Little information is available concerning the seasonal demographics of marine migrating Alewife Alosa pseudoharengus and Blueback Herring A. aestivalis, reported in commercial fisheries as “gaspereau” in Canada and “river herring” in the USA. Once adults and age‐0 juveniles depart from coastal spawning rivers, they migrate along the North American Atlantic coast and are difficult to access for scientific analysis. During June–October 1985, a total of 3,785 Alewife and 2,343 Blueback Herring were examined for length, sex, and gonadal stage from commercial intertidal fishing weirs in Minas Basin and Cobequid Bay, Bay of Fundy, Nova Scotia. Of these, 999 adults were subsampled for total weight and body cavity fat deposits. Both species first appeared in the weirs during June, when Blueback Herring generally dominated catches. By July, catches were evenly divided between the two species, and Alewife dominated after mid‐August. Most adults were mature, and there was no discernable sex ratio pattern during the sampling period. Sampled fish exhibited abrupt changes in length, gonadal stage, condition factor, and abdominal wall and visceral mesentery fat deposits in relation to season (week), moon phase, and time of low tide. Sudden shifts in average lengths and fat deposits suggested that migrating Alewife were from different stocks. For Blueback Herring, the condition and status of fat deposits during June suggested that they were probably long‐distance adult migrators. Blueback Herring in Cobequid Bay weirs during July were probably from local stocks. Results from a total of 12,422 tagged adults that were released in Minas Basin and Cobequid Bay during 1985 supported these findings. We propose that shifts in condition and fat deposits can be used to estimate migration distance, discriminating among local, regional, and long‐distance movements.

中文翻译：

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加拿大芬迪内湾潮间带捕获的Alewife和蓝鲱鱼鲱鱼显示季节性人口特征，表明有多个迁徙种群

关于海洋迁徙Alewife Alosa pseudoharengus和Blueback Herring Aestivalis的季节性人口统计信息很少。据商业渔业报道，在加拿大被称为“ gaspereau”，在美国被称为“河鲱”。一旦成年和0岁以下的青少年从沿海产卵河出发，它们便会沿着北美大西洋沿岸迁移，并且难以进行科学分析。1985年6月至10月，在新斯科舍省米纳斯盆地和芬贝湾的Cobequid湾的商业潮间带捕鱼堰中检查了3,785头Alewife和2,343蓝背鲱鱼的长度，性别和性腺阶段。其中，对999名成年人进行了总体重和体腔脂肪沉积的二次抽样。这两种物种在六月期间首次出现在堰坝中，当时蓝背鲱鱼通常占主导地位。到7月，渔获物在两个物种之间平均分配，而Alewife在8月中旬之后占主导地位。大多数成年人都成熟了 在抽样期间，没有明显的性别比例模式。取样的鱼类显示出与季节（周），月相和退潮时间有关的长度，性腺阶段，条件因素以及腹壁和内脏肠系膜脂肪沉积的突然变化。平均长度的突然变化和脂肪沉积表明，迁徙的Alewife来自不同的种群。对于蓝鲱鱼来说，6月份的脂肪沉积状况和状况表明它们可能是长途成年移民。7月在Cobequid湾堰中的蓝鲱鱼可能来自当地股票。1985年在Minas盆地和Cobequid海湾释放的总共12,422例带标签的成年人的结果支持了这些发现。我们建议条件变化和脂肪沉积可用于估算迁移距离，