Centro de Investigación de Fauna Marina y Avistamiento de Cetáceos (CIFAMAC), Mejillones, Chile; Departamento de Ciencias Básicas, Facultad de Ciencias, Universidad Santo Tomás, Antofagasta, Chile.
Université de Brest, Muséum National d'Histoire Naturelle,CNRS, Sorbonne Université, ISYEB, F-29200 Brest, France.
Sci Total Environ. 2021 May 20;770:145259. doi: 10.1016/j.scitotenv.2021.145259. Epub 2021 Jan 21.
Long-finned pilot whales (LFPW) are cetaceans with strong social groups often involved in mass strandings worldwide. However, these beachings occur for reasons that are not fully understood. In 2016, 124 LFPW were stranded on the Chilean Patagonian islands, offering a unique opportunity to obtain crucial information on the ecology, biology, and genetics of this population. In addition, we examined whether persistent organic pollutants (POPs) and trace elements (TEs) were responsible for this mass mortality. Stable isotopes (δC & δN) and genetic analyses were used to reconstruct the trophic ecology, social structure, and kinship of LFPW and compared to POPs and TEs levels found in LFPW. Mitochondrial DNA analyses on 71 individuals identified four maternal lineages within the stranded LFPW. Of these animals, 32 individuals were analyzed for a suite of POPs, TEs, and lipid content in blubber. The highest levels were found for ΣDDXs (6 isomers) (542.46 ± 433.46 ng/g, lw) and for total Hg (2.79 ± 1.91 mg/kg, dw). However, concentrations found in these LFPW were lower than toxicity thresholds and those reported for LFPW stranded in other regions. Evidence was found of ΣDDX, Σ7PCBs, and Cd bioaccumulation and maternal transfer of POPs in mother/offspring groups. Nevertheless, no clear relationship between contaminant concentrations and LFPW mortality was established. Further research is still needed to assess LFPW populations including conservations status and exposure to chemicals in remote areas such as Patagonia.
长鳍领航鲸（LFPW）是具有强烈社会群体的鲸目动物，经常在全球范围内发生大规模搁浅事件。然而，这些搁浅事件的原因尚未完全了解。2016 年，124 头长鳍领航鲸在智利巴塔哥尼亚群岛搁浅，这为获取有关该种群生态学、生物学和遗传学的重要信息提供了独特的机会。此外，我们还研究了持久性有机污染物（POPs）和微量元素（TEs）是否是导致这次大规模死亡的原因。稳定同位素（δC 和 δN）和遗传分析用于重建长鳍领航鲸的营养生态、社会结构和亲缘关系，并与长鳍领航鲸体内的 POPs 和 TEs 水平进行比较。对 71 头搁浅的长鳍领航鲸进行的线粒体 DNA 分析确定了四个母系谱系。在这些动物中，32 头动物的鲸脂中分析了一系列 POPs、TEs 和脂质含量。ΣDDXs（6 种异构体）（542.46±433.46ng/g，lw）和总汞（2.79±1.91mg/kg，dw）的浓度最高。然而，这些长鳍领航鲸体内的浓度低于毒性阈值和其他地区搁浅的长鳍领航鲸的报告浓度。在母鲸/幼鲸群体中发现了 ΣDDX、Σ7PCBs 和 Cd 的生物积累以及 POPs 的母体转移的证据。然而，并未确定污染物浓度与长鳍领航鲸死亡率之间的明确关系。仍需要进一步研究，以评估包括保护状况和在偏远地区（如巴塔哥尼亚）接触化学物质在内的长鳍领航鲸种群。
