The crucial difference in Kalk-logic where it pertains to seahorses, IMO is the destruction factor.
To my knowledge, with the possible exception of seahorses collected in trawl nets as a bycatch of shrimp or other food harvests, seahorse collection is not devastating to the reef. In fact, seahorses don't live on the reef, they live in turtle-grass beds. I don't know of anybody that couldn't catch one with their bare hands, so cyanide is not an issue, nor is crowbars, blasting or other implements of destruction.
IMO the main cause of the depletion of wild seahorse populations IS the TCM trade, perhaps followed by the curio trade. Can't tell you how many dead dried seahorses I've seen in a lifetime, in seaside shops, along with conch shells and sand dollars... I'm guessing that many of those are a bycatch too, but I don't know for sure.
I'm not suggesting that the hobby has no impact but depending on whose study you read, the real impact of the aquarium hobby on wild stocks is much smaller than the proportion of TCM/curios. Compared to the cyanide food fishing versus cyanide MO fishing, it's like comparing apples to bowling balls.
I'm not trying to justify - just put it into perspective.
I do think the hobby has done good things for the seahorse - lots of people including myself, have had seahorses reproduce - in my case rearing the fry was a failure at best - I got one to 6 months despite a pair that had fry every 14 days like clockwork. Many hobbyists are having better success than I did - and we're learning a lot about the animals themselves - which certainly translates to good for the genus somewhere down the line.
They aren't for "every hobbyist" but they are certainly appropriate for those who can set up an appropriate habitat for them, and are willing to give them appropriate care.
JMHO
Jenn
