The biological effect of fishing bans in tropical waters is considered. In the Philippines, the Samar Sea was closed to trawlers in November 1976; a fishery survey was carried out to monitor possible changes in the fish stocks. In spite of the ongoing activities of a few small trawlers, the biomass of fish in the Samar Sea increased constantly during the survey period. Thus, it is concluded that the imposition of a trawling ban is a suitable tool in tropical waters to protect the vital interests of the sustenance fishery by helping heavily exploited fish stocks to recover.