Stock-recruitment relationships and recruitment patterns for forage fish stocks

Stock-recruitment data for 28 anchovy, herring, mackerel, sardine, and Spanish sardine stocks worldwide were examined for density-dependent effects on recruitment and for recruitment patterns. Per capita recruitment was significantly related to spawning biomass for about 90% of the stocks; year-class strengths were not statistically associated with spawning biomasses under observed ranges for over a half of the stocks. Close to a half of the stocks demonstrated compensatory, dome-shaped, or asymptotic S-R curves; poor year classes were more likely related to low spawning stocks. Positive correlations of year-class strengths were generally found among the geographically close neighboring stocks.