Department of Ecological Sciences and Engineering, Chongqing University, Chongqing, 400045, PR China.
Guangdong Provincial Key Laboratory of Water Quality Improvement and Ecological Restoration for Watersheds, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou, 510006, China.
J Environ Manage. 2024 Feb 27;353:120155. doi: 10.1016/j.jenvman.2024.120155. Epub 2024 Feb 2.
Dimethylsulfide (DMS) is a major organic sulfide in aquatic ecosystems and an infochemical that is considered as a key predictor of changes in energy and material fluxes and stocks. It is largely unknown how DMS changes and affects the food webs and material cycles in eutrophicated freshwater. In this study, field monitoring and literature surveys were conducted to analyze the effects of eutrophication on DMS concentrations. Daphnia-zebrafish microcosms were then used to investigate the effects of DMS concentrations on carbon transfer. The results demonstrated that the concentration of DMS was increased by eutrophication related indicators (chlorophyll and phosphorus). Eutrophication driven DMS altered carbon transfer in the freshwater food chain. Low concentrations (0.1-1 nM) of DMS promoted the predation of daphnia by zebrafish compared to the 0.01 nM DMS, which further stimulated the total carbon transfer from daphnia to zebrafish and altered the dissolved organic carbon (DOC) distribution in water. High concentrations (10-100 nM) of DMS did not alter zebrafish predation on daphnia and carbon transfer. DOC excreted by zebrafish altered carbon emission potential, and DMS in water showed a unimodal relationship with the carbon emission potential, peaking at 0.40 nM DMS. Keeping the DMS in water at 1.82 nM may maintain a lower carbon emission potential. These results improved the understanding of the effects of eutrophication on DMS, demonstrated the ecological role of DMS on freshwater fish and the carbon cycle, estimated the effects of DMS on the carbon emission potential of fish, and offered new insights into the management of eutrophication.
二甲基硫（DMS）是水生生态系统中的一种主要有机硫化物，也是一种信息素，被认为是能量和物质通量和存量变化的关键预测因子。目前还不清楚 DMS 如何变化以及如何影响富营养化淡水的食物网和物质循环。本研究通过野外监测和文献调查分析了富营养化对 DMS 浓度的影响。然后使用大型蚤-斑马鱼微宇宙来研究 DMS 浓度对碳转移的影响。结果表明，DMS 的浓度随着富营养化相关指标（叶绿素和磷）的增加而增加。富营养化驱动的 DMS 改变了淡水食物链中的碳转移。与 0.01 nM DMS 相比，低浓度（0.1-1 nM）的 DMS 促进了斑马鱼对大型蚤的捕食，这进一步刺激了从大型蚤到斑马鱼的总碳转移，并改变了水中溶解有机碳（DOC）的分布。高浓度（10-100 nM）的 DMS 不会改变斑马鱼对大型蚤的捕食和碳转移。斑马鱼排泄的 DOC 改变了碳排放潜力，水中的 DMS 与碳排放潜力呈单峰关系，在 0.40 nM DMS 时达到峰值。将水中的 DMS 保持在 1.82 nM 可能会降低碳排放潜力。这些结果提高了对富营养化对 DMS 影响的认识，展示了 DMS 对淡水鱼类和碳循环的生态作用，估计了 DMS 对鱼类碳排放潜力的影响，并为富营养化的管理提供了新的见解。
