Guangdong Provincial Key Laboratory of Fishery Ecology and Environment, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China; CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China.
CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China.
Ecotoxicol Environ Saf. 2022 Jun 15;238:113606. doi: 10.1016/j.ecoenv.2022.113606. Epub 2022 May 6.
An outbreak of a macrozooplankton Creseis acicula occurred in the summer of 2020 nearby the Daya Bay Nuclear Power Plant located on the coast of the Daya Bay in the South China Sea. The outbreaks of C. acicula often threaten human health, the marine environment, and other human activities including the safe operation of coastal nuclear power plants. Seawater temperature has been suggested as an important factor influencing such outbreaks. However, the underlying mechanisms through which temperature influences C. acicula remains unknown. Here, we studied the effects of temperature on the ingestion and assimilation of algal food by feeding radiocarbon-labeled algae Chlorella sp. at simulated field temperatures (19-31 °C) to C. acicula collected during the outbreak in the Daya Bay. We also quantified the allocation of the food carbon to dissolved organic carbon (DOC), CO, and fecal pellets. The results showed that the zooplankton during the same feeding time ingested doubled or tripled algal food at higher temperatures, and it produced and released significantly more DOC, CO, and fecal pellets with more ingested food carbon. Meanwhile, the assimilation efficiency for the ingested food carbon slightly increased from 48% to 54% with rising temperature. As a result, higher assimilation rates indicating faster growth of C. acicula were observed at higher temperatures. In addition, the high activation energy of 0.908 eV indicated that the assimilation rate was very sensitive to temperature rising. Our results show that relatively rising temperature can enhance C. acicula's ingestion and assimilation rates for algal food, benefit its growth and metabolism, and contribute to its outbreak. This study provides a mechanistic interpretation for the relationship between rising temperature and the outbreaks of C. acicula and suggests that such outbreaks may occur more frequently and widely in the warming ocean.
2020 年夏，在中国南海大亚湾附近的大亚湾核电站沿海地区，发生了一次大型浮游动物箭虫的暴发事件。箭虫的暴发常常威胁着人类健康、海洋环境和其他人类活动，包括沿海核电站的安全运行。海水温度被认为是影响此类暴发的一个重要因素。然而，温度影响箭虫的潜在机制尚不清楚。在这里，我们研究了温度对在大亚湾暴发期间采集的箭虫在模拟野外温度（19-31°C）下摄食和同化放射性碳标记藻类小球藻的影响。我们还量化了食物碳向溶解有机碳（DOC）、CO 和粪便颗粒的分配。结果表明，在同一摄食时间内，在较高温度下，浮游动物摄入的藻类食物增加了一倍或两倍，并且产生和释放的溶解有机碳（DOC）、CO 和粪便颗粒明显更多，同时，随着温度的升高，对摄入食物碳的同化效率略有从 48%增加到 54%。因此，在较高温度下，观察到箭虫的同化率更高，表明其生长更快。此外，较高的 0.908 eV 活化能表明同化率对温度升高非常敏感。我们的结果表明，相对升高的温度可以增强箭虫对藻类食物的摄食和同化率，有利于其生长和代谢，并有助于其暴发。本研究为温度升高与箭虫暴发之间的关系提供了一种机制解释，并表明在变暖的海洋中，此类暴发可能更频繁、更广泛地发生。
