Comparison of Brook Trout Abundance and Distribution in Vermont’s Streams between the 1950s and the 2000s

Jud F. Kratzer^1,*, Peter McHugh², Richard Kirn³, and William H. Eldridge¹

¹Vermont Fish and Wildlife Department, 374 Emerson Falls Road, Suite 4, St. Johnsbury, VT 05819. ²California Department of Fish and Wildlife, 3637 Westwind Boulevard, Santa Rosa, CA 95403. ³Vermont Fish and Wildlife Department (retired). *Corresponding author.

Northeastern Naturalist,Volume 28, Issue 2 (2021): 189–201

Abstract
Salvelinus fontinalis (Mitchill) (Brook Trout) abundance and distribution have declined in much of their native range in the eastern United States, with most intact habitats concentrated in the northern states. We used stream electrofishing data from the 1950s (1952 to 1960) and the 2000s (2005 to 2016) to quantify changes in the abundance and distribution of Brook Trout in Vermont over the last half century. We also investigated whether Brook Trout’s co-occurrence with Salmo trutta (Brown Trout) and Oncorhynchus mykiss (Rainbow Trout) in the 1950s influenced their abundance in the 2000s and, further, whether or not the distribution or abundance of non-native trout has changed appreciably since the 1950s. Overall, Brook Trout abundance was higher in the 2000s than in the 1950s. Increased abundance was driven by increases in young of year (YOY), which was not related to the occurrence of non-native trout. Although present at fewer sites in the 2000s, non-native trout densities remained unchanged. Brook Trout distribution at the HUC-12 watershed scale was essentially identical during both time periods. This study confirms previous modeling efforts, which indicated that Brook Trout have a higher probability of persisting in higher latitude, higher elevation, and less-developed regions.

Download Full-text pdf (Accessible only to subscribers. To subscribe click here.)