If the dams are not removed, new restrictions on logging, fish harvest, shipping channel deepening, and irrigated agriculture would be needed to avoid the extinction of five runs of Snake River salmon and steelhead, the paper says.

CNN: Salmon Swimming

Thanks to government subsidies of fishing industries around the world, there are 2.5 times more fishing boats than are needed to sustainably harvest fish.

FORBES: Carbon Emissions Threaten The Fishing Industry By Shrinking Fish Sizes

"Anywhere you go and try to harvest fish with a trawl you are going to destroy any coral that lives there, and there is example after example of the damage that is done by trawlers, " says Ron O'Dor, a senior scientist on the Census of Marine Life.

CNN: SHARE THIS

But, of course, how we harvest the fish has a direct impact on how many are left to catch next time.

CNN: A royal plea for sustainable fish and chips

The annual harvest, including fish farms, amounts to about 2m tonnes or roughly twice the catch from the North Sea.

ECONOMIST: The Mekong river

Fishermen need to have a secure income that is not tied to what they can catch, but rather how sustainably they manage fish stocks and how efficiently they harvest an agreed surplus.

BBC: Casting a net far into the future

Under current legislation, the department of fish and game is required to track Australia's kangaroo harvest and provide details to the government.

BBC: California's Jerry Brown ends 'unnecessary' briefings

Increased protection of natural fisheries is leading to better returns for at least some fish farmers, who now account for half the world's aquatic harvest.

FORBES: Swimming in Prosperity

Teams of Japanese inspectors fly into Port Lincoln to examine each harvest before it's flown off to Narita and trucked to the giant predawn Tsukiji Fish Market.

FORBES: The Future Is Fish