The weekend of August 27th, 2005 was quite an eventful one on East Stoner Lake. At first there were casual reports of people seeing Freshwater Jellyfish in the lake and many people didn't believe it, me being one of them. However, on Saturday afternoon it became evident that there were indeed jellyfish in the lake. In fact, there were thousands off them. They are small, about the size of a quarter, and are almost transparent, but they could easily be seen in calm water, suspended about two feet below the surface. Larry Smith held one in his hand and he wasn't stung, and we were skiing and swimming all day with no ill effects. I have contacted the State and it doesn't appear that this is very uncommon. I have done some internet research and it appears these visitors are called Craspedacusta sowerbii. There is an entire website devoted to this topic, so check it out (http://www.jellyfish.iup.edu). In fact, there are many lakes in the Adirondacks that have experienced such a phenomenon, including Caroga Lake.
In many instances, these jellyfish will be seen in a lake one year, and never again, or in intervals of several years apart. In fact, some of these jellyfish can survive the winter so it is possible we will see them again next year. I've only just started my research in this department, so I'll add more when I learn more! Below is a picture of one of these jellyfish courtesy of Bill Davis and an article I found in Adirondack Life.