Incorporating Climate, Disease and Invasive Species into the Conservation of a First Food, Klamath Redband Trout Active

Climate change has the potential to magnify existing problems in conservation, such as invasive species and disease. This threat is particularly severe in the Klamath Basin, where the fish parasite Ceratonova shastais making national headlines for killing salmon, and invasive trout have extirpated populations of native trout. The Klamath Basin is slated for one of the largest restoration projects in human history involving the removal of 4 mainstem dams. The success of this massive effort will likely depend on how climate, disease, and invasive trout combine to affect fisheries. However, there is currently no data available to incorporate these important interactions into conservation planning. This dearth of information is particularly challenging for the Klamath Tribes who rely on native redband trout for their last remaining subsistence fishery and advise several restoration plans.

Our ongoing collaboration with the Klamath Tribes has revealed a potential silver lining associated with disease and climate change. Under mild environmental conditions, C. shasta appears to kill invasive trout but not native trout and salmon. However, if temperatures get warm enough, C. shastacan kill native fish too, generating devastating fish kills. Thus, acritical challenge for conservation is to identify the range of optimal temperatures where C. shasta benefits native fish by serving as ‘the enemy of their enemy’. Further, managers need to know where this range of temperatures occurs both now and in a warmer future, to guide restoration and invasive species management. This project will provide conservation plans with maps of invasive trout and C. shasta and forecast where their interactions will create opportunities for managers, both now and in a warmer future. These products will significantly inform one of the largest restoration efforts in history.