Thesis Title: Paleolimnological Reconstruction of  Westslope Cutthroat Trout (Oncorhynchus clarki lewisi)  in Alpine Lakes using a Next-Generation Sequencing Platform (link; co-supervisors: R. Vinebrooke, M. Taylor)

Author: Hedin Nelson-Chorney


Understanding historical species distributions is vital to the conservation and restoration of native species, yet such information is often qualitative.  Here, we show that the paleolimnological history of threatened freshwater fishes can be reconstructed using species diagnostic markers amplified from environmental DNA deposited in lake sediments (lake sediment DNA).  This method was validated through the detection of lake sediment DNA from non-native trout (Yellowstone cutthroat trout; Oncorhynchus clarkii bouvieri), which corroborated historical records of human-mediated introductions.  Moreover, we discovered native trout (westslope cutthroat trout; Oncorhynchus clarkii lewisi) lake sediment DNA that predated human-mediated introductions of freshwater fishes in a watershed with high topographical relief.  This unexpected result revealed that the population was of native origin and requires immediate conservation protection.  Our findings demonstrate that lake sediment DNA can be used to determine the colonization history of freshwater fishes and the structure of ecosystems, aiding in the identification of native ranges, novel native diversity, and introductions of non-native species.

Posted in Conservation of Freshwater Fishes, Restoration and Reclamation and tagged .