The following is quoted from the Oregon Department of Fish and Wildlife Internet site. This site features the weekly recreation report, the latest department news releases and much more.

KOKANEE AND SOCKEYE SALMON (ONCORHYNCHUS NERKA) SPECIES OVERVIEW Sockeye and kokanee are the anadromous and resident life histories of Oncorhynchus nerka, respectively. This species requires a lake for part of it's life cycle. Spawning may occur along lake shorelines or in stream gravels, but fry always migrate to lake environments soon after emergence and occupy this habitat during their stay in fresh water. Adult spawning behaviors in lake inlets, outlets, or along lake shorelines; juvenile migration behavior upstream or downstream into lakes; and anadromony behavior all appear to have a genetic component. Populations with different life histories existing in sympatry may be, but are not necessarily, reproductively isolated from each other. The O. nerka range in North America extends from the Klamath River in California to Point Hope in Alaska, with a few disjunct populations extending to Bathurst Inlet in the Arctic Ocean. In Asia, the species is found from northern Hokkaido, Japan, to the Anadyr River, Russia. Kokanee are found over most of the species range and occur both sympatric with sockeye and in lakes to which anadromous fish no longer have access, including both naturally and artificially blocked lakes. Kokanee also have been introduced outside of their natural distribution in Oregon and elsewhere in North America and have established many naturalized populations. Both kokanee and sockeye were historically present in two basins in Oregon -- the Grande Ronde River in the Snake River Basin and the Deschutes River in the lower Columbia River Basin. Sockeye are extinct in the Grande Ronde and persist only at extremely low levels in the Deschutes due to the construction of artificial barriers including Pelton and Round Butte dams in the Deschutes and a water storage and diversion structure at the outlet of Wallowa Lake in the Grande Ronde. Kokanee are still present in both basins.

CRITERIA FOR DESCRIBING GENE CONSERVATION GROUPS The species Oncorhynchus nerka, including both resident (kokanee) and anadromous (sockeye) life histories are native to two stream/lake systems in Oregon -- the Grande Ronde River and Wallowa Lake system in the Snake Basin and the Deschutes River and Suttle Lake system in the lower Columbia Basin. The sockeye life history is extinct in the Grande Ronde, but persists in very small numbers in the lower Deschutes. A third potential group consisting strictly of kokanee is present in Odell Lake located in a closed basin that historically connected to the upper Deschutes River. This group may be introduced, although historical records of hatchery plantings and natural spawning observations are inconclusive. The National Marine Fisheries Service (NMFS) is currently conducting a biochemical and meristic survey of O. nerka regionwide that includes samples from all of Oregon's populations except the remnant Deschutes sockeye. Efforts to obtain tissue samples from the sockeye have been unsuccessful because of the low number of fish. The description of a Wallowa Lake gene conservation group and a Deschutes gene conservation group for this species is therefore based on the substantial geographical distance between the two basins and on observed differences in appearance, especially spawning coloration between the groups. The Deschutes group includes a remnant sockeye population that may spawn below Pelton/Round Butte dams. At least two kokanee populations are present above the dams, one that migrates between Lake Billy Chinook and the Metolius River and one that migrates between Suttle Lake and Link Creek. These are currently isolated from each other by man- made barriers that date to the early 1900s. Both of these kokanee populations are characterized by a distinctive blue- black body coloration during spawning. Preliminary results from the NMFS biochemical survey indicate that both Deschutes populations are unique compared to other Columbia Basin O. nerka, and that the two populations have diverged from each other (Robin Waples, personal communication). Both are inlet spawners, but the Suttle Lake/Link Creek population spawns two to three weeks later than the Lake Billy Chinook/Metolius population. The sockeye probably spawn at about the same time as the Lake Billy Chinook/Metolius group, based on their time of arrival at the hatchery trap. The Odell Lake group is currently grouped with the Deschutes until further information becomes available. The population contains an unusual amount of polymorphism in spawning coloration, including red, green mottled , striped and blue-black members. Body shape is also highly variable. This level of polymorphism seems unusual for a wild population and is more typical of naturalized populations founded from multiple sources. Odell Lake is naturally isolated by a lava dam in the upper Deschutes and multiple waterfalls in the midmainstem. Historical records do not demonstrate the presence of wild kokanee in any other upper Deschutes lake such as Cultus Lake or Crescent Lake. This group may be declared a natural rather than a wild population, but this decision will be deferred until analysis of the biochemical survey is completed. The Wallowa kokanee includes two populations, an inlet spawning group and a shoreline spawning group. The shoreline spawners spawn nearly a month later than the inlet spawners and appear to be larger. Preliminary results from the NMFS biochemical survey indicate that the two populations differ from each other (Robin Waples, personal communication). These fish have either the more typical red body/green head spawning coloration or a mottled green color pattern.

STATUS REPORT Listing Status This species is not listed under the state or federal Endangered Species Acts.

