How Agriculture Is Reshaping—and Destabilizing—Stream Food Webs

An image of a tractor farming agricultural land.

A new study co-authored by the Centre for Ecosystem Management’s Dr. Kevin McCann reveals that agricultural land use—especially nutrient runoff and the loss of streamside vegetation—is reshaping how energy flows through stream food webs. Sampling across seasons, the research shows that in heavily farmed areas, stream animals rely less on land-based food sources, fish communities are dominated by smaller individuals, and food webs become simplified and fast-cycling. These changes point to reduced stability, underscoring the importance of maintaining riparian zones and managing nutrient inputs to support resilient freshwater ecosystems.

Marie K. Gutgesell, Matthew M. Guzzo, and Kevin S. McCann. 2025. Agricultural land-use change seasonally rewires stream food webs: a case study from headwater streams in the Lake Erie watershed. FACETS. 10: 1-13.

Helen Vanosfood webs, agriculture, freshwater, ecosystems, fish