Upper Klamath Lake, Oregon

Upper Klamath Lake is a hypereutrophic lake in southern Oregon. J. Eilers was the principal investigator on a paleolimnological study of recent changes in the lake. This study showed that Upper Klamath Lake has shown changes in the 20th century which are coincident with substantial changes in the watershed (pdf of manuscript). These watershed changes included draining of major wetlands, extensive grazing of livestock, substantial timber harvest, hydrologic modifications, and fertilizer contributions. The lake responded by exhibiting a massive increase in Aphanizomenon flos-aquae, which can represent over 95 percent of the summer phytoplankton biovolume. A similar study by the US Geological Survey found nearly identical findings.

Upper Klamath Lake has been the focus of intense controversy associated with the use of water stored in the lake for agricultural purposes and the declining population of two species of threatened and endangered suckers. However it is unknown how the suckers utilize the habitat within the lake and how much habitat is available. J. Eilers serves as principal investigator of a study funded by the US Bureau of Reclamation to quantify this nearshore habitat using hydroacoustics. The classification process involved three systematic paths around the lake supplemented by transverse paths extending from the shore out into the deeper area of the lake.