Various partners of the Michigan Arctic Grayling Initiative gathered in Manistee on October 8, 2019 for an annual meeting. Presentations were given on work conducted on behalf of the initiative over the past year. Those in attendance heard about the following:
Fish production efforts
The past year has been eventful from the fish production perspective, with several milestones being reached. Multiple DNR, Fisheries Division staff flew to Alaska to assist with the Arctic grayling egg take. In order to start Michigan’s broodstock with as genetically fit parentage as possible, the Alaska Department of Fish and Game graciously agreed to significantly expand their normal egg collection procedures. The extra hands from DNR were necessary to make that happen.
The final funding for the ultraviolet unit installation at Oden State Fish Hatchery’s isolated rearing building was received just in time for the first year of future brood fish to be established in 2019. Construction was completed just prior to when the fish needed to be transferred from the Michigan State University containment facility. The Oden crew had a short window to work out any kinks in the system, but they pulled it off. The fish were successfully transferred to Oden in early August (see next paragraph for more detail).
Arctic grayling quarantine
As stated previously, the completed UV system at Oden’s Isolation Building ensures all the water leaving that system is disinfected. This ensures any possible disease the grayling may harbor will be contained and will not be able to spread into the waters of Michigan. On August 1, the DNR transferred 3,751 from MSU’s containment laboratory, which had been reared by Nicole Watson in conjunction to her grayling studies. The fish are growing quickly, are healthy, and are very active. The first of three required fish health tests, which must be spread six months apart, was completed just prior to this transfer and did not find any diseases of concern. The fish will be reared in Oden’s Isolation Building until results of the final health exam are complete. If no diseases of concern are found, they will be transferred to Marquette State Fish Hatchery, approximately in late September of 2020.
Focus on management
An update was given on stream nominations to consider for future Arctic grayling introduction or stocking. The public has nominated 32 streams to date. The Upper Manistee, Maple, Boardman and Upper Jordan rivers are the top candidates currently. Partners are seeking funding and assistance to gather fish community and habitat information on these top candidate streams. Reid, Hoist and Penegor lakes were also nominated to receive any surplus broodstock or production Arctic grayling in the future. These lakes would be open to the public and would provide another fishing opportunity for these amazing fish. Nominations for both streams and lakes can continue to be made to the partnership.
Research on juvenile fish
The overarching goal of Nicole Watson’s Ph.D. research is to clarify key uncertainties to successful reintroduction of Arctic grayling to Michigan streams. There are three core unknowns that she is focused on: imprinting, predation by young resident trout, and competition between resident trout of the same year-class. Examination of these three core components has led to additional work including: water choice trials, a component of imprinting; retinal and olfactory development; predator avoidance; alarm and predator cue recognition; and habitat and behavior interactions. In May 2019, 10,000 grayling eggs were transported from Fairbanks, Alaska to East Lansing. Of those, 3,759 fish were transferred to Oden State Fish Hatchery in early August to establish Michigan’s first year class of brood stock. Research is ongoing in the lab with results consistent with last year’s trials: growth of grayling may not be limited by the presence of brook trout, but there is a high level of competition between grayling and brown trout. Further, brown trout prey more heavily on grayling fry than do brook trout.