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Hatcheries take steps to cool Lewis County rivers for fish

Below normal flow levels and warm water in the region’s rivers are making this summer a challenge for fish.

Officials with the state Department of Fish and Wildlife have restricted fishing on parts of some rivers in the state to protect fish in those systems. Similar restrictions could happen in South Sound and Lewis County later this month, said Steve Thiesfeld, WDFW fish program manager for Region 6.

“We’re not seeing mortality right now that makes me think we’ve got some major issues,” Thiesfeld said. “But I would suspect that by the end of July, certainly, I suspect you’re going to start to see some emergency regulations popping up offering some restrictions to fishing in various places.”

Hatcheries in the Chehalis River Basin — which stretches from West Lewis County to Grays Harbor — annually use feed with antibiotics to help keep fish healthy, but warmer water contains less oxygen, stressing fish and making them more susceptible to diseases.

While Thiesfeld said while some waters in the basin have seen temperatures in the 70s, a south Thurston County hatchery is actually faring pretty well so far this summer. Hatchery staff say keeping temperatures under 65 degrees is key to fish health.

WDFW Skookumchuck Hatchery Manager James Dills said the hatchery outside Tenino isn’t seeing effects of the drought yet and that it should be OK through the summer, but it could face issues later.

“I’m in pretty good shape due to the water management of TransAlta,” he said.

While the Skookumchuck Reservoir — managed by TransAlta — is at lower-than-normal levels for this time of year, TransAlta is managing water release from the reservoir east of Bucoda for the drought conditions. It is also drawing water from deeper in the reservoir.

The deeper, cooler water is keeping daily monitored temperatures in the low 50s, which is good for fish health.

WDFW Region 6 Hatcheries Manager Randy Aho said most facilities in the basin are recording temperatures in the high 50s and low 60s.

However, at the Lake Aberdeen hatchery in Grays Harbor County, water flowing into the lake has neared 74 degrees, Thiesfeld said. Aho said water in the reservoir heats up quickly, so a siphon gravity intake was installed, which draws cool water from Wynoochee Lake.

“But we got on that a little late, so we had an issue with our coho, and we did have fish health issues with our coho onsite,” Aho said. “But other than that, that’s been our only issue in the Chehalis Basin.”

Aho said they lost some fish, but the program is still on track. “We think it’s going to be just fine, but there’s always a concern with a new operation,” Aho said.

At some sites, such as the Humptulips hatchery in Grays Harbor County, stop logs have to be put in each year to keep water levels up. If water levels get low enough, other areas may need to be sandbagged to divert water into intakes.

The Humptulips also heats up, but an intake was installed at Stevens Creek, which runs cooler in the summer.

Thiesfeld noted the Chehalis River itself has registered at higher than 70 degrees, where its adult spring chinook population is going to be more vulnerable.

“It would not surprise me if here in the next month, if temperatures stay this high, that we start to see some of those fish, you know, wink out on us,” Thiesfeld said.

Low stream flows also impact the ability of fish to migrate up stream.

Coho salmon and steelhead stay in the river as juveniles for one or two years. With potentially less summer habitat, the out migration will likely be fewer than normal and lead to a lower adult return, Thiesfeld said.

Thiesfeld expects there are more issues in the basin than the WDFW is aware of because they don’t have hatcheries on all the waterways, such as the South Fork Chehalis River.

The drought in Washington first affected snow-fed systems due to low mountain snowpack. Then when spring rainfall was below normal, other areas, including the Chehalis Basin, began seeing effects.

“All this winter and spring, as we were watching this drought unfold, we really didn’t think the Chehalis Basin was going to be affected because it’s a rain-based, groundwater-based system,” Scott said. “And seeing the flows dropping in the Chehalis was unexpected for me, and so it caught us who are planning at the state level pretty off guard.”

WDFW employees are also concerned that next year they will be facing the same issues as the El Nino that has developed isn’t likely to subside until maybe late winter, if not into next year.

“We’re starting to think about what’s going to happen if we have to do this again next year,” Scott said. “So where will we spend our money, and where will we change the effort we expend on things like patrolling streams?”

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