They've looked at the genes of these different groups and have determined that they're sufficiently different genetically to constitute different species.
Now, that does not mean that there is any meaningful difference in the traits or the ecology of these species. No one has looked to see if there are differences in the life history of these species, in their pathogenicity, in their host specificity, and so on. In general, they have the same life history, the same life cycle, and similar sensitivities to temperature and salinity.
I think there's a lot we've learned from the Atlantic form that is transferrable to the Pacific; we just have to be cautious about how we do that.