Aquaculture interests me far more than working with cattle, sheep or horses. Having had aquariums as a kid sparked my interest and gave me a basic understanding of aeration and filtration and the importance of water quality.
The initial readings I undertook proved extremely positive. Per metre square, aquaculture can sustainably produce more protein than other land based farming. You've got me sold! The way that you can tie in fertilization of a crop from the waste water is another appealing benefit, creating a more sustainable system and aquaculture ties in very closely with the principles of permaculture. In that respect I think that ideally all aquaculture farming should include a degree of land based farming, even producing a crop that can be used as fish feed.
Because the large scale intensive production methods are still relatively new and research into the habits of the animals is not as comprehensive as the research carried out on land based animals it may not be as attractive as a new enterprise, however this could also be seen as a positive in that there are still many avenues left unexplored, allowing a farmer to set themselves apart and develop a niche market. There is greater potential for failure and loss of stock, however with time and practice, aquaculture should be able to be extremely profitable and on top of this any advancements made could help starving populations of the world and the environment by allowing overfished oceans to restock.