Bathymetry, morphology, and lakebed geologic characteristics of potential Kokanee salmon spawning habitat in Lake Pend Oreille, Bayview and Lakeview quadrangles, Idaho

Kokanee salmon (Oncorhynchus nerka) are a keystone species in Lake Pend Oreille in northern Idaho, historically
supporting a high-yield recreational fishery and serving as the primary prey for the threatened native bull trout (Salvelinus
confluentus) and the Gerrard-strain rainbow trout (Oncorhynchus mykiss). After 1965, the kokanee population rapidly declined
and has remained at a low level of abundance. Lake Pend Oreille is one of the deepest lakes in the United States, the largest lake
in Idaho, and home to the U.S. Navy Acoustic Research Detachment Base. The U.S. Geological Survey and Idaho Department
of Fish and Game are mapping the bathymetry, morphology, and the lakebed geologic units and embeddedness of potential
kokanee salmon spawning habitat in Lake Pend Oreille. Relations between lake morphology, lakebed geologic units, and substrate
embeddedness are characterized for the shore zone, rise zone, and open water in bays and the main stem of the lake. This detailed
knowledge of physical habitat along the shoreline of Lake Pend Oreille is necessary to better evaluate and develop kokanee
recovery actions.