NOTICE: THE BLPS SWIMMER'S ITCH PROGRAM IS ON HOLD DUE TO RESTRICTIONS ON BIRD LOCATION DURING AVIAN FLU. THE INFORMATION BELOW IS AN HISTORICAL ARCHIVE OF THE PROGRAM.
Results From The 2021 Season
Our partner, Swimmer's Itch Solutions, told us that after two seasons we should see a dramatic change in swimmer's itch cases on Black Lake. Well, they were right about that! BLPS members reported 17 merganser sightings on Eyes on The Lake that alerted SI Solutions automatically. They responded by trapping 5 broods including all 31 ducklings and relocated them to locations that don't have the snail that completes the lifecycle of the parasite that causes swimmers itch.
Tests of lake water, bird fecal matter, and snails reports that the relocation of the common mergansers has resulted in substantial decrease in the swimmers itch parasite. The parasite was detected in only 2 of 7 testing sites (vs 5 of 7 in 2019). These results were substantiated with chance encounters with property owners that reported a very noticeable change in their experience with Swimmer's Itch was greatly improved. 19 cases of Swimmer's Itch were reported on Eyes on the Lake in 2021. We don't have a baseline comparison for that measure, but will have it for 2022. Remember that the actions that we take in 2021 will affect our measures in 2022, so we are optimistic for improvement this year..
Unfortunately, a new species that uses mallard ducks as the host was detected. This species has never been detected in northern Michigan lakes before. We'll be attentive to this issue in 2022.
As we’ve made clear in the past, it’s impossible to completely eradicate swimmer’s itch on any lake. The verified presence of avian schistosomatid C and T. szidati means that these parasite species are also cycling on Black Lake, and likely contributing, albeit to a much lesser extent than T. stagnicolae, to swimmer’s itch cases on Black Lake. Recent evidence we have conducted this year further supports this conclusion.
We continue to believe that the frequency and severity of swimmer’s itch cases will continue to decrease as the T. stagnicolae levels in Black Lake decrease.
Tests of lake water, bird fecal matter, and snails reports that the relocation of the common mergansers has resulted in substantial decrease in the swimmers itch parasite. The parasite was detected in only 2 of 7 testing sites (vs 5 of 7 in 2019). These results were substantiated with chance encounters with property owners that reported a very noticeable change in their experience with Swimmer's Itch was greatly improved. 19 cases of Swimmer's Itch were reported on Eyes on the Lake in 2021. We don't have a baseline comparison for that measure, but will have it for 2022. Remember that the actions that we take in 2021 will affect our measures in 2022, so we are optimistic for improvement this year..
Unfortunately, a new species that uses mallard ducks as the host was detected. This species has never been detected in northern Michigan lakes before. We'll be attentive to this issue in 2022.
As we’ve made clear in the past, it’s impossible to completely eradicate swimmer’s itch on any lake. The verified presence of avian schistosomatid C and T. szidati means that these parasite species are also cycling on Black Lake, and likely contributing, albeit to a much lesser extent than T. stagnicolae, to swimmer’s itch cases on Black Lake. Recent evidence we have conducted this year further supports this conclusion.
We continue to believe that the frequency and severity of swimmer’s itch cases will continue to decrease as the T. stagnicolae levels in Black Lake decrease.
Your browser does not support viewing this document. Click here to download the document.
Learn to Reliably Identify a Common Merganser Brood by Clicking HERE.
Preventing, Diagnosing, and Treating Swimmer's Itch
Swimmer's Itch has risen high among the priorities of the users of Black Lake in recent years. Swimmer's itch is a rash usually caused by an allergic reaction to parasites that burrow into your skin while you're swimming or wading in warm water. The parasites that cause swimmer's itch come from various combinations of snails and waterfowl. In Black Lake, most of the parasites come from the Common Merganser. Humans aren't suitable hosts, so the parasites soon die while still in your skin. Swimmer's itch is uncomfortable, but it usually clears up on its own in a few days. In the meantime, you can control itching with over-the-counter or prescription medications.
The itchy rash associated with swimmer's itch looks like reddish pimples or blisters. It may appear within minutes or days after swimming or wading in infested water. Swimmer's itch usually affects only exposed skin — skin not covered by swimsuits, wet suits or waders. Signs and symptoms of swimmer's itch typically worsen with each exposure to the parasites. Talk to your doctor if you have a rash after swimming that lasts more than three days. If you notice pus at the rash site, consult your doctor. You might be referred to a doctor who specializes in skin conditions (dermatologist). Swimmer's itch isn't contagious from person to person, so you don't need to worry about catching swimmer's itch from someone who has this itchy rash. Children may have the highest risk, since they tend to play in shallow water and are less likely to dry off with a towel. Some people are more sensitive to swimmer's itch than others are. And, your sensitivity can increase each time you're exposed to the parasites that cause swimmer's itch. To reduce the risk of swimmer's itch:
|
Our partner, Swimmer's Itch Solutions has some very good introductory information about Swimmer's Itch, and you can find it by clicking HERE
There's also a 3 minute explanation in the video to the right. |
Black Lake Swimmers Itch Assessment
The following report explains what our partner, SI Solutions found regarding Swimmer's Itch in Black Lake
Your browser does not support viewing this document. Click here to download the document.

blacklakeassessmentfinalreport2019.pdf | |
File Size: | 1594 kb |
File Type: |
Notify Our Partner, SI Solutions, and other BLPS Members Know of Your Observation
If you know of a case of Swimmer's Itch, please enter it into the EYES ON THE LAKE data collection web app by clicking on the button below. Filling out the form that comes up will add your finding to our Geospatial Information System (GIS) so it can be seen by SI Solutions and BLPS members using our EYES ON THE LAKE app. This information helps to detect patterns regarding where the parasite congregates. This information is useful to our partner, SI Solutions and to users of the lake in the areas of greater concentration.
You may also choose to report your findings and your Spotter activities on our Facebook page found HERE. |
Consider Helping With The Cost to Trap and Relocate
Each brood that we trap and relocate eases the swimmer's itch problem on Black Lake, but each brood relocation costs about $3,000. Please consider contributed to our fund to trap and relocate by clickintg HERE or going to the Donations page in the menu. Once at the Donate page, choose Swimmer's Itch to make your donation. All lake users thank you for that!!