Well theres the East River or the Hudson, and though the parks now have a NO KILL policy in place, I believe that is only on Fish, though I could be wrong. There are Tons of Red Crawfish/Fresh water Lobsters in a lot of the Cities Park Lakes. Plus Billions of small Black Snails, which when I use to keep Loaches, would relish them. Depending on what your feeding the City Parks can be a GREAT source for finding Worms, both Red Wigglers & Night Crawlers, also Grubs and Beetles (My RTGG and other tank buddies love Spring through Fall, I flip over a few leafs in leaf pile & 50-70 Worms come home). In Spring time and early Summer one can catch all sorts of Insect Larve like Dragonflies. That I can attest that the NO KILL policy doesn't cover. And if you know where too look just outside the City limits you can find a nice supply of Leeches too boot.