Operation Lava Island Falls Fish Rescue

Volunteers conducted a fish rescue operation over several days in mid-October, after reduced flows stranded fish in a mile-long side channel at Lava Island Falls along the Upper Deschutes River.

The event was organized by the Deschutes River Conservancy, with help from volunteers and staff from fisheries and environmental consulting firm Mount Hood Environmental.

Several years back, hikers along the Deschutes River Trail complained about dying fish along the side channel at Lava Island. The fish became stranded as irrigation management reduced flows in the river to the point where the channel became isolated from the main flow. One year, the stench was significant. That set the wheels in motion for a recovery operation, which has led to the efforts coordinated by DRC.

For the rescue operation, time was of the essence, as the ephemeral pools would only last so long before they disappeared, draining into the lava substrate below or becoming too small to sustain the fish. Once cut off from the main channel, some of the pools might only last for about 12 hours.

“Today has been great, we’ve had excellent volunteers help out, be exactly where they need to be, and willing to jump in and get wet or carry buckets and do all the hard work,” said Gina Maag-Klobas, a biological technician with Mount Hood Environmental.

Some smaller pools were electrofished by using a backpack shocker to stun the fish, which would then float up to the surface. Volunteers with nets would then scoop up the fish and place them in buckets with battery-powered aerators for transport up to a processing location at the Lava Island boat ramp. There the fish were counted by species and placed into new buckets before being released back into the main channel of the river. Volunteers collected a total of 6,281 fish during the rescue operation.

“We had about 90 volunteers sign up, and as soon as the shifts opened up, the community met the need,” said Marisa Hossick, Deschutes River Conservancy communications director.

Volunteer Tom Hill spent the day helping on the project and even signed up his daughter, Sara Hill, who was visiting for several months before starting a job with the Montana Watershed Council.

“I’m a fly fisherman and I support the Deschutes River Alliance and saw the email for the volunteers to sign up,” said Hill, who lives in Bend. “The volunteers were divided into several groups, and those of us with chest waders, we got to do the netting.” Hill scooped up numerous fry and fingerlings but did see several fish in the 10- to 12-inch range.

“When they were zapping the fish and we were out with the nets, it was a kick in the pants, it was fun!”

Most of the fish collected were rainbow trout, but the group also found German brown trout, sculpin and three-spined stickleback.

“We control the flows out of Wickiup and so when irrigation season shuts down, we shut down the water,” said Josh Bailey, irrigation manager for the North Unit Irrigation District, the second largest irrigation district in the state. NUID works with numerous other irrigation companies that rely upon the Deschutes River for irrigation water, as well as many other stakeholders and public agencies to facilitate the fish rescue operation.

With the finalization of the Deschutes Basin Habitat Conservation Plan in 2020, flows coming out of Wickiup in the winter will increase to 300 cfs from the current 105 cfs level. “We anticipate that with those flows, and natural flows after 2029, we won’t have to do this rescue anymore because flow rates will be high enough to sustain this channel,” added Bailey.

This article appears in Source Weekly October 31, 2024.