Ministry of Education Key Laboratory for Ecology of Tropical Islands, Key Laboratory of Tropical Animal and Plant Ecology of Hainan Province, College of Life Sciences, Hainan Normal University, Haikou, 571158, China.
Environ Sci Pollut Res Int. 2022 Oct;29(50):76394-76403. doi: 10.1007/s11356-022-21057-5. Epub 2022 Jun 6.
Trace element pollution is a potential threat to the reproduction of sea turtles. Hainan Island was previously the most important nesting ground of green sea turtles in China before they disappeared approximately 36 years ago. The Chinese government has encouraged restoration work on historical nesting grounds, and it is necessary to evaluate the status of these sites before conducting habitat restoration. This study analyzed the concentrations of seven trace elements in the surface sediments of 13 historical nesting grounds in Hainan. The average concentrations were 19.47 (Cr), 4.67 (Ni), 6.99 (Cu), 0.08 (Cd), 16.68 (Pb), 0.02 (Hg), and 5.27 (As) mg/kg, which were lower than the first-grade limit values of the GB (18668-2002) national standard in China. The concentrations were close to the background value, except for the relatively high Cd value. The potential ecological risk was ranked as Cd > Hg > As > Cu > Pb > Cr. The spatial distribution of trace element contamination in Hainan was uneven, with high potential ecological risk levels of Cd and Hg contamination in Longwan'gang, Shimeiwan, Yazhou Qu, and Fushicun. Marine mariculture, wastewater discharge, and fishing boats are the main sources of trace element contamination in Hainan. We recommend strengthening the control of Hg and Cd contamination sources, monitoring trace elements in relevant/interest areas, and the environmental protection department should curb local residents from directly discharging mariculture wastewater and domestic sewage into the sea.
微量元素污染对海龟繁殖构成潜在威胁。海南岛曾是中国绿海龟最重要的筑巢地，但在大约 36 年前，绿海龟已消失不见。中国政府鼓励对历史筑巢地进行恢复工作，在进行栖息地恢复之前，有必要评估这些地点的现状。本研究分析了海南 13 个历史筑巢地表层沉积物中 7 种微量元素的浓度。平均值分别为 19.47（Cr）、4.67（Ni）、6.99（Cu）、0.08（Cd）、16.68（Pb）、0.02（Hg）和 5.27（As）mg/kg，均低于中国《土壤环境质量农用地土壤污染风险管控标准（试行）》（GB18668-2002）一级标准限值。浓度接近背景值，除 Cd 值相对较高外。潜在生态风险为 Cd＞Hg＞As＞Cu＞Pb＞Cr。海南的微量元素污染空间分布不均匀，龙湾港、石梅湾、崖州湾和福山镇的 Cd 和 Hg 污染具有较高的潜在生态风险水平。海洋养殖业、废水排放和渔船是海南微量元素污染的主要来源。我们建议加强对 Hg 和 Cd 污染来源的控制，监测相关/关注地区的微量元素，并要求环境保护部门遏制当地居民直接将养殖废水和生活污水排入大海。
