The codevelopment of coastal fisheries monitoring methods to support local management

Abstract

Small-scale fisheries across the globe provide critical food security, livelihoods, and human well-being, but are threatened by a combination of local and global stressors, including overexploitation, pollution, and climate change. Participatory approaches to management, especially those that incorporate local communities and customary knowledge can provide meaningful biological information that supports sustainable fisheries management and builds local adaptive capacity to changing ocean conditions. Through a collaboration between fishers, scientists, NGOs, and regulating agencies, we developed a low-cost, low-tech method to assess the seasonal spawning peaks, lunar spawning cycles, and size at maturity (L50) for key targeted reef fish, combining traditional knowledge and practice with modern scientific approaches, including gonadosomatic index (GSI) and histology. Two years of community-based monitoring resulted in data from 57 species and 15 families of reef and nearshore fishes (n = 2595), with detailed information for 10 species at 4 locations across the Hawaiian Islands. Comparisons between community-collected GSI data and scientifically (histologically) assessed spawning cycles and size at reproductive maturity produced similar results suggesting that these approaches can be applied in data-poor fisheries to assess spawning seasons and size at maturity (L50), both of which are critical needs for effective fisheries management. Semistructured surveys revealed a large body of local knowledge on spawning times and harvest practices based on allowing spawning to occur before harvesting and protecting small and large size classes, but little evidence that fishers understand temporal patterns of spawning. This suggests that monitoring methods that fill key gaps such as this and are congruent with these local knowledge systems and customary harvest practices may be key for local stewardship and adaptive management.