Does length-at-age of burbot differ between two isolated and trophically dissimilar basins of Lake Champlain?

• Main Author: Paribello, Emily
• Format: Text
• Language: unknown
• Published: UVM ScholarWorks 2023
• Subjects: Burbot; Lota lota; lota
• Online Access: https://scholarworks.uvm.edu/src/2023/completepresentationlist/168

Burbot (Lota lota) is a piscivore native to higher latitude cold freshwater systems across the globe, including Lake Champlain, but little is known about their ecology and role as a top predator. Lake Champlain (1,250 km2 ) is highly fragmented, with five ecologically distinct basins. Burbot occur throughout the lake, including two basins which differ in bathymetry, productivity, and prey availability. The Main Lake is deeper, less productive, and contains higher densities of rainbow smelt (Osmerus mordax) and Mysis diluviana than the Inland Sea. We examined burbot diet and growth rates in each basin. We estimated age and diet composition for >100 burbot captured by gillnet and bottom trawling in summer and fall of 2021 and 2022 to quantify differences in burbot ecology through ontogeny and between the two distinct basins. Burbot ages were estimated by two readers, and an age-length key was constructed and applied to >200 burbot captured between 2015-2021. Results from our work will inform ongoing efforts to model coldwater pelagic food webs of Lake Champlain to better understand predator-prey dynamics in large lakes.