Watch Out for Early Ice

By Ned Horner, Regional Fisheries Manager, Idaho Department of Fish and Game Although most anglers have heard of the major changes in fishing regulations on Lake Pend Oreille, many are still wondering exactly what the changes were, what those changes were based on, and what more is being done to help rebuild the kokanee population. The Idaho Fish and Game Commission recently passed emergency rule changes for Lake Pend Oreille and the Clark Fork River to give anglers the opportunity to harvest more rainbow and lake trout (mackinaw), while restricting harvest of kokanee. Fishing for all species is now allowed year round in both Lake Pend Oreille and the entire Clark Fork River. The rainbow limit was increased to six fish, while there is no limit for lake trout (mackinaw). Kokanee were closed to harvest and bull trout remained closed to harvest. There were no changes in the cutthroat limit of two fish. What all this means is that an angler is allowed a general trout limit of six fish, of which no more than two can be cutthroat. If you had one cutthroat, you could harvest five more rainbow. Any lake trout you catch are in addition to your general limit of six other trout (rainbow, brown, cutthroat). So why the switch from trophy rainbow management to a harvest-oriented trout fishery? Kokanee in Lake Pend Oreille are in serious trouble. We are currently looking at the lowest population levels ever recorded. We only had 280,000 age 3 fish, 80,000 age 2 fish and 250,000 age 1 fish in the fall 1999 population estimate. The average number of kokanee (during the last 22 years of trawling) in these same year classes is 730,000 age 3, 1.23 million age 2, and 1.45 million age 1 fish. Future spawners are going to be scarce and there is no way to "make" more of these older age class fish. We can only try to save what is left. Survival rates of the kokanee most commonly eaten by predators (age 1 to 2 year old fish) have dropped from the typical 80+ percent to only nine percent. This is evidence that a predator bottleneck is present. Even with a big release of hatchery fry this year, if predators are not reduced, they will essentially consume all the available forage and leave nothing for the future. Rainbow are being targeted because they are responsible for most of the kokanee predation (83 percent of the total). Rainbow are the most numerous predator in Lake Pend Oreille (15,545 rainbow, 12,928 bull trout, and 2,100 lake trout over 17 inches) and they rely almost exclusively on kokanee. Bull trout and lake trout eat a wider variety of food items. Rainbows grow faster than bull trout or lake trout, consuming more kokanee to fuel that growth. Although bull trout accounted for 14 percent of all kokanee consumed, harvesting bull trout currently is not an option due to their listing as a threatened species under the Endangered Species Act. Liberal regulations on lake trout since 1992 have already reduced their population and they were a minor part of kokanee consumption (three percent). To reduce predation of kokanee, the rainbow population needs to be reduced. Why target rainbow spawners in the Clark Fork River? We knew that opening the Clark Fork River would be highly controversial, based on petitions urging the Department to close the fishery back in the early 1970s. At that time, the rainbow fishery w