I do know that bowfishing in freshwater for "rough fish" is legal. "Rough fish" includes carp, suckers, and shad, and I'm sure some other species. But carp and shad are the most common targets for bowfisherman.
I used to really enjoy bowfishing for shad during the spring run. I used to have a "stand" in the Delaware right at the head of the island near Old King Cole's a little bit north of Belvidere. The floods several years ago washed it away, and I never bothered building another one.
I had a 12 volt battery with a spotlight rigged up to it that I would float out there in an inner tube to spotlight for the shad after dark. I would wade out to my stand with a friend about 2 hours before dark. Once it got dark we would take turns working the light. We would usually take our limits (6) without much trouble. Of course the run only lasted a couple of weeks.
It was a ton of fun, but it could be dangerous crossing back in the dark, as the channel we had to cross was deep with a strong current. A guy much shorter than me (as you know I'm about 6' tall) would be over the top of his chest waders.
You could also try bowfishing for carp. There's plenty of how-to info out there on the web. One of the best lakes I know of is Spruce Run Reservoir. There are some shallow, muddy flats across the lake from the boat launch where I've seen plenty of carp. I just never bothered bowfishing for them.
Here's what the regulations say about freshwater bowfishing:
Bow and Arrow Fishing
Any species of fish, except brook, brown, lake
or rainbow trout, landlocked Atlantic salmon,
largemouth or smallmouth bass, striped bass
or any of its hybrids, pickerel, northern pike,
walleye, muskellunge or any of its hybrids, may
be taken at any time by use of a bow and arrow
with line attached by the holder of a valid fishing
license. See regulations for the Delaware
River and Greenwood Lake, page 24–25.