Fisheries College, Guangdong Ocean University, Zhanjiang, China.
Fisheries College, Guangdong Ocean University, Zhanjiang, China; Pearl Oyster Research Institute, Guangdong Ocean University, Zhanjiang, China; Guangdong Provincial Science and Technology Innovation Center of Marine Invertebrates, Guangdong Ocean University, Zhanjiang, China; Guangdong Provincial Key Laboratory of Aquatic Animal Disease Control and Healthy Culture, Guangdong Ocean University, Zhanjiang, China.
Mar Environ Res. 2024 Nov;202:106716. doi: 10.1016/j.marenvres.2024.106716. Epub 2024 Aug 28.
Marine heatwaves (MHWs) are increasing in frequency and intensity, threatening marine organisms and ecosystems they support. Yet, little is known about impacts of intensifying MHWs on ecologically and economically important bivalves cultured in the South China Sea. Here, we compared survival and physiological responses of five bivalve species, Pinctada fucata, Crassostrea angulata, Perna viridis, Argopecten irradians and Paphia undulata, to two consecutive MHWs events (3 days of thermal exposure to + 4 °C or + 8 °C, following 3 days of recovery under ambient conditions). While P. fucata, P. viridis, and P. undulata are native to the South China Sea region, C. angulata and A. irradians are not. Individuals of P. fucata, C. angulata and P. viridis had higher stress tolerance to MHWs than A. irradians and P. undulata, the latter already experiencing 100% mortality under +8 °C conditions during the first event. With increasing intensity of MHWs, standard metabolic rates of all five species increased significantly, in line with significant depressions of function-related energy-metabolizing enzymes (CMA, NKA, and T-ATP). Likewise, activities of antioxidant enzymes (SOD, CAT, and MDA) and shell mineralization-related enzymes (AKP and ACP) responded significantly to MHWs, despite species-specific performances observed. These findings demonstrate that some bivalve species can likely fail to accommodate intensifying MHWs events in the South China Sea, but some may persist. If this is the case, then one would expect substantial loss of fitness in bivalve aquaculture in the South China Sea under intensifying MHWs conditions.
海洋热浪（MHWs）的发生频率和强度正在增加，对它们所支持的海洋生物和生态系统构成威胁。然而，对于南海养殖的具有生态和经济重要性的双壳贝类在不断加剧的海洋热浪事件中的影响，人们知之甚少。在这里，我们比较了五种双壳贝类的存活和生理反应，包括珍珠贝（Pinctada fucata）、长牡蛎（Crassostrea angulata）、绿贻贝（Perna viridis）、栉孔扇贝（Argopecten irradians）和波纹巴非蛤（Paphia undulata），它们分别对两次连续的海洋热浪事件（在 3 天的热暴露于+4°C 或+8°C 后，在环境条件下恢复 3 天）的反应。尽管 P. fucata、P. viridis 和 P. undulata 原产于南海地区，但 C. angulata 和 A. irradians 并非如此。在第一次事件中，P. fucata、C. angulata 和 P. viridis 的个体对海洋热浪的耐受能力高于 A. irradians 和 P. undulata，后者在+8°C 条件下已经经历了 100%的死亡率。随着海洋热浪强度的增加，所有五种物种的标准代谢率都显著增加，与功能相关的能量代谢酶（CMA、NKA 和 T-ATP）的显著抑制一致。同样，抗氧化酶（SOD、CAT 和 MDA）和壳矿化相关酶（AKP 和 ACP）的活性也对海洋热浪有显著反应，尽管观察到了物种特异性的表现。这些发现表明，一些双壳贝类可能无法适应南海不断加剧的海洋热浪事件，但也有一些可能会持续存在。如果是这样，那么在南海不断加剧的海洋热浪条件下，双壳贝类养殖的适应性可能会大大降低。
