Anadromous fishes such as salmonids link marine and terrestrial ecosystems in
coastal watersheds of western North America. We examine here the extent of isotopic enrichment
of salmon-derived nutrients in soil, vegetation, and terrestrial insects among six
watersheds from coastal British Columbia that differ in the density of salmon spawning
abundance. Results demonstrate a direct relationship between the salmon spawning density
and 15N enrichment in humus soil, in riparian vegetation (Tsuga heterophylla, Vaccinium
parvifolium, Rubus spectabilis), and in riparian insects including herbivorous and carnivorous
Carabidae (Pterostichus, Scaphinotus, Zacotus). The results suggest broad cycling of
salmon-derived nutrients into multiple trophic levels of terrestrial ecosystems. We also
describe for the first time the detection of salmon-derived nitrogen in wood samples extracted
from old-growth riparian. This result suggests new opportunities for assessing relative
nutrient transfer and salmon abundance in past centuries.