The northwest Atlantic subspecies of gray seal (Halicheorus grypus grypus) has been increasing for more than a half century and has reestablished breeding colonies in Canadian and US waters. In 2016, visual, oblique, and vertical large‐format digital photographic surveys were conducted at all known breeding colonies in the northwest Atlantic. Total pup production in the northwest Atlantic was estimated to be 109,000 (SE = 17,500) pups. At 87,500 (SE = 15,100) pups, Sable Island accounts for 80% of total pup production. Regional differences in pup production trends are evident. Pup production in the Gulf of St. Lawrence and along the eastern shore of Nova Scotia has been relatively stable. Since 2004, the rate of increase in pup production at Sable Island has slowed to about 5%–7% per year, while the newer colonies in southwest Nova Scotia and the northeastern United States are increasing rapidly. In 2016, the Muskeget Island (MA) breeding colony produced 3,900 (SE = 200) pups, making it the third largest breeding colony in the northwest Atlantic. This southward shift in production may reflect climate‐mediated changes in population growth as well as reestablishment of colonies throughout the former range associated with increased protection.

中文翻译：

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在西北大西洋增加种群中灰海豹（Halichoerus grypus）幼崽生产的相反趋势

西北大西洋灰海豹（Halicheorus grypus grypus）亚种已经增加了半个多世纪，并在加拿大和美国水域重新建立了繁殖种群。2016年，在西北大西洋所有已知的繁殖地进行了可视，倾斜和垂直大型数码照片调查。据估计，西北大西洋的幼崽总产量为109,000（SE = 17,500）幼崽。在87,500（SE= 15,100头幼崽），黑貂岛占幼崽总产量的80％。幼犬生产趋势的区域差异是显而易见的。圣劳伦斯湾和新斯科舍省东海岸的幼仔生产相对稳定。自2004年以来，黑貂岛幼崽产量的增长速度已降至每年5％–7％左右，而新斯科舍省西南部和美国东北部的新殖民地正在迅速增长。2016年，马斯基盖特岛（MA）的繁殖地产生了3,900只（SE = 200）幼崽，使其成为西北大西洋地区第三大繁殖地。生产的这种向南转移可能反映了气候介导的人口增长变化以及在与保护措施相关的整个先前范围内的殖民地重建。