The hull in-water cleaning (IWC) process creates chemical contaminants, including antifouling paint particle mixtures that are directly discharged into the coastal environment. Recent attention has also been paid to the international regulation of ship hull cleaning discharges in environmental media. However, few studies have investigated the adverse effects or toxic pathways on resident marine species. In this study, we evaluated the chemical concentration of IWC discharge in situ and its toxic effects on juvenile rockfish (Sebastes schlegeli), a major coastal fishery resource, using enzymatic and transcriptomic studies. Zinc (8.05 ± 0.96 to 189.96 ± 47.76 μg/L) was the most abundant substance in IWC discharge, followed by copper (0.87 ± 0.19 to 1.97 ± 0.60 μg/L). No mortality was observed after 7 days of exposure in any experimental group; however, reactive oxygen species and acetylcholinesterase activity varied in juvenile rockfish exposed to the highest concentration of IWC discharge (10-fold-diluted IWC discharge). The immune and detoxification systems in juvenile rockfish exposed to IWC discharge were also significantly affected in juvenile rockfish exposed to 10-fold-diluted IWC discharge (zinc: 189.96 ± 47.76 μg/L, copper: 1.97 ± 0.60 μg/L). The expression of genes related to oxidative stress, including Cu/Zn-SOD, GST, and CAT, increased significantly in fish in all the exposure groups. Specifically, brain transcriptomic analysis revealed disturbances in the nervous system and homeostatic processes. Although lethal toxicity was not significantly affected, these findings indicate the potential hazard posed by sub-lethal concentrations of IWC discharge to juvenile fish, which are at a high-level in the food chain. Our enzymatic and transcriptomic results showed that Zn-dominant IWC discharge exposure may cause neuronal and immune toxicity in marine fish species, providing relevant insights into the management of hull IWC discharge to protect coastal ecosystems against chemical contaminants.

中文翻译：

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船壳水中清洁排放物对幼鱼 （Sebastes schlegeli） 的酶和转录不利影响


船体水中清洁 （IWC） 工艺会产生化学污染物，包括直接排放到沿海环境中的防污漆颗粒混合物。最近，环境介质中船体清洁排放的国际法规也受到了关注。然而，很少有研究调查对常驻海洋物种的不利影响或毒性途径。在这项研究中，我们使用酶和转录组学研究评估了 IWC 原位排放的化学浓度及其对主要沿海渔业资源幼鱼 （Sebastes schlegeli） 的毒性影响。锌 （8.05 ± 0.96 至 189.96 ± 47.76 μg/L） 是 IWC 排放物中含量最高的物质，其次是铜 （0.87 ± 0.19 至 1.97 ± 0.60 μg/L）。在任何实验组中，暴露 7 天后均未观察到死亡率;然而，在暴露于最高浓度 IWC 排放物（10 倍稀释的 IWC 排放物）的幼鱼中，活性氧和乙酰胆碱酯酶活性存在差异。暴露于 10 倍稀释 IWC 排放物的幼鱼岩鱼的免疫和解毒系统也受到 10 倍稀释 IWC 排放物（锌：189.96 ± 47.76 μg/L，铜：1.97 ± 0.60 μg/L）的幼鱼的免疫和解毒系统受到显著影响。在所有暴露组中，与氧化应激相关的基因 Cu/Zn-SOD 、 GST 和 CAT 的表达在鱼类中均显著增加。具体来说，脑转录组学分析揭示了神经系统和稳态过程的紊乱。虽然致命毒性没有受到显着影响，但这些发现表明，亚致死浓度的 IWC 排放对幼鱼构成潜在危害，幼鱼在食物链中处于较高水平。 我们的酶和转录组学结果表明，以 Zn 为主的 IWC 排放暴露可能会导致海洋鱼类出现神经元和免疫毒性，为船体 IWC 排放管理提供相关见解，以保护沿海生态系统免受化学污染物的侵害。