Abstract Archaeological sites on the coast of Tierra del Fuego, Argentina, provide a biogeochemical record that can inform us about those ecological dynamics. An abundance of southern fur seal (Arctocephalus australis) and southern sea lion (Otaria flavescens) remains provide a valuable resource to reconstruct ancient and modern food webs. To quantify ecological relationships, we measured bulk stable isotope ratios from bone collagen in otariids and other associated animals, several of which are potential otariid prey. Variations in bulk stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) are linked to potential dietary differences and habitat specialization between coastal areas or the open ocean in populations ranging in age from 7000 cal. Years BP to modern. We observed increases in the variability of these isotopic compositions over time, which suggests a diversity in the diets and habitats of otariids. Shifts in marine food webs occurred during the transition from subsistence hunting of otariids to industrial hunting and expanded human influence. We conclude that direct human influences, such as hunting and habitat alteration, were the major drivers of ecological change in southern South American marine ecosystems.

中文翻译：

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火地岛人类剥削的鳍足类动物的时间和种群趋势

摘要 阿根廷火地岛海岸的考古遗址提供了生物地球化学记录，可以让我们了解这些生态动态。大量的南方海狗 (Arctocephalus australis) 和南方海狮 (Otaria flavescens) 遗骸为重建古代和现代食物网提供了宝贵的资源。为了量化生态关系，我们测量了 otariids 和其他相关动物中骨胶原的体积稳定同位素比率，其中一些是潜在的 otariid 猎物。碳 (δ13C) 和氮 (δ15N) 的整体稳定同位素比率的变化与沿海地区或公海之间的潜在饮食差异和栖息地专业化有关，这些人群的年龄范围为 7000 卡路里。年BP到现代。我们观察到随着时间的推移这些同位素组成的变异性增加，这表明 otariids 的饮食和栖息地的多样性。海洋食物网的转变发生在从耳目动物的生存狩猎到工业狩猎以及人类影响扩大的过渡期间。我们得出结论，人类的直接影响，如狩猎和栖息地改变，是南美南部海洋生态系统生态变化的主要驱动因素。