A problem for as long as I can recall. Many years ago I was something of a 'Save the Whales' type because that wasn't really about hugging whales but about a need for some international agreements regarding all harvesting of the oceans. Since then there have been some agreements and, I think, all nations with a coast have claimed fishing rights out to 200 miles.
I see two approaches to stuff like this. The left always wants to force everybody to cut back and do with less. They really have that whole suffering, deprivation and misery thing down pat.
The right, that is, everybody else who doesn’t have hang ups like the left, wants more and better and cheaper. And they almost invariably win, because they put the time, effort and energy into problem solving, instead of just whining and demanding things.
An excellent example are a small group of scuba divers who spotted a serious problem, that the “arable ocean” off the west coast had been pretty well reduced to underwater desert over many years.
So without making a fuss, they got a bunch of empty bleach bottles, chopped off their bottoms, and tied them to a string and a brick. In each one they tied a runner of giant sea kelp. They would dive down and plant some in an area, and within a few weeks, the rapidly growing giant sea kelp would make a kelp bed.
And there is nothing like a kelp bed to cause an explosion of life. The west coast is now abundantly full of all sorts of ocean critters.
The big motivation wasn’t to “save the world”, just that they wanted something to look at when scuba diving.
This is why aquaculture has such promise. Most of the ocean is pretty barren. But with a little nudge here and there, you can get an explosion of life.
Another discovery was that underwater cable with a small current flowing through it, has a magnetic-like attraction to coral, which latches on to the cable and grows at perhaps five times its normal rate. So somebody has laid a grid of cable on a section of barren coast off of Africa, and has it hooked up to a battery for the right kind of current flow. They figure than in just a few years, they will create a new coral reef out of the blue. And that is very good for critters as well. If the test is successful, they plan to try it in the Gulf of Mexico.
Fish farming of endangered fish also has a lot of potential, because it is relatively inexpensive to have drop nets, pontoons, etc. A single operation could radically increase the numbers of that species, then set them free to fend for themselves. It’s even better, because they would be well fed and healthy, unlike the typical wild members of their species.