2017-07-13 / Front Page

Swimmer’s itch snail infection levels down, according to report

“Progress is being made,” in the fight against swimmer’s itch in Gerrish Township, according to resident Ken Dennings, former president of the Hig­gins Lake Swimmer’s Itch Organization (HLSIO).

Dennings spoke to the Gerrish Town­ship Board at its regular meeting Tues­day as a private citizen, explaining he stepped down from the HLSIO (as well as the Higgins Lake Property Owners Association), due to medical reasons. He presented an interim report from Dr. Curt Blankespoor of Swimmer’s Itch So­lutions – formerly SICon –summarizing recent activity.

Dennings said 55 common mergan­ser ducklings have been removed from Higgins Lake, relocated and were web- tagged. He announced that biologists tested more than 4,100 snails and did not find any infected snails. (The swim­mer’s itch life cycle includes both ducks and certain snails.) He said that does not mean there is no swimmer’s itch in the lake – there was a recent report on the Lyon Township side of Higgins Lake.

Dennings distributed copies of Blankespoor’s report to the board.

According to Swimmer’s Itch Solu­tions, Higgins Lake had a 2.6% snail infection level as July 2, 2015, (3,604 snails collected) and on June 29, 2016, the lake had a snail infection level of .25% (5,897 snails collected). Through June 28 of this year, 4,120 snails were collected and no swimmer’s itch para­sites were found.

Dr. Blankespoor told the Resorter Wednesday that another 1,000 snails were collected Tuesday and one snail was infected, for a resulting .02% infec­tion level (1 in 5,000.) He said another 1,000 would be collected Wednesday, the third batch of 2,000 snails inspected this summer.

“Please understand that we are not claiming that swimmer’s itch is gone from Higgins Lake this year,” Blanke­spoor said in the summary report. “What these data are telling us is that there are even fewer infected snails compared to last year at this time in the summer. That’s very encouraging and exciting news!”

As of June 28, there were four broods trapped and relocated (including two from unsealed nest boxes on Treasure Island).

Working with Dr. Blankespoor have been Dr. Dave Jude (University of Michigan), Dr. Randy DeJong (Calvin College) and Dr. Ren Tubergen (Calvin College). The team used two new re­search tools, a borescope camera (on a pole) and a drone, piloted by Ric Blamer. They found several possible nesting sites on Treasure Island.

“While we didn’t find any evidence (e.g., eggs or feathers) to suggest the cavities were being used this year, it is quite possible, since common mergan­sers are nest prospectors, they will be used in the future,” Blankespoor said in the report. “We have the GPS locations of each cavity and are willing to assist landowners in plugging those holes.”

He reported that two common mer­ganser eggs were found in the spring, “both in very unusal places,” one in six inches of water west of Stoney Point and one on the ground at the base of a tree on the west side of Treasure Island.

The full summary report is available at the township hall.

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