Integrated Pest Management in Marine Aquaculture Cages in Coastal Rivers State

Parasitic and bacterial diseases represent major constraints to cage aquaculture productivity in Nigerian coastal waters, and the overuse of chemotherapeutic agents in disease management poses serious environmental and food safety risks. This study developed and assessed an integrated pest management approach for marine cage aquaculture operations in coastal Rivers State. A participatory action research framework was adopted, involving 14 cage fish farmers grouped into control and intervention cohorts. The intervention cohort received training on IPM protocols encompassing biosecurity practices, prophylactic vaccination, stress reduction husbandry, herbal plant extract treatments, and structured chemotherapy use as a last resort. Fish health monitoring was conducted biweekly through examination of 30 randomly selected fish per cage for external and internal parasite burdens, bacterial lesion signs, and mortality rates. Production performance including feed conversion ratio and growth rate were recorded over a 16-week trial period. Farms implementing IPM protocols achieved a 47 percent reduction in cumulative disease-related mortality compared to control farms. Chemical treatment frequency was reduced by 63 percent without adverse effects on production outcomes. Feed conversion ratio improved significantly in IPM farms, attributed to reduced disease-induced feed refusal. Ectoparasite burden on gill tissue was significantly lower in IPM cohort fish. Farmer adoption of biosecurity practices was rated as high by 79 percent of participants. The study recommends formalised IPM training as part of Rivers State aquaculture extension services. Keywords: integrated pest management, cage aquaculture, fish health, Rivers State, disease management.