Please don't release him into the local waters. Even if his species is plentiful around there, many of the things you keep him with are not. For that reason, it is never a good idea to reintroduce an animal that has been kept in a tank to the wild, even into same waters it was collected from. No one that causes damage by doing things like this ever thinks it will be a problem, nor do they intend for it to, but it happens. It happens in ways that can be difficult to predict beforehand, and even more difficult to fix. If you do it, will it cause any harm? Probably not, but why would you risk it?
That aside, If he came in on material from a tropical area, its not certain he'd survive in Jersey temp waters. Being the same species as those that live in a given area doesn't imply that he'd survive in those conditions. My understanding is that where they "grew up" also has an effect on their tolerances.