Unless you are culturing or capturing copepods you will not be successful with Northern H. Erectus. They need pristine water quality! Any harmful bacteria and you can kiss them all goodbye, that's if they eat to begin with.
Taking 25 from the wild is doing a lot of damage. As you stated 1 out of a 1000 makes it. So by you catching and taking 25 this means 25,000 will have to be born to make up the seahorses you took.
If you are serious about breeding seahorse I may be able to help. I just got back from the Marine Breeders Initiative in MI. There was a very good presentation given by Dan Underwood of Seahorse source. George_g (Who you know) recorded the session. Maybe he can post? I'll talk to him or you can send him a PM.
Good Luck,
P.S. It's not against the law to take a couple but if they see you with 25 you will get a ticket for commercial use. Since the DEC is broke like every other agency don't think you will just get a warning.