Pelicans have flown in from the Gulf Coast to feed on fish killed by a late-season algae bloom.
Officials say more than 100,000 fish have died in two golden alga-infested Texas lakes, kills so large that pelicans are apparently flying hundreds of miles from the Gulf Coast to feed.
The Texas Parks and Wildlife Department estimates that at least 50,000 fish have died at Possum Kingdom lake in North Texas. Officials said at least another 68,900 are dead about 90 miles to the southeast in Lake Whitney. Possum Kingdom lake and Lake Whitney are part of the Brazos River system
"Over the last 10 days, there were lots of pelicans, lots of shore birds and buzzards, eating the dead fish," said Brady Dempsey, of the U.S. Army Corps of Engineers, Fort Worth District.
Dempsey said he hated that so many fish had died.
"(It) just makes it harder for people who make their living off fishing guides and lodges and that sort of stuff," Dempsey said. "And then people that come out to the lake bring kids to fish and that sort of stuff. (It's) a lot harder for them to catch fish when that many of them have died."
Golden algae is not native to the region. It was likely introduced by someone emptying boat wells filled with water from an infected lake into Possum Kingdom Lake and Lake Whitney, a Texas Parks and Wildlife Department biologist said last week.
"The algae itself is very abrasive, and it nicks their gills," Dempsey said. "They basically bled to death and can't take oxygen from the water, and so they basically bled and suffocate."
The late-season golden algae bloom peaked in April instead of the more typical January. In January, it isn't as noticeable because the cold weather keeps the dead and dying fish from floating.
But Dempsey said the fish kill is coming to an end because of rising temperatures and higher lake levels.
"The rains that we had upstream and the water that was flushed down through Possum Kingdom lake and Granbury Lake has raised the lake level, and it seems to have slowed or ended the kill," he said.
He said the pelicans that flew inland have mostly left Possum Kingdom lake.
NBC DFW's Shane Allen contributed to this report.