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 examines how farming practices influence the seasonal balance of land- and water-based food sources in stream food webs throughout the Lake Erie watershed.

The study reveals that agricultural land use—especially nutrient runoff and the loss of streamside vegetation—is reshaping how energy flows through stream food webs.

In heavily farmed areas, stream animals begin to 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.

To learn more, check out the full news release here.

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