Scientists cull millions of invasive sea lampreys yearly to protect Great Lakes fish

Sea lampreys, an invasive species nicknamed 'vampire fish', have severely threatened native fish populations in the Great Lakes after entering via canals. These predatory fish consume large quantities of fish each year, causing significant ecological damage. Since 1957, a chemical compound called TFM has been the primary tool used to eliminate lamprey larvae from the region. However, when management efforts are paused or disrupted, lamprey populations have rebounded sharply. As a result, scientists continue to cull around 9 million sea lampreys annually to keep their numbers under control.