-chemical properties of river and its quality for aquatic flora and fauna is of immense significance and it suitability for human use cannot be overemphasized. This study investigated the physico-chemical properties of the River Niger at Cable Point in Asaba, Delta State, Nigeria. Three sampling Stations: 1 (Marine), 2 (Nnebisi) and 3 (Onishe) where established. Water samples were collected monthly between the hours of 7.00 to 8.00 am for 12months (May, 2023 to April, 2024) using standard laboratory procedure. The collected samples were analyzed for some parameters such as: temperature, pH, dissolved oxygen (DO), electrical conductivity (EC), biological oxygen demand (BOD), calcium and magnesium following standard methods. Results showed that temperature value ranged from 28.55 °C in Station 2 to 29.50 °C in Station 3, pH values were 6.70 and 8.57 in Stations 1 and 2 respectively, iron (0.07 to 0.43 mg/l) and nitrates (1.14 to 1.83 mg/l) were not significantly (p > 0.05) different across stations. Other parameters: EC (61.11 and 129.92 µS/cm in Stations 1 and 2), DO (5.43 and 11.82 mg/l in Stations 1 and 3), BOD (2.16 and 6.87 mg/l in Stations 2 and 3), calcium (67.46 and 150.78 mg/l in Stations 2 and 3) and magnesium (67.78 and 72.08 mg/l in Stations 2 and 3) showed spatial variations (p < 0.05) during the rainy season. While pH, DO, BOD and total dissolved solids were within WHO acceptable levels, calcium, total suspended solids, iron, and phosphate values at Stations 2 and 3 were above WHO permissible limits (TSS: 25mg/l, calcium: 75-100mg/l, iron: 0.05-0.3mg/l and phosphate: 0.1mg/l). The slight increase in these variables may be due to the presence of anthropogenic substances in the river under study. Therefore, the water of River Niger at Cable Point, Asaba, Delta State, Nigeria may not be suitable for drinking and may pose a risk to both aquatic life and humans if left unmonitored.
The use of ichthyotoxic plants to stupefy fishes is a common fishery practice in tropical regions despite the superiority of modern netting materials and prohibition by law. Though these plants derivatives are believed to be nontoxic compared to their synthetic counterparts, they may contain a number of harmful ingredients or their secondary metabolites may have deleterious side effects. This study investigated the physico-chemical parameters of water media exposed to varying concentrations of Aidan, Tetrapleura tetraptera aqueous extract and their implications for the hatching success of Clarias gariepinus. Mature leaves of T. tetraptera were harvested, verified, crushed, and soaked in 6 liters of borehole water to obtain the stock solution. Serial dilutions were prepared from this solution into six treatments with the following concentrations: 75, 50, 25, 12.5, 6.25, and 3.125 ml/l designated as T1 to T6 respectively. The seventh treatment served as the control (without extract). Fertilized egg masses of C. gariepinus were exposed to the different concentrations of the aqueous extract in 15-liter plastic containers for 96 hours, during which period observations were made. Hatching success and water quality variables were determined according to standard procedures. The study revealed significant alterations in physico-chemical parameters, including dissolved oxygen (3.27 mg/l), pH (4.07), conductivity (63.11uS/cm), total dissolved solids (32.1 mg/l), and biochemical oxygen demand (0.67 mg/l) across treatment groups. A dose-dependent effect of T. tetraptera on hatching success was observed, with higher concentrations (T1 and T2) leading to decreased hatching rates. The T6 group exhibited the highest hatching success of 90%, while other treatment groups showed significantly (p<0.05) lower rates, with the highest concentration (75ml/l) resulting in only 10% hatching success. The findings of the present study underscore the potential risks associated with the use of T. tetraptera in capture fisheries. It also highlighted the need for strategic management of plant extracts to ensure the health and viability of fish populations and aquatic ecosystems.
Microalgae are a diverse group of unicellular photosynthetic organisms which contain high levels of proteins, lipids, carbohydrates, pigments, minerals and vitamins in different quantities, thus, could be used as feed supplement in catfish production. The study investigated growth response, proximate composition and bioactive compounds present in Chlorella vulgaris cultured on different quantities of pure poultry manure. Pure 200cl sample of C. vulgaris isolates was procured from the Limnology Unit of National Institute for Freshwater Fisheries Research (NIFFR), Niger State. Five different weights (10kg, 20kg, 30kg, 40kg and 50kg) of pure and dried poultry droppings were each soaked in 10 liters of water for two hours and inoculated with 13.33cl C. vulgaris isolates following standard procedures. Each treatment was then poured into70 litres culture plastic tanks containing 40 liters of clean water and was used for the culture of C. vulgaris. The culture systems were exposed to 10hrs daily sunlight illumination and culture duration was 16 days. Each treatment was replicated three times. Results on analysis for bioactive compounds showed that carotenoids, phenols and chlorophylls a and b were detected in the biomass of C. vulgaris signifying a good fish food source. High protein (32.41%), ash (30.33%) and metabolizable energy (262.12Kcal/g) were recorded. The treatment group containing 30kg poultry manure had the highest cell density (19.67ml/l), biomass productivity (1.82ml/l), growth rate (3.52g) and substrate consumption percentage (49.99%). This concentration provided excellent and sustainable conditions that enabled C. vulgaris multiplication. While the 10 and 20kg treatment groups recorded lower growth resources, higher concentrations of 40 and 50kg showed light penetration problems. The 30kg pure poultry manure quantity is therefore recommended for the culturing of green algae, C. vulgaris which could be used as feed supplement in the culture of Clarias gariepinus.
Fish, renowned for being a rich source of vital nutrients such as high-quality protein, polyunsaturated fatty acids, and essential minerals, can also act as a reservoir for zoonotic bacterial pathogens. These pathogens often indicate the level of environmental contamination in aquatic ecosystems. The study evaluated zoonotic bacterial pathogens in catfish and pond water samples from selected fish farms in Ebonyi State, Nigeria. A total of 72 samples, including catfish (48 samples) and pond water (24 samples), were collected from three locations: Abakaliki, Afikpo, and Ngbo. Standard microbiological and biochemical methods were employed to isolate, enumerate, and identify bacterial species. Morphological and biochemical analyses revealed the presence of Aeromonas sp., Vibrio sp., and Streptococcus sp. in both catfish and pond water samples. The biochemical analysis showed that Streptococcus sp. were positive to oxidase, lactase, glucose, sucrose, methyle red and catalase tests but showed negative result with Voges-Proskauer (VP) and citrate tests. However, Aeromonas species were positive to lactase, glucose, sucrose, methyl red, catalase, oxidase, indole and methyl red tests while Vibro species revealed to be variable to methyl red and VP-negative but positive to oxidase, lactase, glucose, sucrose, catalase and indole-negative, which were the same for both catfish and pond water samples. According to the distribution pattern of these microbes in the test samples, Aeromonas sp showed the highest prevalence (13.9%) in both test samples, while (18.75%) and (25%) were recorded in catfish and pond water respectively; their distribution across the three locations within the test samples were not statistically significant (p > 0.05), followed by Vibrio spp. (12.5%) in both samples while (18.75%) and (25%) were recorded in catfish and pond water respectively which their distribution were significant (p<0.05) and Streptococcus sp showed 8.3% in both samples while (12.5%) and (12.5%) were recorded in catfish and pond water respectively and the distribution pattern in the samples were not significant. The findings indicated compromised water quality in fish farms which is evident in the increased bacteria load, were likely influenced by environmental conditions and management practices.
