Fish mortality observed in lower Madison River
May 26, 2021
Fisheries biologists with Montana Fish, Wildlife & Parks are monitoring an area of the Madison River where a number of dead fish have been observed.
A cause of the mortalities has not yet been determined. Biologists have collected many samples from dead and dying fish and submitted them for testing.
The dead fish were first reported to FWP on May 18 by anglers floating in Beartrap Canyon. FWP staff immediately went to the area and found several dead mountain whitefish. Since then, FWP staff have floated Beartrap Canyon and walked the banks of the river downstream of the Warm Springs Boat Launch each day to gather information on the mortality.
By 3 p.m. on May 20, FWP staff had observed dead fish over 10 miles from just upstream of Ennis Dam to the Warm Springs Boat Launch on the Madison River. These include about 814 whitefish, 11 brown trout, 6 rainbow trout, and three suckers so far.
"We are working hard monitoring the situation and investigating the causes of the mortalities," said FWP Fisheries Division Administrator Eileen Ryce. "We appreciate the reports from the public on the dead fish they're seeing, and that's been an important part of the monitoring we've done."
FWP staff will continue to monitor conditions on the Madison River. More information will be provided as it becomes available. If anglers see dead or dying fish, they can call the FWP Bozeman office at 577-7900.
Anglers can help reduce stress for fish by following these practices when catching and releasing fish:
• Land the fish quickly.
• Wet your hands before handling the fish.
• Keep the fish in water as much as possible.
• Remove the hook gently. Using artificial lures with single and barbless hooks can make hook removal faster and easier. If the fish is hooked deeply, you may have to snip the line at the fish's mouth or consider keeping it if regulations allow.
• Let the fish recover before releasing it.