Lake Sturgeon Movements after Passage Upstream of Two Hydroelectric Dams on the Menominee River, Wisconsin-Michigan

Lake sturgeon (Acipenser fulvescens) recovery in the Great Lakes is thought to be hindered by the presence of dams on Great Lakes tributaries. Dams deny these fish access to riverine habitat needed for spawning and survival during early life stages. We will attempt to mitigate this effect on the Menominee River by passing 120 mature lake sturgeon upstream of the first two hydroelectric dams over a two year period. Our objectives are to determine if: 1) lake sturgeon passed upstream return downstream within 1 or 2 years; 2) lake sturgeon have the opportunity to spawn at least once upriver; 3) spawning opportunity and downstream return rates are related to biotic and abiotic variables; and 4) the number, length, sex, and timing of passage can be manipulated to maximize the number of eggs deposited upriver. Each lake sturgeon passed will be surgically fitted with a VEMCO^® V16 acoustic transmitter and their movements monitored with an array of VR2W receivers and a VR100 portable receiver. A total of 60 of the 120 lake sturgeon have been passed upstream to date. Preliminary results indicate most lake sturgeon return downstream within 1 year, however, number of spawning opportunities and individual movement patterns are variable.