Recruitment-driven fish production in two regions where fish biomass has drastically declined

Abstract Catches have remained relatively high in the Gulf of Thailand and Bohai Sea, China, despite severe biomass declines (around 95%) evidenced by fishery-independent surveys. Such production at very low stock sizes is not predicted simple-surplus theory, but can be explained age-structured models that predict recruitment rates even when per recruit (BPR) has been drastically reduced. Recruitment reconstructed estimating changes over time BPR, for alternative assumptions about survey catchability, growth, mortality rates. These reconstructions indicate likely decreases due to fishing rates, imply total stable time, with catch consisting largely new recruits making up most biomass. considerations may apply numerous areas east southeast Asia where coastal trawlers used produce animal feeds, notably aquaculture.