I just completed my BSc in marine biology (took aquaculture paper) and will be heading back to uni to complete my pgdipsci and masters next year at the University of Auckland.
As mentioned above there is a course at BoP polytechnic and one at Mahurangi, although they are not degrees in a classic sense you can get good practical skills at these institutes.
At the end of last year I did a volunteer stint at the NIWA aquaculture facility in Ruakaka, they offered me a job for the period between my studies and I really like it. We do research on Hapuka, Kingfish, Salmon atm, but occasionally other stuff. My end goal would be to get into commercial aquaculture.
Yep, I support the industry. For a planet that needs food and has declining fish stocks aquaculture offers an amazing environmentally friendly (group and situation dependent) option. Sure there are problems like any industry, (using wild food fish to create feed/parasites etc) but when compared to alternative farming it can have minimal env impacts with proper management. In regards to Salmon; most of the problems are N.H based, NZ production of salmon is so isolated that our industry is not under the same pressures compared to atlantic/nordic zones. Can't really speak for disease on mussels and oysters, but any outbreaks are spatially restricted it would seem, NZ mussel is regarded as the best in the world (220 million p.a).
There are barely any jobs available in ornamental fish aquaculture and would be hard to crack that business. NZ employment is relatively limited, but given time we could have an industry (in my opinion) that could rival dairy.
I will probably look overseas for work, but would love to be based in nz.
If you're interested in the science behind it you would need to go through to masters level probably. People in NIWA all have high level qualifications.
Hope this helps!