Invasive carp make up 90% of Mississippi River fish die-off

Hundreds of dead fish have washed up along the Mississippi River in Missouri and Illinois, with wildlife officials saying the die-off is mostly of invasive carp. The deaths, concentrated at Riverside Landing Park in St Charles County, Missouri, are linked to warm temperatures, low water levels, and reduced oxygen.

Dan Zarlenga of the Missouri Department of Conservation said about 90 per cent of the dead fish were silver and bighead carp, both invasive species. He said native fish are better adapted to summer conditions and the event could benefit the ecosystem by reducing competition for resources.

Dead carp have also been reported near Melvin Price Lock and Dam in Illinois and along other river sections. Officials expect birds and wildlife to feed on the carcasses and will continue monitoring the river's fish populations.