Cayuga Lake has struggled with harmful algal blooms or HABs in recent years, but in 2021 unseasonably warm temperatures and heavy rainfall may have extended their prevalence late into the year.
Significantly more harmful algal blooms were reported on Cayuga Lake this year than in 2017. A local non-profit reports the 2018 blooms were more likely to contain toxins harmful humans and small mammals, like cats and dogs.