For those who are interested in the American Eel:
Yes they live in Winnipesaukee as well as most lakes. The record Eel for New Hampshire was caught in Crystal Lake in July of 1975 by Mr. Michael Hasharak and it was 44.5" and weighed 8 Lbs.
The Eel all originate in the Salt Water and migrate from as far away as the Sargasso's and this takes a long time. They migrate up rivers through brackish waters into fresh waters. They end up spending their maturing years in fresh water lakes, ponds, rivers and move back to the sea when the maturity bell rings and sends them on their mission to propagate.
For a very long read, I have listed a link to the U.S. Department of Interior, Fish & Wildlife Service report about the life cycle of the American Eel.
John/NH
http://www.nwrc.usgs.gov/wdb/pub/1047.pdf