Shoreline bank construction modifies benthic–pelagic coupling of food webs

Management of the food web is important in maintaining ecosystem functions; however, the studies to assess anthropogenic impact on food web structures are very limited. Recently, shoreline development is considered to impact the littoral zone of lakes through loss of littoral habitats. Shoreline engineering would consequently modify the food web structure and coupling between benthic and pelagic habitats. Thus, we investigated whether lakeshore modification would change benthic–pelagic coupling by largemouth bass in 15 ponds, which differed in the proportion of concrete bank modification. We performed isotope mixing models to estimate benthic contribution to the fish species and tested the relationships with environmental factors including proportion of bank modification by general linear models. These results showed that the benthic contribution to largemouth bass was strongly related to the proportion of anthropogenic shoreline modification, while for bluegill sunfish, the benthic contribution was not changed with anthropogenic shoreline modification. Therefore, anthropogenic modification of shoreline strongly modified the food webs in ponds through the littoral habitat modification. The results suggested that we should pay attention to the anthropogenic impact on food web structures to maintain ecosystems.