TULSA, Okla. (AP) — The Oklahoma Department of Wildlife Conservation has investigated another fish kill below a dam after an angler reported he saw dozens of dead paddlefish at a lake outside Tulsa.

The Monday sighting at Fort Gibson Lake came after a fish kill last Friday below Tulsa's low-water Zink Dam, and another two weeks prior when water wasn't running at the Keystone Dam, the Tulsa World reported .

Angler pressure, unseasonably hot weather and lack of water flowing below the dam during such weather may have contributed to the deaths, according to biologists. But the scientists said they don't have enough information to determine if such reasons were the official cause.

"In really hot times, a few fish may be lost around in the stilling basin below the dam, we typically see this around July," said Preston Chasteen, spokesman for the Tulsa District Army Corps of Engineers.

Fisheries Biologist Jon West and Paddlefish Research Biologist Jason Schooley went Monday to investigate the recent fish kill, but the water was rising by the time they arrived.

"We counted 48 dead paddlefish in various stages of decomposition," West said. "We were able to note a few snagging scars on some of the fish but it was hard to determine what the problem was for sure. From the various levels of decay it appeared to be something that had been happening for a while."

The department is still grateful for on-site reports of such fish kills, he said.

"I'm glad they reported it and we were able to get there when we could," West said. "It's tough when we get a call three or four days later and all the evidence is gone."