On the underappreciated role of scavengers in freshwater ecosystems.

Abstract

The role of scavengers is well understood in terrestrial and marine systems but less so in freshwater ecosystems. We synthesized existing knowledge of scavenger ecology in freshwater, particularly within the context of the Anthropocene, including the patchy distribution of carrion, consumer responses, competition, and transfer of energy, nutrients, and diseases. We also explored ecosystem services provided by freshwater scavengers, such as direct material benefits and improvements in water quality. In addition, we examined how human activities-such as climate change, disturbance, exploitation, and fragmentation-are affecting scavenger behavior and abundance. To mitigate these anthropogenic impacts, we identified management options for environmental practitioners and decision-makers, emphasizing the importance of integrating freshwater scavenger roles into management plans and providing adequate policy protections. Finally, we highlighted key knowledge gaps, particularly regarding how changes in scavenger populations and their food sources may alter ecosystem structure and function.