Microcystin Data

Weekly microcystin toxin report

Summer 2025 Results

If you already signed up for our microcystin toxin update emails, thank you! We’ll send reports to your inbox May-August. If you haven’t, what are you waiting for? They will remind you to check this page to see which lakes have microcystin detected, and at what levels.

Supported by the K21 Health Foundation, we sample 16 lakes and seven public beaches every week from June-August, and 14 streams biweekly year-round. Visit these excellent and educational resources to learn more about blue-green algae:

WEEK 9 RESULTS: JULY 18

IDEM’s safety threshold is 8.0 ppb for humans and 0.8 ppb for pets.

ND – None Detected

– – –  Data unavailable for this sampling week 

LakesConcentration (ppb)
Beaver Dam Lake0.335
Yellow Creek Lake0.584
Silver Lake3.657
Winona LakeND
Center LakeND
Pike Lake0.236
Big Chapman Lake0.401
Big Barbee Lake0.777
Webster Lake0.429
Lake TippecanoeND
James LakeND
Oswego LakeND
Dewart Lake0.3
Waubee Lake3.194
Lake Wawasee*0.661
Syracuse LakeND

*See spatial variability results below.

BeachConcentration (ppb)
Center Lake Beach0.177
Pike Lake Beach0.403
Syracuse Lake Beach - Community Center0.306
Syracuse Lake Beach - Hoy0.255
Waubee Lake Beach4.929
Webster Lake Beach0.285
Winona Lake Beach0.291

Additional sampling on Lake Wawasee

Thanks to the support of two generous Lake Wawasee families, the Lilly Center samples seven additional sites on Lake Wawasee during the summer of 2024. All water samples from these sites were tested for microcystin.

IDEM’s safety threshold is 8.0 ppb for humans and 0.8 ppb for pets.

ND – None Detected

– – –  Data unavailable for this sampling week

LetterNameConcentration
ADeepest Point0.661
BNorth Shore0.521
CConklin Bay0.515
DSouth Shore0.711
ESandbar1.656
FJohnson Bay1.383
GJarrett's Bay1.884
HCrow Bay2.26

What's next?

Every October, we publish Beneath the Surface, a report on our summer research as compared to the two previous years.

The 2024 edition includes a spread dedicated to blue-green algae (and microcystin) analysis! If you’re curious about what we learned over the course of the summer, make sure to grab a digital copy.

Why & how the Lilly Center samples for microcystin

From June-August, the Lilly Center collects water samples from open water on Kosciusko County’s 12 all-sport lakes and Center, Pike, Waubee, and Silver lakes, along with public swimming beaches at these lakes:

  • Center
  • Pike
  • Syracuse
  • Waubee
  • Webster
  • Winona

Samples are processed and analyzed for microcystin, a toxin produced by blue-green algae. If ingested or left on the skin for too long, microcystin can cause health problems for people and pets. It’s especially dangerous for animals, like dogs.

Toxin results are updated on this page every week during the summer. To learn more about microcystin and pet and human health, visit our blue-green algae research hub!

As a general guideline, don’t recreate in water that has a blue-green algae bloom! Blooms often look like a green paint slick on the surface or a pea-soup appearance. If you see a bloom (or aren’t sure if it’s a bloom) email us the date, time, location and a picture and a team member will follow up with you.

Collaboration with IDEM

Lilly Center algae sampling and analysis are coordinated with the Indiana Department of Environmental Management (IDEM) to ensure statewide data comparison and accuracy.

Visit IDEM's website