Castillo-Guerrero José Alfredo, González-Medina Erick, Piña-Ortiz Alberto, Betancourt-Lozano Miguel, García-Hernández Jaqueline, Hernández-Vázquez Salvador, Fernández Guillermo
Departamento de Estudios para el Desarrollo Sustentable de Zonas Costeras, Centro Universitario de la Costa Sur, Universidad de Guadalajara, San Patricio-Melaque, México.
Conservation Biology Research Group, Área de Zoología, Universidad de Extremadura, Madrid, España.
Ecotoxicology. 2025 May;34(4):522-538. doi: 10.1007/s10646-025-02853-4. Epub 2025 Jan 13.
Monitoring the dynamics of contaminants in ecosystems helps understand their potential effects. Seabirds have been used as biomonitors of marine ecosystems for this purpose. However, exposure and vulnerability to pollutants are understudied in tropical species, and the relationships between various pollutants and the trophic ecology of seabirds are poorly understood. In this study, we quantified mercury (Hg), lead (Pb), cadmium (Cd), and organochlorine pesticide (OC) concentrations in the blood of Laughing Gulls and Magnificent Frigatebirds breeding in Bahía Santa María, México. Using carbon and nitrogen isotopic ratios (δC and δN), we examined the interaction between contaminants and trophic ecology. Laughing Gulls exhibited higher concentrations of dichlorodiphenyltrichloroethane and its metabolites (ΣDDTs), endrins (ΣDrins), and chlordanes, while Magnificent Frigatebirds had elevated levels of Hg and hexachlorocyclohexane isomers (ΣHCHs). Both species displayed temporal and sex-related variations in isotopic signatures. Some blood pollutant concentrations in Laughing Gulls were explained by diet: ΣOCs in plasma were directly related to trophic levels, indicating biomagnification, whereas higher Hg levels were associated with changes in habitat use. In contrast, the differences in sex-related isotopic signatures in Magnificent Frigatebirds did not reflect pollutant accumulation patterns, possibly due to their opportunistic feeding habits.
监测生态系统中污染物的动态有助于了解其潜在影响。为此，海鸟已被用作海洋生态系统的生物监测指标。然而，热带物种对污染物的暴露和易感性研究不足，而且各种污染物与海鸟营养生态学之间的关系也知之甚少。在本研究中，我们对在墨西哥圣玛丽亚湾繁殖的笑鸥和华丽军舰鸟血液中的汞（Hg）、铅（Pb）、镉（Cd）和有机氯农药（OC）浓度进行了量化。利用碳和氮同位素比率（δC和δN），我们研究了污染物与营养生态学之间的相互作用。笑鸥体内的二氯二苯三氯乙烷及其代谢物（ΣDDTs）、异狄氏剂（ΣDrins）和氯丹浓度较高，而华丽军舰鸟体内的汞和六氯环己烷异构体（ΣHCHs）水平升高。两个物种的同位素特征均呈现出时间和性别相关的变化。笑鸥血液中的一些污染物浓度可由饮食来解释：血浆中的ΣOCs与营养级直接相关，表明存在生物放大作用，而较高的汞含量与栖息地利用的变化有关。相比之下，华丽军舰鸟性别相关的同位素特征差异并未反映出污染物积累模式，这可能是由于它们的机会主义觅食习性所致。
