can u sell them fish freshly caught?

I don't see them doing that unless you're a licensed fisherman with a good business reputation...

No, it wouldn't be in keeping with their reputation.

Probably not

must be a licensed fisherman with a good reputation.

I would say No

I don't think they buy fish unless your a licensed business. They may offer to cook your fish for your own consumption.

Probably only if one is a professional fisherman with established reputation.