If you want to eat fish, sardines and anchovies are more sustainable than any other species. While stocks may vary from region to region (eg:Peruvian anchovy stocks collapsed in 1970s due to over fishing) , the ecologcial logic is persuasive:
The study by Villy Christensen of the University of British Columbia's Fisheries Centre confirmed some previous indications that populations of predator fish at the top of the food chain, such as cod, tuna and groupers, have suffered huge declines, shrinking by around two-thirds in the past 100 years. More than half that decline occurred in the past 40 years.Christensen found that the total stock of "forage fish", such as sardines, anchovy and capelin, has more than doubled over the past century. These are fish that are normally eaten by the top predators. "You remove the predator, you get more prey fish," said Christensen. "That has not been demonstrated before because people don't measure the number, they don't go out and count them."
Every time I look at other fish that may be available to purchase and eat, there has to be a proviso -- a hesitancy -- about how it was caught and its sustainability. The fact is that most of the species that we eat aren't sustainable. Fish stocks have imploded world wide.
I like mussels and as far as I can tell, modern commercial mussel farming is both productive and does not pollute the local environment. The impacts of the mussel industry in South Australia and Tasmania is in sharp contrast to tuna aquaculture. There may be a case that other species aquaculture are sustainably grown but the problem with many aquaculture systems is that they require dense inputs of protein rich meal and high nitrate outputs.
In the wake of an extensive culling of the Australian fishing industry and the buy out of many commercial fishing licenses we are treated to this ongoing debate that centres supposedly on the right to fish. This exchange impacts on all attempts to create protection zones where fishing is disallowed.
When I study the fishing history of where I live -- the northern end of Moreton Bay -- what is clear is that a succession of industries have collapsed due to both pollution and over harvesting. (Let's not mention the Dugong!) There used to be fish canneries here, and a viable oyster farming community worked by local Indigenous peoples whose traditional middens still dot the lanscape. But today one small oyster farm remains and the keenest of local amateur fisher folk are hard pressed to catch their supper.
This environmental tragedy doesn't lend itself to too much pragmatism. Despite size and catch limits, recovery is an urgent quest.
But with sardines and anchovies, you can squeeze a lot of fish into a can.