ANTHONY LAKE — A state fish biologist is trying to figure out what killed about 200 of the 2,000 hatchery rainbow trout released in Anthony Lake in late July.

The incident was unfortunate because the alpine lake, at an elevation of 7,100 feet in the Elkhorn Mountains northwest of Baker City, “is one of those places where people really enjoy going to fish during the hot summer months,” said Joe Lemanski, district fish biologist at the Oregon Department of Fish and Wildlife’s La Grande office.

The trout are considered “trophy” fish, as they average about a pound and a half, he said.

Lemanski sent several fish carcasses to ODFW’s fish pathology lab for examination. He said he hopes to have results within a couple weeks.

There are several potential causes, he said, any of which alone, or in combination, could have killed the trout, which were released in the 22-acre lake on July 26.

Possibilities include accidental injuries during loading, transporting, and releasing fish, mechanical failure of instrumentation on the transport trucks, shock from the difference in water temperature between the truck and the lake, and possible infection or disease exacerbated by any one of these factors.

“We’re trying to piece it together,” Lemanski said.

He said it might not be possible to pinpoint the cause of the fish deaths.

Lemanski said there is no evidence, however, that the problem is not solely with the lake conditions, or any mechanical failures or issues during transport — the dieoff seems to have been limited to some of the fish released July 26, and is likely a combination of a few factors.

He said ODFW didn’t receive any reports of dead fish following a release of 2,000 trophy rainbow trout in Anthony Lake, from the same hatchery, three weeks earlier, on July 5.

Nor were there any reports of dead fish at nearby Grande Ronde Lake, where rainbow trout were also released during July.

Anglers have continued to catch fish in Anthony Lake, Lemanski said, and he said the lake remains a good place to hook rainbow or brook trout.

Lemanski said ODFW began to get reports from anglers soon after the July 26 release, including one report from a Forest Service employee who took photos of dead fish.

The dead trout were concentrated near the boat ramp at the southeast corner of the lake — which is where the hatchery truck disgorges its load of rainbow trout.

Lemanski said it doesn’t appear that a large number of fish were dead before they were released, however, since there were no reports of dead fish floating near the boat ramp during or immediately after the release.

He suspects most of the fish died within a day or less, based on the timing of the reports.

Lemanski encouraged anglers and others who see more than a few dead fish in one area to document the scene with photographs and a tally of the fish, then report the incident to ODFW by calling 541-963-2138.