Impact of Climatic Factors on Early Life Stages of Atlantic Mackerel, Scomber Scombrus, L.: An Application of Meteorological Data to a Fishery Problem

Abstract

Climate influences the abundance of Atlantic mackerel, Scomberscombrus, in several ways. In the southerncontingent, the timing of the spawning migration is functionally related to sea surface temperature. Wefound this climatic linkage is also significantly related to the abundance of mackerel entering the northwesternAtlantic fishery the following year. In the Middle Atlantic Bight, cooler spring water temperatures duringa spawning season are associated with greater recruitment the following year. Mackerel spawn in nearshoresurface waters at a time when winds frequently are offshore, but survival should be favored by onshore drift.Egg and larval drift over 14 day periods, at 13 locations in the Middle Atlantic Bight were simulated forspawning seasons preceding five "strong" and three "weak" recruitment years. The results of these studiesdemonstrate that the net and offshore distances transported in "strong" versus "weak" years were notsignificantly different. When the outlier year 1967, which preceded the record strong recruitment in 1968,is examined with respect to the sea surface temperature as an indication of delayed spawning, it appears thatwind-driven transport toward shore may have been an instrumental variable.