A study published in the journal Science reveals the decreasing size of Atlantic salmon in Finland's River Teno might be attributed to the indirect effects of aquaculture, specifically the commercial fishery of capelin, a key food source for wild salmon. The research, which analyzed genetic data and environmental factors over four decades, also uncovered a direct impact of salmon fishing in the river, particularly with the use of certain nets capturing smaller fish. The findings highlight the complex interplay between human activities and the evolution of fish populations, underscoring the need to consider these factors in salmon management and the efforts to reduce the impact of aquaculture on wild fish.