Recruitment Patterns in Northwest Atlantic Fish Stocks

Abstract

By analysing recruitment time series for 14 stocks of northwest Atlantic fish, I have found consistent positive correlations in recruitment among stocks within such species as cod (Gadus morhua), haddock (Melanogrammus aeglefinus), and herring (Clupea harengus). Significant positive correlations are also often found in recruitment among demersal, offshore-spawning species (cod, haddock, and redfish (Sebastes spp.)), and recruitment in these groups tends to be negatively correlated with that of pelagic species, which spawn inshore (herring) or in restricted waters (mackerel (Scomber scombrus)). These patterns emerge as well from a principal component (PC) analysis of the recruitment data. Three dominant patterns (PC 1–3) explain 78% of the variance of the data set. I suggest that the spatial extent of these patterns, which span the region from west Greenland to Georges Bank, indicates that large-scale physical forcing, rather than local biological interactions, predominantly regulates recruitment to northwest Atlantic fisheries.