What do the oceans need from us?

Well, they need a lot.  But there are some hard truths as we think about marine conservation.
The first is that several billion people need protein, and most are not going to switch to soybeans anytime soon.  Fishing can't be stopped.  But it has to be better controlled. 
We're doing something called "fishing down the food chain." As the big fish like halibut are depleted, we catch the smaller fish they used to eat. What's next? There are already fisheries for krill.  We're facing the age of slime, where the dominant creatures of the oceans could be jellyfish.  There are fisheries for jellyfish (more properly "sea jellies," but it's not catching on, no more than "sea stars" has for starfish), but they are small scale, and people are not lining up in most nations for the little nutrition available from them. 
The point is that sharp limitations on fishing are necessary but hard. They affect the livelihoods of millions of real people and the protein sources of billions. Those people need other work and other food sources.  Part of the answer is properly regulated fish farming. I certainly don't know all the answers.
I'm not one of the people calling for huge transfers of wealth - that's a one-time thing, not a permanent answer.  But this is going to cost all the people who can afford to downsize a little - me, for one.  And I'm good with that, although I'd much rather do my share by giving to effective organizations I choose than by having the government choosing for me.
It's not yet not hopeless.  Institutes like this are looking for solutions. As Sylvia Earle (nicknamed "Her Deepness" by admirers, of whom I am one) says, "We have time, but not a lot of time."
What does this have to do with my usual themes of zoological discoveries and cryptozoology? A lot.  There are thousands, perhaps tens of thousands, of fish species we've yet to discover. There are denizens of all types - sharks, octopus, squid, even cetaceans - we've not named yet.  And there are, just possibly, a couple of animals the size of beaked whales or larger that have spawned the legends of the "sea serpent."
The way we're going, we're going to finish the job of cutting the food sources out from under the large marine animals - known and unknown - that so fascinate us.  The eel or pinniped or whatever it is that constitutes the true sea serpent could pass from the scene before we even confirm it was here.
So think about what you can do.  The oceans need our help.  The sea serpent, whatever and wherever it is, needs our help, too.