We investigated the habitat use and feeding ecology of 10 cetacean species encountered along the south-eastern coast of Brazil (24–26°S) using carbon (δ13C) and nitrogen (δ15N) stable isotopes. Hierarchical cluster analysis distinguished two main groups based on their isotopic patterns. One group included migratory baleen whales (Megaptera novaeangliae and Eubalaena australis) with the lowest δ13C and δ15N values, reflecting baseline isotopic values of their Subantarctic feeding grounds and consumption of lower trophic level prey. Resident species and those occasionally occurring in Brazilian coastal waters highly differed from the migratory whales in their isotopic values. In this group, Tursiops truncatus had the highest δ13C and δ15N values, indicating coastal habits and relatively higher trophic position. Similar δ13C values were observed in Sotalia guianensis, Pontoporia blainvillei, Orcinus orca and Steno bredanensis. However, the former two species had lower δ15N values than the latter two, indicating different trophic positions. The relatively lower δ13C values observed in Stenella frontalis suggest greater influence of pelagic prey in their diet. Furthermore, the lower δ13C values observed in Delphinus delphis and Balaenoptera edeni were associated with upwelling events that occur along the region, affecting the isotopic values of their main prey. Juvenile M. novaeangliae had higher δ13C and δ15N than the adults, which may indicate feeding in areas with different isoscapes and consumption of pelagic schooling fish with relatively higher trophic levels than krill. This study provides preliminary information that are useful to understand the habitat use and coexistence of cetacean species occurring in south-eastern Brazil.

中文翻译：

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通过皮肤 δ13C 和 δ15N 评估在巴西东南部沿海水域采样的鲸类的营养生态学和觅食区

我们使用碳研究了在巴西东南海岸（24-26°S）遇到的 10 种鲸目动物的栖息地利用和摄食生态学（δ13C) 和氮气 (δ15N) 稳定同位素。层次聚类分析根据同位素模式区分了两个主要组。一组包括迁徙须鲸（巨翅目和南极鱼) 最低δ13C 和δ15N 值，反映其亚南极觅食地的基线同位素值和低营养级猎物的消耗。常驻物种和偶尔出现在巴西沿海水域的物种在同位素值上与迁徙的鲸鱼有很大不同。在这个组中，截尾草有最高的δ13C 和δ15N 值，表明沿海习性和相对较高的营养位置。相似的δ13C 值观察到贵安山葵,黑斑病,逆戟鲸和布列丹牛耳草. 然而，前两个物种的δ15N值大于后两者，表明不同的营养位置。相对较低δ13观察到的 C 值额角小球藻表明远洋猎物对其饮食的影响更大。此外，较低的δ13观察到的 C 值海豚和长翅目与沿该地区发生的上升流事件有关，影响其主要猎物的同位素值。少年M. novaeangliae有更高的δ13C 和δ15N 高于成鱼，这可能表明在不同等景观的地区摄食和食用营养水平高于磷虾的远洋群落鱼。本研究提供了有助于了解巴西东南部鲸类物种栖息地利用和共存的初步信息。