Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona, Barcelona, Spain; Institut de Recerca de la Biodiversitat (IRBio), University of Barcelona, Barcelona, Spain.
Université de Pau et des Pays de l'Adour, E2S UPPA, CNRS, IPREM, Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et les Matériaux, Pau, France.
Environ Pollut. 2024 Apr 15;347:123739. doi: 10.1016/j.envpol.2024.123739. Epub 2024 Mar 6.
Mercury (Hg) is a global pollutant, which particularly affects aquatic ecosystems, both marine and freshwater. Top-predators depending on these environments, such as seabirds, are regarded as suitable bioindicators of Hg pollution. In the Ebro Delta (NE Iberian Peninsula), legacy Hg pollution from a chlor-alkali industry operating in Flix and located ca. 100 km upstream of the Ebro River mouth has been impacting the delta environment and the neighboring coastal area. Furthermore, levels of Hg in the biota of the Mediterranean Sea are known to be high compared to other marine areas. In this work we used a Hg stable isotopes approach in feathers to understand the processes leading to different Hg concentrations in three Laridae species breeding in sympatry in the area (Audouin's gull Ichthyaetus audouinii, black-headed gull Chroicocephalus ridibundus, common tern Sterna hirundo). These species have distinct trophic ecologies, exhibiting a differential use of marine resources and freshwater resources (i.e., rice paddies prey). Moreover, for Audouin's gull, in which in the Ebro Delta colony temporal differences in Hg levels were documented previously, we used Hg stable isotopes to understand the impact of anthropogenic activities on Hg levels in the colony over time. Hg stable isotopes differentiated the three Laridae species according to their trophic ecologies. Furthermore, for Audouin's gull we observed temporal variations in Hg isotopic signatures possibly owing to anthropogenic-derived pollution in the Ebro Delta. To the best of our knowledge this is the first time Hg stable isotopes have been reported in seabirds from the NW Mediterranean.
汞（Hg）是一种全球性污染物，尤其会对海洋和淡水生态系统造成影响。以这些环境为食的顶级捕食者，如海鸟，被认为是汞污染的合适生物标志物。在埃布罗三角洲（伊比利亚半岛东北部），由于距离埃布罗河口上游约 100 公里的弗利克斯氯碱工业运营而产生的汞污染遗留问题一直影响着三角洲环境和邻近的沿海地区。此外，与其他海洋区域相比，地中海生物体内的汞含量已知较高。在这项工作中，我们使用羽毛中的汞稳定同位素方法来了解导致在该地区同域繁殖的三种鸥科物种（鸥 Ichthyaetus audouinii、红嘴鸥 Chroicocephalus ridibundus、普通燕鸥 Sterna hirundo）体内不同汞浓度的过程。这些物种具有不同的营养生态，表现出对海洋资源和淡水资源（即稻田猎物）的不同利用。此外，对于鸥，我们之前曾记录过埃布罗三角洲群体中汞水平的时间差异，我们使用汞稳定同位素来了解人为活动对该群体中汞水平随时间变化的影响。汞稳定同位素根据三种鸥科物种的营养生态进行了区分。此外，对于鸥，我们观察到汞同位素特征可能存在时间变化，这可能是由于埃布罗三角洲的人为污染所致。据我们所知，这是首次在西北地中海的海鸟中报告汞稳定同位素。
