Coastal ecosystems are vital for maintaining biodiversity and providing essential ecosystem services; however, they are increasingly threatened by pollution and eutrophication resulting from human activities, particularly wastewater discharge. Nutrient-rich effluents from wastewater treatment plants (WWTPs) introduce excessive inorganic nutrients and pollutants, which disrupt microbial community structures and functions. Since microbial ecosystems play crucial roles in biogeochemical cycles, understanding their responses to pollution is essential for accurately predicting ecological outcomes. Our research specifically investigates the impact of these anthropogenic disturbances on microbial communities within polluted coastal sediments. Our initial study examined sediment bacterial communities in Hangzhou Bay, China, exposed to varying levels of WWTP effluent discharge. This revealed a significant decrease in microbial diversity correlating with increased pollution levels. As environmental selection intensified under these conditions, we observed diminished species migration, a reduction in the microbial rare biosphere, greater phylogenetic clustering, and simpler community interactions. Building on our findings in Hangzhou Bay, we subsequently conducted a global-scale integrative analysis to explore the broader implications of nutrient enrichment on microbial community dynamics. This comprehensive analysis culminated in formulating the "hunger games" hypothesis, which elucidates universal principles that govern the regulation of microbial diversity and ecological interactions in response to nutrient inputs across various environments. Overall, our findings emphasize the significant impacts of WWTP effluents on coastal microbial communities and highlight the potential consequences of biodiversity loss on ecosystem functioning. The "hunger games" hypothesis serves as a valuable framework for understanding how nutrient enrichment influences microbial communities worldwide, ultimately guiding future research in microbial ecology and ecosystem management.

microbial ecology,nutrient enrichment,coastal ecosystem,anthropogenic disturbances,biodiversity loss