University of Coimbra, Marine and Environmental Sciences Centre, Department of Life Sciences, Calçada Martim de Freitas, 3000-456, Coimbra, Portugal.
MARE - Marine and Environmental Sciences Centre, ESTM, Politécnico de Leiria, 2520-641, Peniche, Portugal.
Environ Pollut. 2022 Jan 1;292(Pt B):118451. doi: 10.1016/j.envpol.2021.118451. Epub 2021 Nov 2.
The assessment of contaminant exposure in marine organisms often focuses on the most toxic chemical elements from upper trophic level species. Information on mid-trophic level species and particularly on potentially less harmful elements is lacking. Additionally, microplastics have been considered emergent contaminants in aquatic environments which have not been extensively studied in species from mid-trophic levels in food chains. This study aims to contribute to an overall assessment of environmental impacts of such chemicals in a community of small pelagic fish in the North Atlantic. The concentrations of 16 chemical elements, rarely simultaneously quantified (including minerals, trace elements and heavy metals), and the presence of microplastics were analysed in sardines (Sardina pilchardus) and mackerels (Scomber spp. and Trachurus trachurus) sampled along the Portuguese coast. Biochemical stress assessments and stable isotope analyses were also performed. The chemical element concentrations in S. pilchardus, T. trachurus, and Scomber spp. were relatively low and lower than the levels reported for the same species in the North Atlantic and adjacent areas. No clear relationships were found between chemical elements and oxidative damage in fish. However, the concentration of several chemical elements showed differences among species, being related with the species' habitat use, trophic niches, and specific feeding strategies. The presence of plastic pieces in the stomachs of 29% of the sampled fishes is particularly concerning, as these small pelagic fish from mid-trophic levels compose a significant part of the diet of humans and other top predators. This study highlights the importance of multidisciplinary approaches focusing on the individual, including position data, stable isotopes, and oxidative stress biomarkers as complementary tools in contamination assessment of the marine mid-trophic levels in food chains.
海洋生物中污染物暴露的评估通常集中在来自上层营养级物种的最有毒化学元素上。关于中层营养级物种的信息，特别是关于潜在危害较小的元素的信息，还很缺乏。此外，微塑料被认为是水生环境中的新兴污染物，在食物链中的中层营养级物种中尚未得到广泛研究。本研究旨在为北大西洋小型洄游鱼类群落中此类化学物质的环境影响进行综合评估。本研究分析了沙丁鱼（Sardina pilchardus）和鲐鱼（Scomber spp.和Trachurus trachurus）中 16 种化学元素（包括矿物质、微量元素和重金属）的浓度，以及微塑料的存在，这些元素很少同时被量化。还进行了生化应激评估和稳定同位素分析。S. pilchardus、T. trachurus 和 Scomber spp.中的化学元素浓度相对较低，低于北大西洋和邻近地区同一物种的报告水平。在鱼类中，化学元素与氧化损伤之间没有发现明显的关系。然而，几种化学元素的浓度在不同物种之间存在差异，这与物种的栖息地利用、营养位和特定的摄食策略有关。在 29%采样鱼类的胃中发现了塑料碎片，这尤其令人担忧，因为这些来自中层营养级的小型洄游鱼类是人类和其他顶级捕食者饮食的重要组成部分。本研究强调了采用多学科方法关注个体的重要性，包括位置数据、稳定同位素和氧化应激生物标志物，作为食物链中海洋中层营养级污染评估的补充工具。
