Increased individual growth rate and community biomass of stream insects associated with salmon carcasses

AbstractWe showed that salmon carcass tissue can increase the growth rate of individual caddisflies as well as increase the local biomass of the aquatic insect community in 3 major stream habitat types. Sixteen insect taxa were found on salmon carcasses. The 7 dominant taxa in terms of biomass all had greater biomass in containers baited with salmon flesh in all habitats sampled; however, only 5 showed a significant salmon effect at the Bonferroni adjusted α of 0.007. The larval growth of Ecclisomyia conspersa was significantly greater on salmon muscle tissue than on conditioned leaves. Asynarchus pacificus grew significantly better with a combination of salmon and conditioned leaves than with either conditioned leaves or salmon muscle tissue alone. Our findings contribute to the understanding of the transfer of marine nutrients between generations of salmonids via aquatic insects, which are important prey items of juvenile salmonids.