Tuesday March 10, 2026
Phys —
More than 40% of extant large freshwater animals (megafauna), including carp, salmonids, crocodilians, turtles, beavers, and hippopotamuses, have been deliberately introduced outside their natural range, often for economic gain. While these alien species can provide substantial benefits to certain groups in the introduced regions, they also pose profound and often underestimated risks to native biodiversity and local people, according to a new study published in One Earth, led by researchers at the Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB) and the Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences.
Nile perch in Lake Victoria is a prominent example showing the complex ecological and socioeconomic impacts posed by alien freshwater megafauna. The introduction was intended to enhance fisheries, but it has caused serious consequences: stocks of native fish species declined, local fishers lost their livelihoods, and chronic malnutrition among children and mothers increased in the surrounding communities.