IDFG reviewing kokanee population impacts

COEUR d'ALENE - With this year's high runoff, Idaho Fish and Game doesn't know what the impacts might be on Lake Pend Oreille and Lake Coeur d'Alene kokanee populations.

However, according to an email update from Regional Fishery Manager Jim Fredericks, the department should have more answers in a couple months.

History has shown that a large percentage of kokanee (as well as Chinook in Lake Coeur d'Alene) may be lost during extremely high runoff years, Fredericks wrote. In the 1996 flood, for example, about 90 percent of the age-1 kokanee in Coeur d'Alene died, leading to an imbalance in the population.

Significant losses occurred in Pend Oreille as well, though the direct relation to the flood isn't as clear, Fredericks noted. This year, anglers and fish sampling crews downstream of Albeni Falls Dam have been seeing lots of kokanee, so IDFG does know that some fish have headed downstream.

That said, Fredericks is still optimistic, he wrote.

The '96 flood was earlier in the year as opposed to the "normal" runoff period. In fact, 1997 was also a high flood year, but the flood came later in the spring. Although losses did occur, they weren't as high as in 1996.

This year's runoff is exceptionally late and of a long duration, Fredericks wrote, as opposed to an early, short-duration flood. Hopefully the effects will be much different than that of 1996.

Anglers fishing Lake Coeur d'Alene are finding plenty of kokanee throughout the lake, he added, which is encouraging.

The department will have to wait until hydroacoustic and trawl estimates are available in late August/early September to see how each of the kokanee age-classes have been affected.

The field season is now in full swing, and IDFG is working on several projects this summer, Fredericks wrote, including:

• Evaluation of channel catfish stocking program in various lakes around the region (Cocolalla, Hauser, Fernan)

• Priest River fish population survey

• St. Maries River fish population survey

• Pygmy whitefish surveys in Priest and Spirit lakes

• Creel survey of Hauser and Fernan lakes