SearchResearch Challenge (10/19/16): How healthy is the Mediterranean?

A few weeks ago... 

... my travels took me on a tour of the Greek islands.  I don't know why they weren't on my bucket list before now, but they were such a beautiful place that I'll definitely return in the future.  It was that nice.  

On Santorini, the cliffside town of Oia overlooks the sea.

It's better than I ever imagined it to be.  The water is clear, the air is pure and sweet, the food is superb, and everywhere you go there's a sense of deep history.  

And, as you might expect, I spent one morning going on a dive.  The water wasn't just clear, it was crystalline clear.  When I asked the divemaster about it, he commented that the visibility was "only 30 meters"  (90 feet), on a good day "you can see at least 60 meters"  (180 feet).  That's astoundingly good, and I was optimistic that my dive off the shores of Crete would be just amazing.  

The crystal clear Aegean... 

As you can see, the water really is transparent (and a beautiful blue).  

So I was surprised when I saw relatively little sea life.  A few fish here and there, a fleeting sighting of an octopus, a bit of algae, and that's about it.  

Although I only dove the one time, everywhere I went in Greece I would stare into the water, looking for something with more life in it than the waters I saw.  Sadly, I didn't see much.  (Unfortunately, I didn't have my underwater camera with me...)  

My dive was about 2 km from here, just off the coast of Crete in an uninhabited area.

But it made me think:  Is this really the "normal" condition of submarine life around Greece?  What about the Mediterranean more generally? 

This leads me to this week's SearchResearch Challenge:  

1.  How healthy IS the Mediterranean?  Are there still places where one could go diving and see a rich, healthy, submarine Mediterranean ecosystem that's full of fish, invertebrates, corals, and other marine organisms?  Where should I go to have this experience?   (Note: Anything outside the Straits of Gibraltar, or the Bosporus Strait, or doesn't count.)   

More generally, I'm interested in how much the Mediterranean has changed over the past 100 years.  Has it always been like this?  Or has something changed recently?  

In my quick initial check to answer this question, I found that it wasn't exactly simple to answer this Challenge.  It's a large, difficult-to-frame question--but this kind of question is typical of the big research questions we want to answer.  This is smaller than "is global warming a real phenomenon," but larger than "what's the best pizza in New York City?"  There are also a fair number of authors who have a particular outcome that they're trying to get you to believe.  

I'm curious how you'd approach this kind of large-concept research question, so be sure to let us know HOW to approached the question, and how you assessed the information you found.  What resources look good to you?  Do you believe what they say?  

Obviously, you could write a book about this--but you don't need to--I'm interested in what resources you find and whether or not you believe what they say.  

I'll be working on this Challenge over the weekend and will post my results on Monday.  

Curiously, I say  "Search On!"