Abstract The franciscana (Pontoporia blainvillei) is a coastal dolphin endemic to the south-western Atlantic Ocean. Incidental captures in fishing gillnets are the greatest conservation concern for this species. The present study examines the biophysical interactions between the franciscana prey composition and the marine environment. The feeding regime of franciscana was investigated from stomach contents of incidentally caught animals along the southern Brazilian coast. The characteristics of the franciscana habitat may reveal potential factors affecting the distribution and abundance of marine species, thus the franciscana prey (species number and size) was treated as a function of the oceanographic variables (sea surface temperature and chlorophyll-a), and the spatial (latitude and water depth), and temporal (season) parameters, through Linear and Generalized Linear Models (LM and GLM). Season and latitude were important predictors of the franciscana diet, followed by water temperature and depth. Chla parameter only influenced one fish species and therefore was not useful as an explanatory variable for our study. The influence of the predictors and prey distribution of the franciscana diet are similar to that found in the habitat by research cruise data. Some structures analysed (e.g. squid beaks) may remain longer in the stomachs. Therefore, the findings not only suggest a fairly opportunistic behaviour but it is likely that franciscana may occupy, and possibly for long periods, small spatial ranges. This behaviour might be a strategy for minimizing energetic costs by restricting movements to short distance areas, which can be an important factor for conservation planning along the southern Brazilian coast.

中文翻译：

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推动巴西南部海岸弗朗西斯卡纳海豚觅食生态的海洋学过程

摘要 franciscana (Pontoporia blainvillei) 是大西洋西南部特有的一种沿海海豚。渔刺网中的意外捕获是该物种最大的保护问题。本研究考察了 franciscana 猎物成分与海洋环境之间的生物物理相互作用。从巴西南部海岸偶然捕获的动物的胃内容物中研究了 franciscana 的喂养方式。franciscana 栖息地的特征可能揭示影响海洋物种分布和丰度的潜在因素，因此 franciscana 猎物（物种数量和大小）被视为海洋变量（海面温度和叶绿素 a）的函数，而空间（纬度和水深）和时间（季节）参数，通过线性和广义线性模型（LM 和 GLM）。季节和纬度是弗朗西斯卡纳饮食的重要预测因素，其次是水温和深度。Chla 参数仅影响一种鱼类，因此不能作为我们研究的解释变量。franciscana 饮食的预测因子和猎物分布的影响类似于研究巡航数据在栖息地中发现的影响。一些被分析的结构（例如鱿鱼喙）可能会在胃中停留更长时间。因此，研究结果不仅表明了一种相当机会主义的行为，而且 franciscana 可能占据，并且可能长期占据小空间范围。这种行为可能是通过将运动限制在短距离区域来最小化能量成本的策略，