Research Group in Community Nutrition and Oxidative Stress, University of Balearic Islands, 07122 Palma de Mallorca, Balearic Islands, Spain.
Department of Agricultura, Ramaderia, Pesca, Caça i Cooperació Municipal, Consell Insular d'Eivissa, 07800 Eivissa, Balearic Islands, Spain.
Sci Total Environ. 2024 Nov 15;951:175848. doi: 10.1016/j.scitotenv.2024.175848. Epub 2024 Aug 27.
Climate change associated with human activities alters marine ecosystems and causes imbalances and abrupt changes in sea conditions. Scarce freshwater resources for human consumption often prompt the construction of desalination plants, which discharge significant amounts of brine into the sea, potentially elevating salinity levels. Furthermore, global trade together with higher temperature and pollution can facilitate the spread of parasites. The aim of this study was to assess the potential effects of salinity, an abiotic stressor, and Scaphanocephalus sp. parasitic infection responsible for black spot disease, a biotic stressor, on Coris julis, a common fish in the Balearic Islands (Spain). Fish were sampled from an area affected by a desalination plant, one with a high rate of parasite infection and a control area, and biomarkers were analysed in the liver, gills and epithelial mucosa. Both salinity and the parasite induced increases in catalase (CAT) and glutathione s-transferase activities in the liver, while superoxide dismutase (SOD) did not show significant changes. The effects of salinity were evident to a greater extent in the gills with an increase in the activity of all enzymes, as well as in the production of reactive species. The effects of the parasite were mainly observed in the mucus with significant increases in CAT and SOD activities. Regarding immune response markers in the mucus, both stressors induced an increase in lysozyme and alkaline phosphatase activities, and in the case of the parasite, also an increase in immunoglobulins. Malondialdehyde, as an indicator of oxidative damage, remained unchanged. In conclusion, both abiotic and abiotic stress induce a stress situation in C. julis that responds by activating its antioxidant and immune defence mechanisms but does cause oxidative damage. The differential tissue response to different stressors highlights the value of analysing multiple tissues to detect early indicators of diverse impacts on marine fauna.
气候变化与人类活动有关，它改变了海洋生态系统，导致海洋环境失衡和突然变化。人类可用的淡水资源稀缺，这常常促使建造海水淡化厂，这些工厂将大量盐水排入大海，可能会提高盐度。此外，全球贸易以及更高的温度和污染会促进寄生虫的传播。本研究的目的是评估盐度（一种非生物胁迫因子）和导致黑斑点病（一种生物胁迫因子）的 Scaphanocephalus sp.寄生虫感染对巴利阿里群岛（西班牙）常见鱼类 Coris julis 的潜在影响。从一个受海水淡化厂影响的地区、一个寄生虫感染率高的地区和一个对照地区采集鱼类样本，并分析肝脏、鳃和上皮黏膜中的生物标志物。盐度和寄生虫都导致肝脏中的过氧化氢酶 (CAT) 和谷胱甘肽 S-转移酶 (GST) 活性增加，而超氧化物歧化酶 (SOD) 没有显示出显著变化。盐度的影响在鳃中更为明显，所有酶的活性增加，同时产生了更多的活性氧物质。寄生虫的影响主要在黏液中观察到，CAT 和 SOD 活性显著增加。关于黏液中的免疫反应标志物，两种胁迫因子都诱导了溶菌酶和碱性磷酸酶活性的增加，而在寄生虫的情况下，还诱导了免疫球蛋白的增加。丙二醛作为氧化损伤的指标保持不变。总之，非生物和生物胁迫都会在 C. julis 中引起应激反应，通过激活其抗氧化和免疫防御机制来应对，但不会引起氧化损伤。不同组织对不同胁迫因子的不同反应突出了分析多个组织以检测对海洋动物群的不同影响的早期指标的价值。
