An immediate ban on bottom trawling which ravages and wrecks the sea bed, ruining the marine ecosystem and so making it support less fish. Working to end all causes of marine pollution. Sensible quotas on fishing. Leaving some species as and when numbers dictate.

We must curb the amount of commercial fishing currently going on. In addition, the methods of fishing must change. Trawling nets and other nets kill coral reefs and have depleted many species of fish and sharks by as much as 90%. When the ecosystem becomes unbalanced enough, it will collapse. This will not only mean the end of many species and lack of food for man, but it could alter the oceans enough to cause widespread adverse changes. Changes will not happen if people don't speak up. Revolutions begin with a single voice. Vote, write your elected officials, join conservation groups. Act.

We must move from free-range fishing to farm fishing. I see a world where we have man made islands, large concrete structures which are more like "rings" with deep nets floating on the ocean's surface. Inside of those rings we are raising fish species in a habitat which they are used to and which is self regulating and can be moved to mimic the migratory patterns of many fish species. Not only that we can keep the species of fish we do not want out of the pens. Presently fish farming is on land, requires a lot of pumps and has many "problems" and is highly expensive. thus free fishing out in the open ocean is more desirable than farm fishing. As it is working out many species are on the brink of extinction, not only the ones we do want, but the ones that we throw out as waste product from net fishing. However as with all aspects of Humanity V Earth, Humanity needs to curb its behaviors. There are nearly 7 billion of us on a world which can sustain naturally (without all of our technology and chemicals) 500 million to one billion. We can safely push that number to 3 billion using "sane" and sustainable "green" farming and resource managements that we already know. We can not sustain 7 + billions and expect to feed, cloth, shelter, provide medical care for all equally. The best number to aim for would be 2 billion spread out evenly over the earth. If we tend to that we not only save fish, but we reduce greenhouse gas emissions (the modern car is highly clean compared to earlier times, the problem is not the individual car it is the high number of cars on the road), and many other things which over population is harming.