Large- and small- scale movement and distribution of acoustically tagged lake sturgeon (Acipenser fulvescens) in eastern Lake Erie

Abstract

Background Defining the spatial distribution, home range, and movement patterns of lake sturgeon (Acipenser fulvescens) is important to managers and decision makers given the large migration potential and potamodromous behavior exhibited by the species. A remnant population of lake sturgeon remains in the far eastern basin of Lake Erie and although recent efforts have estimated the population size, described the age distribution, and identified a primary spawning site no study to date has examined the spatial distribution or movements of individuals within this population. Between 2014 and 2018 we acoustically tagged 59 adult lake sturgeon, captured near the headwaters of the Niagara River, and monitored their large-scale movements throughout Lake Erie with the Great Lakes Acoustic Telemetry System and small-scale movements with a Vemco Positioning System near the headwaters of the Niagara River. After dividing Lake Erie into seven sections, we ran a multi-state mark recapture model to examine the movement rates into and out of the eastern most section of the lake. Within a heavily utilized lake section, near the headwaters of the Niagara River, we identified home ranges with our Vemco Positioning System for each season and year using averaged Brownian bridge movement models.Results Although some sturgeon demonstrated large-scale movements, traversing the entirety of Lake Erie, the majority of individuals spent their time in the eastern basin of the lake. Home ranges appeared to vary among seasons but were consistent across years with lake sturgeon selecting the northeastern, rocky, and shallow area of our array during pre-spawning and spawning seasons and leaving our array, or selecting a trough running along the northwestern portion of our array comprised of sand and bedrock, in the summer and fall seasons. Conclusions Documenting these large-scale movements aligns with previous findings that lake sturgeon on either end of the lake are genetically similar and demonstrates lake sturgeon in the eastern basin exhibit strong philopatry. Our small-scale movement models provide managers with spatial reference points, in the form of utilization distributions, which are heavily used by lake sturgeon within seasons. Future studies should examine what parameters are driving site selection in these areas.

Seasonal Movements and Spatial Overlap of Juvenile and Adult Lake Sturgeon in Lake Champlain

“…However, many studies do not have access to acoustic receivers outside of their focal study area. The development of large-scale telemetry networks makes it possible to examine large-scale fish movements even in large lake systems (Withers et al 2021) and could lead to more observations of long-range movements by juvenile Lake Sturgeon. Although the reasons for the winter movements we observed are unknown, the juveniles may have been investigating alternative overwinter sites.…”