Changes in the multi-species marine invertebrate fishery production in Bolinao, Pangasinan, northwestern Philippines after 30 years (1992–2023)

Marine invertebrates, many of which are gleaned, are part of the regular diet and provide income to rural coastal households in Bolinao, Pangasinan in northwestern Luzon, Philippines. A four-month daily market survey was conducted from February–May 2023 and compared with market data in 1992–1993 to determine changes in species composition, volume and estimated value after 30 years. A total of 63 species were recorded, but species composition varied between the two surveys. The relative abundance of wild-caught and cultured invertebrates increased but that of gleaned species decreased in 2023. Invertebrates sold in the local market in February–May 2023 reached a volume of 30.8 MT worth ∼Php 6 million (USD 108,635). The annual volume was estimated at 76.9 MT worth ∼Php 14.9 million (USD 271,587). This does not include the amount directly consumed by fisher households and high-value species (e.g., sea cucumbers, sea urchin roe, lobsters) transported to outside markets. Comparison of production data suggests 61.4 % decline in the volume of crustaceans and mollusks, corresponding to 17.8 % decrease in value. Several gastropods, bivalves and crustaceans are no longer collected in some sites. The decline in production in some sites could be attributed to overfishing, environmental degradation and recent coastal development projects. Local tourism and improved roads to outside markets may have also influenced the decrease in the volume sold in the local market. To sustainably utilize invertebrate resources, fisheries management must be implemented, especially in areas with high invertebrate production but vulnerable to environmental degradation.