School of Marine Sciences, Sun Yat-sen University, Zhuhai 519082, China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519000, China.
School of Marine Sciences, Sun Yat-sen University, Zhuhai 519082, China; Frontiers Science Center for Deep Ocean Multispheres and Earth System, and Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519000, China.
Water Res. 2022 Jun 30;218:118520. doi: 10.1016/j.watres.2022.118520. Epub 2022 Apr 29.
Coastal wetland reclamation contributed to development of aquaculture industry, and the residual bait accumulation in aquaculture processes could influence biogeochemical elements cycling, which threaten ecological functions and services in aquaculture and adjacent ecosystems. However, systematic studies for changes in sediment microbial community structure and greenhouse gasses (GHGs) production, as well as environmental parameters following bait input at time scale are still rare. A 90-day incubation experiment was conducted using sediment collected from coastal wetland in Qi'ao Island in southern China, followed by the observations of temporal variations of physicochemical properties, sediment microbial community, and GHGs production in response to different amounts of bait input (0, 20, and 40 mg bait g wet sediment). The results showed that dissolved oxygen of overlying water was profoundly decreased owing to bait input, while dissolved organic carbon of overlying water and several sediment properties (e.g., organic matter, sulfide, and ammonium) varied in reverse patterns. Meanwhile, bait input led to significant loss of microbial community richness and diversity, and strongly altered microbial compositions from aerobic, slow-growing, and oligotrophic (Actinobacteriota, Chloroflexi, and Acidobacteriota) to anaerobic, fast-growing, and copiotrophic (Firmicutes and Bacteroidota). Moreover, both GHGs production and global warming potential were significantly enhanced by bait input, implying that aquaculture ecosystem is an important hotspot for global GHGs emission. Overall, bait input triggered quick responses of physicochemical properties, sediment microbial community, and GHGs production, followed by long-term resilience of the ecosystem. This study could provide new insight into temporal interactive effects of bait input on physicochemical properties, microbial community, and GHGs production, which can enhance the understanding of the temporal dynamics and ecological impacts of coastal aquaculture activities and emphasize the necessity of sustainable assessment and management in aquaculture ecosystems.
沿海湿地开垦促进了水产养殖业的发展，而水产养殖过程中的剩余诱饵积累会影响生物地球化学元素的循环，从而威胁水产养殖和相邻生态系统的生态功能和服务。然而，关于诱饵输入后沉积物微生物群落结构和温室气体（GHGs）产生的系统变化以及环境参数的时间尺度的研究仍然很少。在中国南部淇澳岛沿海湿地采集沉积物进行了为期 90 天的孵化实验，随后观察了不同诱饵输入量（0、20 和 40mg 诱饵 g 湿沉积物）下，对水层和沉积物理化性质、微生物群落和 GHGs 产生的时间变化。结果表明，由于诱饵输入，上覆水的溶解氧明显降低，而上覆水的溶解有机碳和几种沉积物特性（如有机质、硫化物和铵）则呈相反的变化趋势。同时，诱饵输入导致微生物群落丰富度和多样性显著丧失，并强烈改变了微生物组成，从好氧、生长缓慢、贫营养型（放线菌门、绿弯菌门和酸杆菌门）转变为厌氧、生长迅速、富营养型（厚壁菌门和拟杆菌门）。此外，诱饵输入显著增加了 GHGs 的产生和全球增温潜势，这意味着水产养殖生态系统是全球 GHGs 排放的一个重要热点。总体而言，诱饵输入触发了理化性质、沉积物微生物群落和 GHGs 产生的快速响应，随后是生态系统的长期恢复力。本研究可为诱饵输入对理化性质、微生物群落和 GHGs 产生的时间相互作用提供新的见解，从而增强对沿海水产养殖活动的时间动态和生态影响的理解，并强调水产养殖生态系统可持续评估和管理的必要性。
