Pacific herring, Clupea pallasi, recruitment in the Bering Sea and north-east Pacific Ocean, I: relationships among different populations

We examined recruitment and average weight-at-age rime series for Pacific h erring (Clupea pallasi) populations from the Bering Sea and north-east Paci fic Ocean to determine similarities. Statistical correlation and multivaria te clustering methods indicated Pacific herring populations form large-scal e groups. Large year classes occur synchronously among several Pacific herr ing populations. Multivariate cluster analyses of recruitment and weight-at -age data indicated that Bering Sea herring populations are distinct from n orth-east Pacific Ocean populations. Within the NE Pacific Ocean, there app ear to be three groups of herring populations: a British Columbia group, a south-east Alaska coastal group, and an outer Gulf of Alaska group. Jackkni fe and randomization tests indicate these groups are robust and not the res ult of random chance. Deviations from observed herring population groups we re examined for indications of anthropogenic perturbations. The Prince Will iam Sound herring populations did not show any strong deviations correspond ing to the oil spill of 1989. There might not yet be enough data since the spill to detect changes in the recruitment or weight-at-age data since that time, particularly if oil spill effects were concentrated on the early lif e history stages.