The past year was a good one for kokanee and trophy rainbow trout on Lake Pend Oreille, and for the anglers who pursue them. The fishery has steadily improved in recent years following intensive efforts to reduce predation on kokanee. Lake trout have been dramatically reduced thanks to angler harvest and lake trout netting efforts. As a result, kokanee survival has increased and the population has grown.

The increase in kokanee brought on two major management changes in 2013. First, a kokanee harvest fishery was reopened after a 13-year closure. Second, the Idaho Department of Fish and Game began rebuilding the trophy rainbow fishery that once existed.

The Angler Incentive Program for rainbow trout, which pays anglers $15 per harvested fish was discontinued, and a size restriction of only one rainbow over 20 inches per angler per day was implemented. These rule changes represent major milestones in the Pend Oreille fishery recovery effort. Anglers have played a huge role in turning this fishery around, so it's great to see them enjoying the benefits of the years of hard work.

Fish and Game monitors the kokanee population by midwater trawl netting and hydroacoustic surveys. The results in 2013 were very encouraging. More than 1.2 million mature kokanee survived to spawn.

Andy Dux, principal research biologist on Pend Oreille said 2013 represented one of the highest spawner returns seen in the past 40 years and was approximately a four-fold increase from 2012.

At the Sullivan Springs trap, which is the site where kokanee eggs are collected to fill the Cabinet Gorge Fish Hatchery, nearly 200,000 kokanee were handled, and 11.4 million eggs were collected.

"Compare that to 2007 and 2008, when the population bottomed out," Dux said. "In each of those years, only around 5,000 kokanee were handled and the total egg take was about a half million eggs."

Younger kokanee also were abundant, especially age-2 fish, which means another strong cohort of spawners for next year.

Dux predicts anglers will enjoy more great kokanee fishing in 2014.

Aggressive efforts to remove lake trout continued in 2013, marking the eighth year of this program.

Fish and Game has continued to use both the Angler Incentive Program ($15 reward) and commercial netting equipment to remove lake trout.

Together these actions have successfully reduced the size of the lake trout population to a level where it no longer is limiting expansion of the kokanee population.

This is a major achievement and possibly the best evidence to date that large-scale suppression of lake trout, with a resulting positive response from the kokanee population, is possible.

According to Dux, the challenge now will be to develop a long-term program for keeping these fish at low abundance into the future. Fish and Game will be evaluating options for a maintenance program that will allow for a gradual reduction of the annual netting effort.

"The goal is to reduce the netting effort (and cost) of this program over time, while still keeping lake trout at low abundance," Dux said.

Fish and Game expects to continue the Angler Incentive Program for lake trout into the foreseeable future, so the changes will be focused on netting activities.

This process will take time, but the fact that this transition is beginning after only eight years since starting the removal program is significant.

In addition to the decrease in lake trout, a decline in the mysid shrimp population may also be contributing to the kokanee resurgence.

These small freshwater shrimp have been present since the late-1960s and compete with kokanee for food (both eat zooplankton).

In 2012, the mysid shrimp population nearly collapsed and their density was almost 95 percent lower than the long-term average dating back to 1973. They remained at low density in 2013.

We are unsure what caused such a sudden drop in the shrimp population, but the past two years of low mysid density have almost certainly benefitted kokanee.

Another possible benefit to the decline in shrimp abundance could be a decrease in juvenile lake trout survival.

Time will tell how long it takes for mysids to rebound and how much kokanee have benefitted from the reduced decline, but the timing couldn't be better.

Fish and Game has several research activities planned for 2014, but most notable for anglers is a 12-month creel survey.

Biologists will be conducting angler counts and interviews throughout the year to estimate how much fishing effort and harvest is occurring for each of the fish species in the lake. This survey is very important for evaluating regulations and other management actions.

Anyone interested in learning more about the Pend Oreille fishery recovery program is invited to attend an upcoming public meeting. On Feb. 19, Fish and Game will present the most current information about the status of the Pend Oreille fishery and management efforts in the annual "State of the Lake" meeting and the Ponderay Events Center. The meeting will run from 6-8:30 p.m.

Jim Fredericks is the Idaho Department of Fish and Game's Panhandle region fishery manager.