Speaking of... an 18" carp did start rooting in the weeds below us. He made quite a commotion. I wondered if there were any bass. Usually if there are sunfish, there are also bass, often in some very tiny, skeegy ponds. I did finally see one small bass. Then a duck flew in, swam around, and climbed ashore.
Today my husband and I were nearby at Riverview Park checking out some recent trail work when he mentioned he saw kids fishing in the canal the other day. I peered over the concrete wall, and sure enough, there were lots of good-sized sunfish for the kids to catch. (Note this is NOT a place to take the kids fishing - there are train tracks alongside the back of the canal).
And then I saw the circular sunfish nests along the bottom of the canal. Lots of them. Sunfish don't need as much oxygen as trout, but they are more sensitive than carp (I've accidentally killed pet sunfish more than once while the goldfish in the same water were fine).