9781888569445-ch7

Nutrients in Salmonid Ecosystems: Sustaining Production and Biodiversity

Aquatic Animal Colonization of Chum Salmon Carcasses in Hokkaido, Northern Japan

Miyuki Nakajima and Tomiko Ito

doi: https://doi.org/10.47886/9781888569445.ch7

Abstract.—We observed that the aquatic animals, especially macroinvertebrates, colonized chum salmon Oncorhynchus keta carcasses in six rivers of five coastal districts in Hokkaido, northern Japan, 1997–2000. Fifty-six taxa of aquatic macroinvertebrates were found with the carcasses. Taxa and number of the macroinvertebrates were different among rivers and districts. Three taxa, Gammaridea (Amphipoda), Hydatophylax spp. (Trichoptera: Limnephilidae), and Chironomidae (Diptera), were widely and abundantly found. Hydatophylax larvae were more abundant on the carcasses, in comparison with the streambed, in some sites. The maximum number of macroinvertebrates colonizing a carcass was observed near an estuary site of the Shiretoko District, 747 on average of Eogammarus spp. (Gammaridea).