“‘Thus otters serve as biomonitors – organisms that contain information on the quantitative and qualitative aspects of the environment – of wildlife exposure,’ according to a new study. They also serve as biomonitors for human health because the same toxic chemicals found in otters have also been found in people who eat contaminated fish.The study published in the journal ‘Ecotoxicology and Environmental Safety’ found high concentrations of chemical compounds in the livers of 23 otters in central Illinois.Especially troubling were the highest concentrations of dieldrin ever reported in otters anywhere in the United States, said lead author Samantha Carpenter, a wildlife technical assistant at the University of Illinois, Urbana-Champaign.Dieldrin is one of the organochlorine insecticides banned in 1978. More than three decades later, high levels of the chemicals remain in river sediments and accumulate in the fish that otters and people may eat.The compound has been linked to neurological, behavioral and immune-suppression problems in wildlife. Scientific studies disagree on adverse human effects, but some studies have linked dieldrin to asthma, Parkinson’s disease, Alzheimer’s disease and breast cancer, Carpenter said.”
Recent News
- Freshwater jellyfish may increase in numbers as Illinois and Indiana waters continue to warm
- Tomas Höök signing off as Illinois-Indiana Sea Grant director this summer
- Illinois-Indiana Sea Grant welcomes Stuart Carlton as the program’s new director
- Four Illinois and Indiana educators will set sail on Lake Michigan aboard EPA’s research ship
- Join IISG as a new pollution prevention outreach assistant
IISG Instagram
🌊 Making Waves in Education
Calling all K–12 educators — formal and non-formal! Stay connected to the Great Lakes and inspired in your teaching with our educator-focused newsletter.
📬 Why Subscribe?
✅ Discover teaching resources and professional development opportunities
✅ Connect with Sea Grant partners and community efforts
✅ Bring Great Lakes science and stewardship into your classroom or program
🗓️ Published quarterly — with occasional bonus issues when exciting events or new content arise!
💡 Whether you’re in a classroom, nature center, or museum, this newsletter helps you make waves in education.
👉 Sign up now: https://iiseagrant.org/education/subscribe-to-education-newsletter/
#TeachingTuesday
#GreatLakesEducation

Looking for a fun, hands-on way to engage your students this year? Check out our new curriculum about crayfish and freshwater ecosystems! This curriculum teaches students about the importance of native crayfish, the threats posted by invasive species, and the health of Great Lakes ecosystems. It includes 9 ready-to-use lesson plans, with one featuring our participatory science activity! All lessons are aligned with NGSS, CCSS, and CGLL Principles.
Download the curriculum and start exploring at InvasiveCrayfish.org/Crayfish-Curriculum
#CrayWeek #Crayfish #FreshwaterEcosystems #Curriculum #BackToSchool

When participating in a crayfish participatory science activity, be sure to snap plenty of photos of any crayfish you catch or observe. Not only is it a great way to capture the fun and excitement of the day, but it also helps document the species present. To ensure accurate identification by scientists, it’s important to provide clear photos from multiple angles. Dorsal (top), lateral (side), and ventral (underside) views of the crayfish should always be photographed.
To learn more about the specific features to highlight in your photos visit the link in bio or
InvasiveCrayfish.org/Management/#Community

Who says “Back to School” means back indoors? While the weather is still warm, take your students on an outdoor science adventure by exploring crayfish in your local waterways.
The Invasive Crayfish Collaborative invites grades 2-12 educators to take part in a hands-on participatory science activity. By catching, identifying, and reporting crayfish species in your area, students contribute valuable data that helps scientists better understand where native and invasive crayfish live.
Check out what other educators have found and get involved: inaturalist.org/projects/great-lakes-crayfish
