Do you have links to those stories?
Just go to google.com
and choose advanced search
enter: fish kill
into the box titled “this exact wording or phrase”
expand the “Date, usage rights, numeric range, and more”
and at the “date” selection, choose “past month”
Hit the “advanced search” button
You should get about 139,000 hits.
My conclusion after looking through about 50 pages of links was that there is an unreported nation-wide fish kill in progress;
blamed on a variety of causes:
heat, algae, red-tide, low O2 levels, foam, oil spills, toxic run-off, intentional poisoning, natural selection and in many cases unexplained or under investigation.