F&G reports loss of young chinook at McCall Hatchery

Idaho Fish and Game reported a mortality event that resulted in about 33,000 young Chinook dying at the McCall Fish Hatchery in late July. The fish died from a lack of adequate oxygen supply in the rearing unit where they were being held.

The hatchery is rearing about 1.5 million young Chinook that will be released in the spring to migrate to the ocean. The 33,000 fish that died were among about 139,000 young Chinook that are being raised at the hatchery on behalf of the Nez Perce Tribe, so it will reduce that future release into Johnson Creek by about 24 percent to about 106,000 young fish.

The McCall Hatchery supplies Chinook to the South Fork of the Salmon River and nearby Johnson Creek. The Johnson Creek program is focused on restoring the wild summer Chinook population in Johnson Creek using hatchery-reared fish to increase abundance.

The incident will not affect future Chinook fisheries on the South Fork of the Salmon, however, Fish and Game regrets the loss of these important fish, and they have been in communications with Nez Perce Tribe Fisheries Department.

"We recognize that Fish and Game hatchery staff work hard every day, year round and have a huge amount of time and effort invested in these fish," said Becky Johnson, Nez Perce Tribe Production Division Director. "It's a huge loss, but we understand it wasn't intentional, and that it's unfortunate for everyone."

She added the Tribe recognizes there's an element of risk involved in raising young Chinook in hatcheries, but "that risk is worth the benefit because Snake River spring/summer Chinook are at very low levels and supplemental hatchery Chinook are critical to boost these runs."

The young Chinook had been moved to a rearing unit after being tagged in a marking trailer designed for tagging and marking fish. Water was being pumped into the rearing unit from the marking trailer and the rearing unit's internal plumbing. When the marking operation was completed, the portion of the water fed into the rearing unit from the trailer was shut off, but additional water was not re-established. During the night, roughly half the fish in the rearing unit died from a lack of adequate oxygen supply.

"We deeply regret that this accident occurred, and we appreciate the Tribe's understanding. We are committed to ensuring it will not be repeated in the future," said Beau Gunter, Fish and Game's Fish Production Program Manager.