Keeping Tabs on the Next Generation of Lake Erie Lake Sturgeon
BY ANDREW BRIGGS, ALPENA FWCO-WATERFORD MI SUBSTATION
Lake sturgeon are a long lived fish species that can reach enormous lengths. They have been found to live over 100 years and reach lengths greater than seven feet. However, lake sturgeon are an endangered or threatened species in much of their range, including the Great Lakes. In Lake Erie, they are thought to be extirpated from much of their historic habitats and spawning areas. Remaining spawning populations are known to exist in the Detroit and Niagara Rivers and numerous lake sturgeon sightings have been made throughout Lake Erie.
In order to learn more about the remaining lake sturgeon populations in Lake Erie, a Juvenile Lake Sturgeon Index Survey for Lake Erie is being implemented. This survey is part of the binational Coordinated Science Monitoring Initiative where federal, state, and provincial agencies collaborate to conduct a lake-wide lake sturgeon assessment. Similar to the lake-wide juvenile lake sturgeon assessment conducted in Lake Superior, the objectives of this survey are to describe the current status of juvenile lake sturgeon in Lake Erie, create a means of estimating recruitment, year class strength, and population trends over time, and to describe and compare the biological characteristics of juveniles within and among locations throughout Lake Erie and over time. To meet these objectives, personnel from several U.S. Fish and Wildlife Service (Service) offices, Michigan Department of Natural Resources, Ontario Ministry of Natural Resources, Ohio Department of Natural Resources, New York State Department of Environment and Conservation, and Pennsylvania Fish and Boat Commission set gill nets targeting juvenile lake sturgeon at the mouths of thirteen known historic lake sturgeon spawning tributaries.
Fish biologists from the Alpena Fish and Wildlife Conservation Office – Waterford, Michigan Substation conducted assessments near the Sandusky and Maumee Rivers in Ohio, and near the mouth of the Detroit River in Michigan and Ontario waters. Gill nets with varying mesh sizes were used to target juvenile lake sturgeon. In addition to gill nets, water quality and substrate information was collected at each net location. No lake sturgeon were captured near the Sandusky, Maumee, and Detroit Rivers this fall; however, seven were captured during the summer of 2013 at the mouth of the Detroit River using the same technique. Species commonly caught included channel catfish, common carp, freshwater drum, gizzard shad, and walleye.
St. Clair-Detroit River System. Credit: Justin Chiotti, USFWS
Although few lake sturgeon have been captured during these assessments, they are important for comparing future catches as lake sturgeon restoration efforts continue in Lake Erie and the other Great Lakes. Hopefully as restoration efforts continue, lake sturgeon catch rates will increase. Additionally, these assessments offer the opportunity for the Service to build and maintain partnerships; collaborating with partners to conduct a lake-wide assessment of juvenile lake sturgeon would not be achieved without the dedication of multiple agencies.