Abstract

The Northwest Atlantic mackerel (Scomber scombrus) population is comprised of northern and southern contingents, each with distinct natal regions in the United States and Canada. We tested hypotheses on natal origin and contingent mixing by analysing natal otolith δ¹⁸O values, evaluating the approach through an out-group comparison with the Northeast Atlantic population. Otolith δ¹⁸O values varied according to expectations between the Northeast (higher) and the Northwest (lower) Atlantic basins, and between contingents within the Northwest Atlantic stock, although contingent differences varied between years. Most adults (age-3+ years) sampled from US waters (1999–2003) represented the northern contingent (Canadian spawning site). The confirmation of the seasonal mixing of older and larger fish between the two contingents provides support and justification for the development of bi-national (United States–Canada) assessment and management of Northwest Atlantic mackerel.

中文翻译：

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用耳石δ18O组成评估西北大西洋鲭鱼的种群结构

摘要

西北大西洋鲭鱼（Scomber scombrus）的种群由北部和南部的特遣队组成，在美国和加拿大每个人都有不同的出生地。我们通过分析产后耳石δ测试的产后来源和队伍混合假设^18个O值，评估通过与东北大西洋人口外群比较接近。耳石δ ¹⁸O值根据东北部（较高）和西北部（较低）盆地之间以及西北大西洋种群内各特遣队之间的期望而变化，尽管各年之间的特异差异也有所不同。从美国水域采样的大多数成年人（3岁以上）（1999-2003年）代表北部特遣队（加拿大产卵场）。确认两个特遣队中较大和较大鱼类的季节性混合，为制定西北大西洋鲭鱼进行双国（美国-加拿大）评估和管理提供了支持和理由。