California Current - Fish Production and Growth

Fish Production and Growth

The California Current produces an abundance of sardines, anchovies, hake, jack mackerel, and mackerel (Mann and Lazier, 2006). An abundance of these fish species is a common feature of eastern boundary currents. Sardines in particular were heavily fished from 1916 - 1967. This led to the California state legislature to impose a suspension on sardine fishing in 1967 (Mann and Lazier, 2006). The largest stocks of both sardine and anchovy spawn in the Southern California Bight. Sardines in the California Current are divisible into four stocks and anchovies in this current have several subpopulations as well (Mann and Lazier, 2006). The California Bight is a region of relatively weak upwelling (and thus weak phytoplankton production) compared to the greater California Current. From these observations, we see that fish often choose to spawn in areas where Ekman transport will not carry their eggs too far offshore. Many fish species avoid spawning in areas of strong upwelling. Although upwelling and the subsequent high biological productivity produces optimal conditions for the growth of juvenile and adult sardines, the absence of strong upwelling in late winter and early spring (such as that found in the California Bight) is what creates optimum conditions for the survival of fish larvae (Mann and Lazier, 2006). Once anchovy and sardine larvae have spent a significant amount of time in waters free of strong upwelling and mixing (i.e. The California Bight), they migrate (as juveniles) toward areas of great upwelling (i.e. The California Current proper). There the juveniles can take advantage of the high biological productivity and maximize their growth rate.