2017 Sturgeon For Tomorrow Research

Lake Sturgeon Research and Stocking Summary

By Doug Larson, Research Technologist, Michigan State University

The 2017 Black Lake research season began on April 21st when Michigan State University (MSU) and Michigan Department of Natural Resources (MDNR) researchers captured six adult Lake Sturgeon ascending the Upper Black River. This was an early start compared to previous years, though the early captures did not appear to reach spawning ripeness before a string of cold weather pushed them out of the river.

A total of 233 adult Lake Sturgeon were captured during the spawning season, of which 33 were captured for the first time (14.16%). Sturgeon for Tomorrow member, Charlie Maltby, captured the first confirmed new-to-science fish who originated from the hatchery on May 17th. The largest single day capture was on April 27th, where t he crew sampled 41 fish. The largest fish captured this year was a 6-foot 4-inch female that weighed 151 pounds. Gametes were collected from spawning Lake Stur-geon and transported to the Streamside Rearing Facility for fertilization and rearing. In total 1,111 unique individual Lake Sturgeon have been cap-tured in the Upper Black River since 2001.

In addition to raising eggs in the hatchery, wild larval Lake Sturgeon were captured as they drifted downstream. Previous research con-ducted by MSU and MDNR found that wild larvae represent the highest quality genetic source stock, so MSU and MDNR make an effort to fulfill all stocking quotas with fish captured in the wild, where possible. This year, larval drift sampling began on May 17th and continued until the crew could no longer get into the river due to rain. we did a follow-up sampling on June 28th, finding that the larval drift period had ended. In total, researchers captured 19,135 wild dispersing larvae, the most cap-tured in a single season. In 2017, 549 Lake Sturgeon were released into the Black River. All fish that were stocked into the Black River were implanted with a passive integrated transponder tag, which will aid future management efforts. In addition, 549 Lake Sturgeon were released into Mullett Lake, all of which were implanted with a coded wire tag. The Sturgeon released into Black River and Mullet Lake reached an average length of over 7 inches. Increased size at stock out can be attributed to an improved feeding strategy developed and published by John Bauman. Research efforts in 2016 focused on factors contributing to reproductive success; par-ticularly those that can be quantified by data collected from Radio Frequency Identifica-tion (RFID) antennas placed throughout the Upper Black River. In addition, researchers continue to investigate the downstream passage of juvenile Lake Sturgeon through hy-droelectric facilities. The research crew also began a pilot investigation into the down-stream collection of wild-captured juvenile lake sturgeon. Smaller projects included measuring the effect of aquatic macroinvertebrates on Lake Sturgeon eggs and free em-bryos; predation of lake sturgeon eggs and free embryos by Rainbow Darter (Etheostoma caeruleum, Storer, 1845); the selective properties of female lake sturgeon ovarian fluid; and the effect of biotic and abiotic factors on the quality of male Lake Sturgeon sperm.