A friend asked me about sustainable seafood and I promised some information
Here is the quick guide I promised
The link to the seafood guide is
http://www.sustainableseafood.org.au/Sustainable-Seafood-Guide-Australia.asp?active_page_id=695
and it is downloadable from the app store
There is also the ACF Sustainable Seafood campaign information http://www.acfonline.org.au/be-informed/oceans-rivers/sustainable-australian-seafood. There is a cool and neat interactive map.
Greenpeace Australia is also in on the action with http://www.greenpeace.org/australia/en/what-we-do/oceans/Take-action/The-Seafood-Redlist/
And there is an excellent pdf for download there
A couple of general comments follow. With fish it is more sustainable if they are farmed in tanks on landed than in pens at sea. The drawbacks of pen raising are they are fed fish humans can eat, they are pumped full of antibiotics as the concentration of fish makes them susceptible to disease, they poop the antibiotics out into the environment and they poop. There is a very high concentration of fish poop beneath the pens which destroys the the environment beneath the pens. And some of the non-native fish escape into native waters. That said I understand Tassie pens are better than some.
As a rule smaller fish are better to eat than bigger - that is better 'for the environment'. The better fisheries are certified by the Marine Stewardship Council.
Generally wild caught fish are better for the person eating them than farmed as wild caught fish have a more diverse diet and are not pumped full of antibiotics.
So there is an app, an interactive map and pdf. Good coverage.