How often do fish eat in the winter ponds and lakes in Massachusetts?

It depends on the size and the type of fish. If the fish are koi, they probably won't bother them. If they are smaller fish they most likely will eat them.

You can but I wouldn't. I have one in my neighbors backyard which they let me fish in. All the pesticides and manure they out on their lawn eventually goes into the retention pond. And some of them...

Yes, ss long as the water is not polluted and the fish are healthy. Many commercial fish are lake fish - like smelt and walleye.

algae, worms, other fish

Some eat smaller fish, insect larvae, bits of algae and plant life plus they should be fed whatever specialised diet the species requires by whoever looks after the pond.