Quantifying Pelagic Food Web interactions in Lake Tahoe-In search of a niche for re-introduction of Lahontan Cutthroat trout
July 2012 - September 2015
- .S. Fish & Wildlife Service, Lahontan NFHC
Despite past research on trophic relationships within Lake Tahoe, important information gaps remain concerning temporal-spatial interactions among pelagic fishes and invertebrates, especially with respect to how these interactions might influence the re-introduction of Lahontan cutthroat trout into the lake. We focused on identifying and quantifying the key pelagic food web interactions related to kokanee, other planktivorous fishes, mysids, and zooplankton to synthesize with previous data on predator-prey interactions with lake trout, in order to improve our understanding about the contemporary food web. This analysis supported hypotheses regarding the important trophic role of mysids as a predator regulating crustacean zooplankton, a competitor limiting growth and production of kokanee, and as an essential energy source supporting the predatory lake trout population. Thermal stratification mediates the spatial-temporal distribution and overlap of predators, prey, and competitors and thus can potentially influence the timing and magnitude of trophic interactions among key pelagic fish and invertebrates.