Hatch house woes
TRAIL — Dave Pease opens a tray of spring chinook salmon eggs just now hatching at Cole Rivers Hatchery and gives them a little cleaning that could save their lives or kill them.
Guided by a red-light head lamp so as not to stress the tiny chinook still emerging from the eggs, Pease runs a small paint roller over the top of the tray to cleanse it of a brown algae hatchery workers can’t seen purge from its water supply.
Called diatoms, the brown algae last year killed more than 1 million spring chinook fry and caused the hatchery to miss its chinook release target to the Rogue River by more than one-quarter.
Back-to-back losses would be a double-whammy to the Rogue’s fishery, because only hatchery chinook are legal for Rogue anglers to keep during the bulk of the season. So four daily cleanings like this are anything but routine.
“It’s a Catch-22,” says Pease, the hatchery’s manager. “You have to do it. You can hurt them in the process, but we have to take our chances.
“It’s unnerving,” he says. “The whole staff is on pins and needles.”
The hatchery is in the midst of its first real test of a jerry-rigged water system bypass meant as a short-term solution for keeping clean water flowing over 2.2 million chinook eggs at the 47-year-old facility while a longterm solution is sought.
The Oregon Department of Fish and Wildlife, which operates the hatchery for the U.S. Army Corps of Engineers, spent about $15,000 for a system of PVC pipes and fittings to bypass old metal pipes and other parts of the water system discovered rife with diatoms during last year’s die-off.
Now hatchery technicians are checking and gently scrubbing diatoms from fish trays, and they will continue to do so until these tiny fish get moved out of the hatch house to outdoor ponds in January.
“It’s a very fragile time in a fish’s life,” Pease says. “It doesn’t take much to hurt them.”
And now they are perhaps at their most vulnerable to death by diatoms.
As the fish absorb their egg sacs and turn into fry, they release nutrients on which diatoms thrive, Pease says.
“This is right at the start of it, and it’s a difficult position for us to be in,” Pease says.
The diatoms weren’t always present at Cole Rivers Hatchery, but over the years they have showed up in the water supply — not at real bad levels, until last year’s massive outbreak.
Even with the new bypass system in place, the diatoms are building up in the egg trays daily — not to the lethal levels of last year, but enough to keep Pease guessing.
“It makes me think that what we’re doing is helping, but it’s not cured the problem.”
The Army Corps of Engineers is in the early stages of setting up teams to look at options for fixing the water system and choosing the best alternative, said Bob Wertheimer, who oversees the Corps contract with ODFW for Cole Rivers.
The Corps owns the facility and operates it to grow chinook and steelhead to make up for those wild fish blocked from historic natural spawning areas by the placement of Lost Creek and Applegate dams.
Wertheimer says he knows the bypass system is not a cure-all, and that the hatchery, in operation since 1972, likely needs a new system for delivering water from the Rogue and Lost Creek Lake.
“I suspect it will be a complete redesign,” says Wertheimer, who has no timeline for the work. Water woes at Cole Rivers comes as Curry and Josephine counties, as well as sport-fishing groups, have questioned why the hatchery fails to generate enough adult returns to the Rogue to support fisheries promised from hatchery fish in return for wild fish lost to dam construction.
Lost Creek dam blocked about one-third of wild spring chinook spawning habitat, and one group claims that spiraling returns have cost close to $300 million in lost economic value to Jackson, Josephine and Curry counties, where spring chinook angling is a big draw for locals and tourists.
Wertheimer says the Corps will keep Josephine and Curry counties, which have met with the Corps over concerns on hatchery operations, in the loop on future steps to fix the hatchery’s water system.
Reach Mail Tribune reporter Mark Freeman at 541-776-4470 or firstname.lastname@example.org. Follow him on Twitter at www.twitter.com/MTwriterFreeman.