2011 a historic year for Deschutes fish passageNovember 23rd, 2011
There are just a few weeks left in 2011, so here᾿s a year-end wrap up on downstream fish passage:
We had some exciting and historic milestones this year when fry planted upstream of Pelton Round Butte returned as adults. Read more on that topic below. But the big story of 2011 is yearling sockeye salmon. One of the goals of the anadromous fish reintroduction is to reestablish a sockeye salmon run up the Deschutes to the Metolius Basin through Lake Billy Chinook.
Background on Suttle Lake sockeye
Sockeye need a lake for rearing. Historically they have used Suttle Lake in the upper Metolius Basin and spawned in Link Creek between Suttle and Blue lakes. When Lake Billy Chinook was formed in 1964, the lake-type sockeye habitat in the basin increased dramatically.
Kokanee is the name give to sockeye that remain and rear in a fresh water lake. It has been theorized that the kokanee that naturally seeded Lake Billy Chinook came from Suttle Lake and that the original Suttle Lake sockeye would revert back to the anadromous form – sockeye – when safe downstream passage was provided.
More than 225,000 kokanee migrate in 2011
Well, in 2011, the fish seemed to go along with this theory. More than 225,000 kokanee migrated downstream and were collected in the Selective Water Withdrawal facility this year. This was nearly five times as many kokanee that migrated downstream in 2010. Much of the increase is likely due to a much larger kokanee spawning year-class in 2009 that produced yearlings in 2011.
Here’s a look at the numbers by species for the past two years:
Fish entering Selective Water Withdrawal facility
|2010 total||2011 total (through Nov. 17)|
|Spring Chinook smolts||44,017||30,684|
|Age 1-3 steelhead smolts||7,733||10,606|
|Yearling sockeye (kokanee)||49,734||225,763|
|Kokanee ‒ age 2 & older||25,330||175,559|
First upriver fish – Spring Chinook – shows up in May
It created a lot of excitement here at Pelton Round Butte to see the return of the first salmon and steelhead that were reared in the upper basin and passed downstream. From May through July 2011, we captured five adult and two jack spring Chinook.
First sockeye appears in July
In July and August, nineteen sockeye salmon came back. These were smaller fish that spent only one season in the ocean as opposed to the typical sockeye life history with two years in the ocean. These returning spring Chinook and sockeye were spawned at Round Butte Hatchery, and the resulting fry will be stocked upstream.
October, first steelhead
On Oct. 6, the first returning upriver steelhead showed up. These fish have the right maxillary bone clipped to mark them as originating upstream of Pelton Round Butte. We’ve since identified eight more returning adult steelhead that were originally planted upriver.
Steelhead returning this fall and winter migrated in 2010, so they have spent only one year in salt water and are relatively small. Next year, we will capture both one-ocean-year steelhead from the 2011 outmigration and larger two-ocean-year steelhead adults from the 2010 outmigration. Steelhead first start entering the Pelton Trap in October and continue coming through March, so we expect to capture many more in coming months.
For the current migration season, plans are for the Round Butte hatchery to use all the returning fish to produce fry for release upstream. That᾿s according to our partners with Oregon Fish and Wildlife and Warm Springs Tribes who manage these runs. We᾿re hopeful that, starting with the spring Chinook run in 2012, we᾿ll have enough upriver salmon and steelhead returning that we can begin passing them upstream.
‒ Don Ratliff, PGE senior biologist
Oregon Department of Fish and Wildlife biologist Mike Gauvin holds a steelhead that made Deschutes passage history, completing a round-trip to the Pacific Ocean on Oct. 6, 2011. It was the first returning adult steelhead from fish stocked and reared upstream of the Pelton Project that migrated downstream through the Round Butte Dam Selective Withdrawal Fish Transfer Facility.