Population dynamics and biological characteristics of the Newfoundland west coast herring stock

Abstract

Atlantic herring (Clupea harengus harengus L.) occurring along the west coast of Newfoundland were examined. Based on tagging results and spacing type (spring-spawners and autumn-spawners) composition a fisheries management unit encompassing the area from Cape Anguille to Cape Norman was proposed. Several spawning areas have been identified in this area indicating that there are several herring populations in the area such that the fishery exploits a stock-complex. Several biological characteristics including maturity rate, growth and feeding were examined. A comparison of growth rates from samples taken at two spawning sites and from the fall fishery did not indicate any differences and the populations were, therefore, treated as a unit stock for an analysis of its population dynamics. These analyses indicate that recruitment in recent years has generally been poor particularly among autumn-spawners which have steadily declined in abundance during the period covered by the analysis (1966-78). Recruitment to the spring-spawning component has been poor with the exception of the exceptionally strong 1968 year-class and the moderately strong 1974 year-class., However, no stock and recruit relationship could be established. In terms of F₀₋₁ management strategy the stock is currently under exploited.