400,000 chinook salmon smolts died because a fish carcass clogged an intake pipe.
The Oregon Department of Fish and Wildlife (ODFW) released a statement on Monday notifying the public that 400,000 chinook salmon pre-smolts had perished at the state’s Rock Creek Hatchery due to a clogged intake pipe at the hatchery.
The pipe became clogged when a fish carcass lodged in it, effectively slowing the flow of fresh water to the smolts.
While the diminished water flow was not enough to trigger an alarm, the lack of sufficient fresh, oxygenated water, and increasing temperature in the holding tanks, was enough to kill hundreds of thousands of young fish.
An employee noticed that something was wrong and sounded the alarm but it only took one hour after the pipe became clogged before the damage was done and the salmon smolts were lost.
Hatchery manager, Dan Meyer, said in the press release; “We have a new intake and a new emergency valve we can open. If power to the screens is out, water to the hatchery is severed, and the emergency valve will get water to fish. It was opened for short time during a power outage a few months ago when the emergency generator failed, and we think the carcass may have gotten into the water line then.”
The smolts were scheduled to be released next year into the North Umpqua River. From there they would migrate to the ocean before returning to the Umpqua as three- and five-year-olds. Anglers will feel the loss most prominently in 2018 and 2019.
Normally 4,000 to 6,000 catchable salmon return to the Umpqua and North Umpqua Rivers each year, where they are targeted by anglers. Obviously those numbers will be significantly lower in a few years due to this loss.
The ODFW indicated that hatchery staff are seeking to avoid any possible future mishaps of this nature by re-evaluating protocols and the current alarm system.