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New Water Chemistry Strategies by IDFG
Increase Survival of Snake River Sockeye Smolts

by Staff
Columbia Basin Bulletin, June 15, 2018

(Katherine Jones) Sockeye returning to Redfish are weighed, tagged and dna samples taken at the Eagle Fish Hatchery. A NOAA Fisheries Northwest Fisheries Science Center report on juvenile salmon released last year found that survival of juvenile sockeye salmon -- both hatchery and wild -- from Lower Granite Dam on the Snake River to Bonneville Dam on the Columbia River was just 17.6 percent, the fourth lowest survival estimate from 1998 to 2017.

That was the third year in a row for low sockeye survival, listed as endangered under the federal Endangered Species Act. In 2016 survival was estimated at 11.9 percent and 2015 was 37.3 percent. The highest survival was 82 percent in 2008 and the average is 39.2 percent.

Much of the cause for the low survival begins far upstream at a new hatchery near American Falls, Idaho, according to Paul Kline and Christine Kozfkay of Idaho Department of Fish and Game. The problem is a difference in water chemistry -- hard water -- between a newly constructed smolt production facility at the Springfield Hatchery and smolt releases into Redfish Lake Creek in the Sawtooth Valley.

That water quality difference is "responsible for inducing stress levels in smolts that are high enough to cause significant post-release mortality," according to a June 5 Council Memorandum

Kline and Kozfkay briefed the Northwest Power and Conservation Council's Fish and Wildlife Committee Tuesday, June 12, at its meeting in Portland, on two strategies Idaho is adopting to counter the water chemistry difference, and they are seeing positive results and survival rates to Bonneville Dam as high as 50 percent.

"This is really good news," said Bill Booth, Idaho Council member. "Our ultimate goal is to restock Redfish Lake."

The estimated cost of a large scale water softening system at the hatchery exceeded the cost of the new hatchery, Kline said, so IDFG has come up with two potential solutions.

The first is to transfer the smolts from the Springfield Hatchery to the Sawtooth Hatchery for an acclimation period prior to release into Redfish Lake Creek and the upper Salmon River.

The second is the use of a commercial resin to soften water in trucks that transport the smolts from the Springfield Hatchery to Redfish Lake Creek.

NOAA's 2008 biological opinion for the Federal Columbia River Power System called for the production of 500,000 to 1 million fish at a new facility. That facility, the Springfield Hatchery, was dedicated in September 2013 and the first shipment of sockeye eggs from the Eagle Hatchery near Boise arrived later in 2013. The Eagle Hatchery, according to Kline, is the primary captive broodstock station in Idaho.

Nearly 215,000 smolts were released from the Springfield Hatchery into Redfish Lake in 2015, 540,665 in 2016 and 734,492 in 2017, according to Kozfkay.

Prior to these releases, survival at Lower Granite Dam was about 55 percent, but with the addition of the Springfield Hatchery smolts, survival dropped to 30 percent in the years 2015 -- 2017. Survival at Bonneville was about 32 percent prior to the Springfield releases and only 4 percent afterwards, she said.

"Unfortunately, in 2017, we saw increased numbers (estimated at 100K) of dead or moribund fish in the release location up to two days post planting," Kozfkay said.

Water alkalinity and hardness at the hatchery compared to smolt release points shows a huge disparity. Alkalinity at the hatchery is 194 -- 202 milligrams per liter, whereas alkalinity in Redfish Lake Creek is 1 -- 8 mg/L and in the Salmon River 66 mg/L. Water hardness at the hatchery is 234 -- 248 mg/L, while it is 11 -12 mg/L at Redfish Lake Creek and 68 mg/L in the Salmon River.

The pH is much closer, with pH at the hatchery of 7.7 -- 7.75; Redfish Lake Creek is 7.41 -- 7.72 and at the Salmon River pH is 7.94.

In 2017, prior to testing the two strategies, blood hormone testing (specific plasma cortisol) identified that stress factors continued to act on smolts following release to Redfish Lake Creek, Kozfkay said. Cortisol is partially responsible for the fight or flight response in fish.

Cortisol levels prior to loading onto trucks at Springfield were at low background levels, but after loading cortisol levels spiked. Just before release -- following a five hour truck trip -- they were slightly lower but essentially the same. Four hours after release, they spiked considerably and stayed high even 24 hours after release, she said.

"Our release plan was based on a number of principles: 1) spreading the risk and 2) documenting the physiological response and survival differences," Kozfkay said.

Some 240,000 presmolts were transferred from the Springfield Hatchery to the Sawtooth Hatchery for acclimation in the fall of 2017, she said. There they underwent blood chemistry tests to investigate the stress response, finding that fish returned to non-stressful levels. These fish were released into Redfish Lake, over-wintered and emigrated this spring. Their survival to Lower Granite Dam was 75 percent, while the travel time was 7.5 days.

The majority of smolts were transferred to open raceways at the Sawtooth Fish Hatchery and acclimated for about four weeks. Half were transported to Redfish Lake Creek for release and the other half released directly to the Salmon River at the hatchery. Overall, these fish saw 69 percent survival and a travel time of 8.2 days.

A small group of 3,000 fish were transported from the Springfield Hatchery to Redfish Lake Creek and the truck was retro-fitted with a filtering system to soften the water during the 5 hour transport. Some 53 percent of this release survived to Lower Granite with a 9.3 day travel time.

Lastly, a control group of about 45,000 smolts was transported from the Springfield Hatchery and released directly into Redfish Lake Creek without any acclimation. As expected, this group's survival was just 18 percent and travel time was 9.1 days.

"Survival from release to Bonneville Dam was also high and greater or equal to what we've seen in the past with other hatchery releases," Kozfkay said. "So, not only did the strategies appear to be successful, but the timing of release and environmental conditions (spill, flow) likely improved survival."

Looking at cortisol levels in the bloodstream of the smolts after release, they found the direct release group from Springfield to Redfish Lake Creek to have the highest cortisol levels and while they were trending down, they were not lower than 100 ng/mL after 48 hours. Both acclimated release groups showed lower levels of cortisol which dropped further after 48 hours.

"Acclimation to Salmon River water at Sawtooth hatchery seems to be the most effective strategy to address water chemistry differences but other strategies may hold promise," Kozfkay concluded.

Related Pages:
Count the Fish by Government Accounting Office, GAO-02-612, Salmon and Steelhead Recovery Efforts
With Temps Rising, Corps Cools Snake River With Dworshak Water To Aid Endangered Snake River Sockeye by Staff, Columbia Basin Bulletin, 7/13/18
Corps Report On 2015 Columbia/Snake Warm Water, Fish Die-Off Will Discuss Actions To Avoid Repeat by Staff, Columbia Basin Bulletin, 4/1/16
Snake River Sockeye: Lowest Return Since 2007, Captive Broodstock Program Increases Spawners by Staff, Columbia Basin Bulletin, 9/11/15
NOAA Fisheries Releases Snake River Sockeye Salmon Recovery Plan: 25 Years Of Actions At $101 Million by Staff, Columbia Basin Bulletin, 6/12/15

Related Sites:
2017 Juvenile Salmon/Steelhead Survival In Snake/Columbia: Fish Take Hit In McNary To John Day Reach by Staff, Columbia Basin Bulletin, 10/6/17
With Run Downgrade, Summer Chinook Fishing Below Bonneville Dam Ends Early; Sockeye Above Forecast by Staff, Columbia Basin Bulletin, 6/29/18

New Water Chemistry Strategies by IDFG Increase Survival of Snake River Sockeye Smolts
Columbia Basin Bulletin, June 15, 2018

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