Beginning in 1877, Japan imported California rainbow trout for food and sport fishing; escaped fish later competed with native salmonids and disrupted their spawning grounds

In 1877, Japan imported rainbow trout from California for culinary and recreational purposes. However, these fish escaped their aquaculture environments and began to disrupt local ecosystems by competing with indigenous species. They overlap critical feeding habitats and can decimate the eggs of native fish. Additionally, rainbow trout frequently engage in territorial disputes, outcompeting native species. Current management strategies focus on mitigating their spread without fully eliminating these sought-after fish.