UNDERSTANDING AQUACULTURE BIOSECURITY TO IMPROVE CATFISH DISEASE MANAGEMENT IN OGUN AND DELTA STATES, NIGERIA

Nigeria is now one of Africa’s largest aquaculture producers with catfish and tilapia being the dominant farmed fish. Yet the lack of a clear aquatic animal health strategy has resulted in substantial disease-related production losses. There is little or no biosecurity management practiced at the production level, except by a few large-scale commercial farms. This study aimed to better understand epidemiology and risk factors leading to mortality and production losses of catfish in a regional model using Ogun and Delta States. WorldFish and partners developed a Fish Epidemiology and Health Economics digital survey tool to collect baseline data from 399 farms.

Descriptive statistics were classified by state identity and unusual level of farm mortality, were calculated for production system, biosecurity, management, and other potential risk factors on 220 farms, which only raised table size catfish. Mixed model logistic regression was used to assess the association between the occurrence of high mortality and these potential risk factors. State identity was included as a random effect.

Key findings:

• A significant association between unusual farm mortality and state identity wasn’t detected (p=0.314) but it was included as a random effect to account for it as a source of variation.
• 10.45% farms experienced unusual fish mortality
• Farms having unusual fish mortality (n=23) had a higher baseline mortality compared to farms without unusual fish mortality (n=197), 15.1% and 6.6% respectively
• No biosecurity procedures were followed at stocking (96.8%), or between production cycles (30.9%)
• 14.6% of farm kept paper records of mortality losses, while other farms estimated losses from memory
• Farms that dried ponds between productions had less unusual mortality (8.47%) compared to farms that didn’t (11.18% unusual mortality) but the difference was not significant (p=0.856)
• Farms that did not share equipment/staff with other farms had lower unusual mortality (8.28%) compared to farms that shared with one (15.38% or two or more farms 16.00%) but the differences were not significant (p=0.443)
• Farms that added fish to the stock after the main stocking event reported higher unusual mortality (42.86%) than farms that did not (only 9.39% unusual mortality) (p=0.045)
• Only 1.36% of farms reported using the services of a veterinarian

Conclusions:

Biosecurity can be improved. Risk factors analysis allow a better understanding of the industry and can further inform development of interventions in the form of better management practices, guidelines for national aquatic health strategies and farm level biosecurity plans for sustainable aquaculture in the targeted regions.