cold water question

[asylumdown]

If you design for a deeper water cool system as opposed to a shallow system like a kelp forest or tidal zone, where will you get livestock? You don't hear about species from cold water zones being brought up in to the hobby trade all that often. I imagine as a local free diver it would be easy to collect relatively shallower organisms, but the only deep cold water organisms I've heard about being brought to the surface are usually on that night's sushi menu...