Overseas information on the economics of extensive aquaculture.
Two forms of specialist aquaculture exist in NZ, Artemia and Algae for biofuel production. Pilot scale production has been achieved in both of these.
Artemia (brine shrimp) can be farmed for live feed to the aquaculture industry. Extremely high quality Artemia has been cultivated at Lake Grassmere (in commercial salt production ponds near Blenheim). Production was small and supply erratic but such ventures have some potential.
Micro algae can be farmed for biofuel production. This generally works best in warm climates without seasonal temperature and sunlight fluctuations,however there is some potential for NZ.