SPECIFIC STATUS CONDITIONS GRANDE RONDE/WALLOWA LAKE: The sockeye morphology became extinct in the Grande Ronde as the result of a barrier constructed at the outlet of Wallowa Lake in 1916. The barrier eliminated sockeye access to Wallowa Lake. Sockeye continued to be observed in Wallowa River below the lake until the early 1930s, when they become extinct. Two kokanee populations exist in Wallowa Lake, an inlet-spawning population and a shore spawning population. The shore population is a new population discovered in 1993. The two populations are reproductively isolated from all other kokanee. Kokanee population trends and age-class distribution have been monitored annually by creel sampling and inlet population age-class sampling since 1970. The populations fluctuate over time, but show no particular long-term trend. Models to estimate population sizes are being evaluated, but the spawning populations are known to include hundreds of fish based on observations on the spawning grounds. Mysis shrimp were introduced into Wallowa Lake in the 1960s. Although the shrimp are eaten in small amounts, they do not appear to be used as a primary kokanee food item and there is concern that they may be affecting the population dynamics of native zooplankton. Zooplankton populations have been monitored annually since 1986. Hatchery kokanee were planted in this population historically. The hatchery program was discontinued for a period, then reinstated in 1990 using Paulina Lake stock to evaluate the feasibility of using hatchery fish for harvest. Evaluation of catch contribution of these hatchery fish has been conducted annually through angler creel surveys. Preliminary results to date indicate hatchery kokanee have contributed less than 3% to angler catches through 1994. All hatchery fish have been marked. The hatchery fish are of mixed origin and less than 5% can naturally spawn with the wild fish. Marked fish were observed spawning in the shoreline population for the first time in 1993. No hatchery fish have been observed in the inlet population, but sampling of the population has been limited. Hatchery releases were discontinued after 1994. Preliminary results from the NMFS biochemical survey suggest that there has been some hatchery introgression in both populations, most probably from the historical hatchery program (Robin Waples personal communication).

DESCHUTES/METOLIUS RIVER/SUTTLE LAKE: The sockeye morphology continues to persist at extremely low levels in the Deschutes River group. Sockeye were blocked first from Suttle Lake by the construction of a barrier at the lake outlet in the early 1900s. The life history persisted by either spawning in the Metolius River and rearing in the Deschutes or in the Columbia, or outmigrants escaped annually over the Suttle Lake barrier. Sockeye spawning runs continued into the Metolius until the construction of the Pelton/ Round Butte dam complex in the 1960s. A kokanee population now rears in Lake Billy Chinook, the reservoir behind the dams, and migrates to spawn in the Metolius River. A few sockeye continue to return to the base of the dam complex. Sockeye are observed only when they enter the hatchery trap at the base of the dam. Seven sockeye were captured in the trap in 1992, one was captured in 1993 and fourteen were captured in 1994. The current source of the sockeye is uncertain. They may be from outmigrating kokanee that escape over the Pelton/Round Butte complex, strays from elsewhere in the Columbia Basin, or the sockeye may spawn below the dams and rear in mainstem Columbia River reservoirs. The two Metolius River kokanee populations are currently isolated from each other by artificial barriers. These barriers are small and it is technically feasible to provide passage. Preliminary biochemical data suggests that the populations have diverged from each other, possibly as a result of the isolation caused by the barriers (Robin Waples, personal communication). The kokanee populations are also isolated from the sockeye population. Passage for sockeye around Pelton and Round Butte dams is technically more difficult. Distance would probably isolate all Deschutes populations from other O. nerka, even if artificial barriers were absent. The spawning run of kokanee in Suttle Lake into Link Creek was intentionally blocked for a number of years to decrease population size and increase size of fish for harvest purposes. Limited spawning did occur however in lower Link Creek below the weir. The population declined as a result. The blockage weir on Link Creek was removed and natural reproduction resumed in 1991. The spawning population includes hundreds of fish, based on observations on the spawning grounds. The Metolius/Lake Billy Chinook population is monitored in angler creel checks on Lake Billy Chinook (since 1990) and spawner surveys on mainstem Metolius river and tributaries, initiated in 1994. Observations of the spawning population indicate that it includes thousands of fish. Historical hatchery programs occurred in these populations, but no hatchery fish are currently being released in Lake Billy Chinook/Metolius or Suttle Lake/Link Creek. Hatchery programs in the basin are located in Lake Simtustus (between Pelton and Round Butte dams), and Craine Prairie Reservoir and Paulina Lake in the upper Deschutes. Naturalized populations from past hatchery programs are present in some other upper Deschutes reservoirs and lakes. The hatchery fish can be distinguished from the wild populations in the Deschutes due to the unique color pattern of Metolius fish, and it does not appear that hatchery fish are entering the kokanee populations. Preliminary biochemical data also indicates that there has been no hatchery introgression (Robin Waples, personal communication). It is possible that hatchery kokanee escaping from Lake Simtustus contribute to the lower Deschutes sockeye population, although based on Oregon Department of Fish and Wildlife inventories, most of the kokanee (up to 80% as observed in creel surveys in recent years) in Lake Simtustus are naturally produced fish passing downstream from Lake Billy Chinook. Escape of other species of hatchery fish from Lake Simtustus occurs, but apparently only in small amounts. The Odell Lake kokanee population may be a natural, rather than a wild population. Kokanee have been observed naturally spawning in the lake since the early 1940s; early hatchery records are inconclusive about planting prior to that time. If it is a wild population, it is naturally isolated by the lava dam that isolates the Davis/ Odell Lake system from the rest of the upper Deschutes Basin.

ACTIONS UNDER WAY Annual population monitoring and hatchery program evaluation will continue in Wallowa Lake. The feasibility of developing a local Wallowa Lake broodstock will be investigated. Mysis and native plankton monitoring will continue. Tissue samples for genetic analysis have been collected from all Oregon populations including the Odell Lake population and the Paulina Lake hatchery population, and are currently being analyzed by the National Marine Fisheries Service in Seattle. Efforts to collect fin-clip tissue samples from sockeye have been unsuccessful to date, but will continue.