Maine DIFW Reverses Course on Green Lake Arctic Charr
The Arctic Charr of Green Lake
Bob Mallard, NFC National Vice Chair
Located less than 20 miles from Acadia National Park and less than 15 miles from Bangor, the 3rd largest city in Maine behind Portland and Lewiston, Green Lake is a popular recreational fishing and boating destination.
For decades Green Lake was classified as a native Arctic charr water. At 3,132 acres, it was the largest of the 12 native charr waters left in the contiguous United States, and twice as large as the next biggest. From an acreage standpoint, it represented roughly 35% of the remaining native Arctic charr water.
Green Lake is also a native landlocked salmon lake, one of only four in Maine, and the only water where landlocked salmon and Arctic charr occurred naturally. Introduced landlocked salmon are said to have contributed to the demise of native Arctic charr populations in Rangeley, Maine. It is also a native smelt water, one of only two lakes in Maine where smelts and Arctic charr co-evolved. Introduced smelt are blamed for the recent collapse of native Arctic charr populations in Big Reed and Wadleigh Ponds.
As Arctic charr lakes in Maine, and by default the contiguous United States, go, to put it bluntly, Green Lake is a mess. Per Maine Department of Inland Fisheries and Wildlife (MDIFW), Green Lake has a “very low” abundance of Arctic charr, the only charr water so designated.
Green Lake is also home to roughly 20 species of fish, some of which are nonnative to the lake, including a few that are considered highly invasive to Arctic charr, most notably lake trout and smallmouth bass. It is also being actively stocked with landlocked salmon and lake trout, and is open to ice fishing and the use unrestricted bait, including live minnows.
Green Lake is also home to a federal fish hatchery, and has been the site of a hatchery since 1891, and this is where things start getting muddy. It is fairly certain that the hatchery at Green Lake raised Arctic charr, known at the time as golden trout, as in Sunapee golden trout.
It is also fairly certain that Green Lake and possibly a tributary were stocked with Arctic charr and/or Arctic charr eggs in the late 1800’s. Federal stocking records indicate that Green Lake and a tributary of the lake received Arctic charr eggs, fry,and adult fish from nearby Floods Pond in 1896, 1897, 1898, and 1899.
Note the references to stocking in the table located at the bottom center of the poster.
While unchallenged for decades, the presence of a hatchery on Green Lake that raised Arctic charr and records indicating that charr were stocked in the lake, led MDIFW to question whether the Arctic charr population was nonnative and the result of these plantings.
The first time I saw the status of the Green Lake Arctic charr listed as nonnative was in August 2018. It was in a table in a paper published by MDIFW entitled Bald Mountain Pond Conservation of Endemic Arctic Charr. The table identified the population as nonnative, and noted that is was the result of plantings of fish from Floods Pond.
Interestingly, the paper that challenged the status of the Green lake Arctic charr was about the problems faced by another native Arctic charr population, Bald Mountain Pond in Somerset County, that was collapsing under the weight of nonnative and highly invasive smelts and lake trout.
Not convinced that evidence of historic stocking was proof that the population of Arctic charr in Green Lake was nonnative, or even that the stocking events in question actually happened or resulted in any level of natural reproduction, I started researching the lake to see what I could find.
The first thing I found that challenged the position that the Arctic charr of Green Lake were nonnative was a paper written by Louis Bernatchez, a professor of genetics at Laval University in Canada in 2002. While well above my pay-grade and knowledge, the data presented indicated that Bernatchez recognized the fish in Green lake as a unique population.
Subsequent analysis by Dr. Michael Kinnison, an Arctic charr expert from the University of Maine in Orono, implied that not only were the Green Lake Arctic charr a unique population, they were more closely related to the charr from Wadleigh Pond than Floods Pond. This information was provided to MDIFW.
During a scheduled meeting between NFC and MDIFW in summer 2019, Maine NFC Chair Emily Bastian asked if the Bernatchez and Kinnison analysis and data had changed IFWs position in regard to the status of the Green Lake Arctic charr. They answered in the affirmative.
“It is our belief now that the Green Lake Arctic charr population is indigenous and did not originate from stocking. - Francis Brautigam, MDIFW”
So after a one-year sabbatical, Green Lake is once again classified as a native Arctic charr water.
Why does this matter?
With so few left, it is important that we know what is and is not a native Arctic charr population. This will help focus management efforts where they are needed most to ensure the long-term viability of the species. Each population is unique and needs to be protected.
A Good News/Bad New Story
The good news is that we once again have 12 not 11 native Arctic charr populations. That is an increase in waters of approximately 8%. It is also an increase in acreage of roughly 35%, and increases the total acreage to what is now roughly 8,900 acres versus just 5,766.
The bad news is that no Arctic charr have been confirmed in Green Lake since 2006, or 13 years. After a number of unsuccessful surveys using conventional traps, and one involving suspended minnow traps, the University of Maine is working on an eDNA survey that while it can not prove absence or abundance, it could prove presence.
What’s Next?
If we are unable to confirm the presence of Arctic charr in Green Lake, it could mean that the population has been lost. If we do, and it is at best remnant, it confirms that we should be doing more to save this unique population of rare fish.