Nigerian Journal of Fisheries and Aquaculture

Drivers of Modern Technology Utilization in the Fisheries Sector of Lagos State, Nigeria

Aminu, F. O. — 2026-05-29

The utilization of modern technology in the fisheries sector is critical to improving productivity, sustainability, and livelihoods in the face of increasing demand and environmental challenges. This study investigated the drivers influencing the utilization of modern technologies in the fisheries sector of Lagos State, Nigeria. Specifically, it identified the modern fishing technologies currently being utilized in the sector and determined the major drivers influencing the utilization of these technologies in the study area. Primary data were collected through administration of structured questionnaires to 120 randomly selected fish farmers across four major fish-producing local government areas in the state. Descriptive and inferential (multiple regression) statistics were used for the data analysis. The study found that majority (60%) of fish farmers were male, with a mean age of 37.91 years. Factors such as sex, age, education level of the respondents, fishing experience, income, access to loan and the frequency of extension visits significantly drove the utilization of modern technologies (improved pond liming and fertilization, culture methods and fertilities, feed preparation and feeding methods, gear technology, value addition, preservation, processing and marketing technologies). The study concluded that the utilization of modern technologies in Lagos State’s fisheries sector is driven by diverse socioeconomic and institutional factors, highlighting the need for deeper understanding of these influences to encourage wider and more effective technology utilization in the fisheries sector. Enhancing these drivers will not only improve fish yield and income but also contribute to food security and sustainable growth of the fisheries sector in Lagos State.

Effect of Pollution on the Length-Weight Relationship, Condition Factor and Heavy Metal Concentrations in Ethmalosa Fimbriata and Chrysichthys macropogon from Coastal Waters of Ilaje, Ondo, Nigeria

Ojo, O.B. — 2026-05-29

This study investigated the impact of pollution on the length–weight relationship, condition factor, and heavy metals on Ethmalosa fimbriata and Chrysichthys macropogon in the coastal waters of Ilaje Local Government Area, Ondo State, Nigeria. The study aimed to evaluate the health status of the fish and provide insight into potential environmental risks. Fish samples were collected monthly over four months (April–July) from four fish landing sites: Ayetoro, Bijimi, Idiogba, and Asumogha. The fish were caught using gillnets with mesh sizes ranging from 0.6 cm to 4.0 cm. Standard length and weight measurements were taken, and length–weight relationship parameters were determined through regression analysis, while condition factors were calculated to assess fish health. Results revealed that the mean total lengths of E. fimbriata ranged from 16.72±4.40cm (Bijimi) to 20.20±4.94cm (Idiogba), and weights ranged from 62.18±34.30g (Bijimi) to 92.78±52.31g (Idiogba). For C. macropogon, mean lengths ranged from 16.82±4.97 cm (Asumogha) to 19.19±6.53 cm (Idiogba), and weights ranged from 65.28±41.28g (Asumogha) to 94.94±57.49g (Bijimi). Condition factors for both species fell within 0.60–1.70, indicating fair to good health despite detectable levels of copper, cadmium, and manganese (Mn) in fish tissues. E. fimbriata in Ilaje shows hyperallometric growth, while C. macropogon displays an allometric growth pattern. The length–weight relationship exponent (b) values deviated from 3 in most cases, indicating allometric growth patterns. The accumulation of heavy metals suggests ongoing environmental contamination, which may have implications for fish productivity, ecosystem health, and food safety in the study area.

Effects of Guava (Psidium guajava) Aqueous Leaf Extract on Total Heterotrophic and Coliform Counts in Intestinal Tract of Oreochromis niloticus (Lennaues, 1758)

Ajani, E. K. — 2026-05-29

Antibiotic use in fish farming is increasingly restricted due to associated risks. This study examines the effects of guava (Psidium guajava) leaf extract on Oreochromis niloticus gut bacteria and body composition. This is to establish if the extract selectively reduces enteric pathogens without disrupting beneficial microbiota and the body composition, a critical growth indicator. Psidium guajava leaves were collected from the botanical garden, University of Ibadan, washed, air-dried for 3 weeks, and milled into powder form. Aqueous extracts from the powder were screened quantitatively and qualitatively using standard procedures. Five isonitrogenous diets (35% Crude protein) were formulated containing 0, 0.25, 0.50, 0.75, and 1.00% P. guajava extract. Diets were fed to triplicate groups of 300 O. niloticus (mean weight: 1.32 ± 0.04g) twice daily to satiation for 84 days. Initial and final proximate compositions of experimental fish were determined using standard methods. Total heterotrophic count and total coliform count were carried out on the aseptically removed guts. Psidium guajava extracts contained 14.6% alkaloids, 22.4% flavonoids, 36.6%, saponins while tannin was 18.3 %. Total heterotrophic count and Total coliform count (1.92 x 10⁴ cfu/g and 1.40 x 10⁴ cfu/g, respectively) were significantly higher (P<0.05) in the gut of fish fed control group compared to those fed 0.5% extract and above. High protein was observed in fish fed with teste diet. study has revealed the ability of extracts from guava leaf to reduce pathogenic bacteria in the gut of Oreochromis niloticus and improve protein deposition in the flesh.