This article was published on: 10/6/22 11:56 AM
Central Oregon’s Crooked River became the first Oregon river the state has closed to angling specifically due to drought-related low flows that could result in major impacts on fish as well as on efforts to reintroduce salmon and steelhead to the river.
The Ochoco Irrigation District dropped flows downstream of Bowman Dam from about 180 cubic feet per second to just 10 cfs beginning Sept. 14, an 18-fold drop in river flow. The district would normally drop flows in the river this time of year as irrigation demand also drops, but this year the drop is precipitous. The Prineville Reservoir that backs up behind the dam this week is just 10 percent full, the lowest level on record, according to the Bureau of Reclamation, which owns the dam and says that multiple years of drought is the major contributing factor.
The Oregon Department of Fish and Wildlife closed the river to angling at least until Oct. 31, the agency said in a news release. It said the closure is due to “ongoing drought and low water” and did not announce a reopening date.
“After several years of persistent drought in Central Oregon, streamflows and reservoirs in this region have reached historic lows,” ODFW said. It explained that during the summer water is released from both Prineville and Ochoco reservoirs into the Crooked River and Ochoco Creek for irrigators downstream. “These releases also serve to maintain adequate flows for resident game fish, including native redband trout and mountain whitefish.” The Ochoco Reservoir is completely empty.
The drop in flow from the reservoirs is resulting in a “significant decrease in available habitat for resident gamefish species,” ODFW said. “Fish will concentrate in the remaining pool habitats and face increased competition for food resources as well as being vulnerable to predators.”
The low water is also making it difficult for reintroduced adult Chinook salmon to migrate upstream into the Crooked River, according to Allison Dobscha, Portland General Electric spokesperson. PGE and the Confederated Tribes of the Warm Springs have reintroduced anadromous salmon and steelhead into Deschutes River tributaries upstream of its Pelton Round Butte hydroelectric project since 2010. The fish once thrived throughout the Deschutes River basin.
“Water in the Crooked River is extremely low, making it difficult for adult Chinook to migrate upstream of the Smith Rock area,” Dobscha said. “We’re currently tracking the movements of 81 radio tagged Chinook in the upper basin. So far, at some point during the summer or early fall, 15 of these tagged fish have been detected in the Crooked arm of Lake Billy Chinook or Crooked River. Only two of these were between the Opal Springs area and Smith Rock, and no radio tags have been detected above Smith Rock.”
Opal Springs Dam is just 4 miles upstream of the confluence of the Crooked River and Lake Billy Chinook.
“To dissuade Chinook from entering the Crooked during low flows, and to take advantage of good spawning habitat elsewhere, a portion of returning adult fish were released directly into the Metolius River and Whychus Creek,” Dobscha said. “While conditions in the Crooked remain poor, our biologists are hopeful about spawning in the Metolius and Upper Deschutes (including Whychus Creek). We have a record number of adult Chinook currently upstream of the project, and hope to see an influx of young fish, the offspring of these adults, heading toward the ocean through the Selective Water Withdrawal in 2024.”
PGE biologists this year released more than 350 Chinook salmon into Lake Billy Chinook, with 320 heading into the cold and steady flows of the Metolius River and 44 heading into Whychus Creek, a tributary of the upper Deschutes River. The total release is the highest number PGE and the Tribes have released since reintroduction began.
ODFW said that in similar low-flow situations it sometimes removes restrictions from angling in order to reduce the population of native fish to a level that the habitat can support.
“But ODFW data shows that the Crooked River fishery is dominated by catch and release anglers,” it said. “The fishing closure is meant to reduce additional stress and mortality caused by catch-and-release fishing that can occur under low flow and high density conditions.”
“We know the angling community in this area has already come out in support of a closure, with many anglers choosing to stop fishing voluntarily. We thank them for working with us to protect these fish,” said Jerry George, ODFW district fish biologist. “While the closure will help protect fish congregating in the limited waters available, ODFW still anticipates a reduction in the size of these fish populations due to the low flows. These populations can rebound relatively quickly if conditions improve, but that will require a lot more rain and snow than we have been seeing in recent years.”
No other Northwest state has closed recreational angling due to drought this year. The difference between Oregon and Washington is that Washington experienced cool and wet conditions during the spring and early summer, according to Harriet Morgan, climate coordinator for the Washington Department of Fish and Wildlife.
“Oregon is experiencing more severe drought than Washington state, likely explaining why those closures are occurring in Oregon and not in Washington,” Morgan said.
“While Washington state has experienced a dry August, the average monthly streamflow has ranged from normal to above normal for the majority of the state – exceptions include the Hoh River, Quinault, and Skookumchuck in western WA and the Little Spokane and Spokane River in eastern WA,” she said.
She added that in July 2022, the Washington Department of Ecology canceled the drought declaration that was extended for parts of eastern Washington earlier in the spring. Cool and wet conditions in spring/early summer improved water supply enough to warrant the removal of the declaration as no longer needed. In contrast, 17 counties in Oregon have received state drought declarations.
However, in July 2015, WDFW closed or restricted fishing in more than 30 rivers throughout Washington to help protect fish in areas where drought conditions had reduced flows and increased water temperatures. Fishing was closed in some waters and limited in others each day to the hours between midnight and 2 p.m., the coolest period of the day. These “hoot-owl” restrictions went into effect on rivers where fishery managers wanted to reduce stress on fish during the hottest time of day.
ODFW also implemented “hoot owl” restrictions on some rivers in July 2021, as did Montana Fish, Wildlife and Parks during the same month last year.
Like Oregon, Idaho will sometimes also use a salvage order, according to Lance Hebdon, Fisheries Bureau Chief at the Idaho Department of Fish and Game.
“In a nutshell we have not closed fishing due to drought or impacts of climate,” Hebdon said. “We occasionally have salvage orders issued for a specific stream or reservoir when the system is going to dry up or drop to levels that will not sustain fish. Salvage order would be the opposite of a closure. Our salvage orders suspend daily bag limits and most gear restrictions and encourages people to harvest fish before they perish due to environmental conditions.”
A recent study by IDFG found that catch-and-release angling in low and warm water does not harm the number of trout in a population.
The study found that mortality was 69% higher for trout landed at 73°F water temperatures than for those landed when waters were less than 66°F. These results suggest that higher water temperatures were indeed decreasing the survival of caught-and-released trout. However, catch rates were much lower (77% lower!) at the higher water temperatures above 73°F, and much better when temperatures were below 66°F.
So while mortality was higher at the hottest temperatures, the number of trout caught was much lower because it was much harder to catch fish at those warmer temperatures.