STEVE INSKEEP, host:
It is very visible when a giant forest full of ancient trees is cut down, hard to miss the destruction.
But when similar changes take place at the bottom of the ocean, no one usually sees them at all. Off the coast to Florida, a remarkable set of old underwater photographs is helping scientists see exactly what's happened to a deepwater coral forest near Miami.
NPR's John Nielsen has more.
JOHN NIELSEN: Thirty years ago, nobody knew that there were deepwater coral reefs all over the world's oceans or that one of the best of them was 30 miles due east of Miami. Then, marine biologists in clunky, deep-sea diving suits started looking around.
One of those biologists was John Reed of the Harbor Branch Oceanographic Institution. He remembers the dive he made late one afternoon in the spring of 1976.
Mr. JOHN REED (Senior Scientist, Harbor Branch Oceanographic Institution): Distance is about 300 foot of water and is kind of twilight, everything is kind of gray and blue. And all of a sudden up ahead of me, I saw this giant, white structure looming up off the bottom, 60, 80-foot tall.
NIELSEN: It was a ridge made up of several thousand years worth of white, deepwater corals known as oculina. Reed says it looked vaguely like a bunch of bright white, leafless fruit trees. Fish and other sea life buzzed around the corals like a cloud.
Mr. REED: And as far as we know, this is the only place in the world where this type of coral forms massive reefs that are up to 100-feet tall, and they grow along the shelf-edge break of central and eastern Florida.
NIELSEN: Reed and his mentor, the late Robert Avent, took 70,000 pictures of these reefs in the late 1970s and early 1980s. Those photos helped make the oculina reefs a poster child for deepwater forests all over the world. They also helped convinced government officials to protect a few of the reefs in the Florida oculina system.
Unfortunately, Reed says that left all the other reefs in this system vulnerable to shrimp trawlers that drag heavy nets with big steel doors on them back and forth through the underwater forests.
Mr. REED: So imagine going over a fragile colony of porcelain-like coral, one pass would destroy thousands of years of growth.
NIELSEN: Six years ago, Reed went back into the water to find out what had happened to his reefs. He climbed into a tiny submarine, went back to the places where he'd taken those old pictures and took new ones. Then he carried the before and the after pictures back to his labs.
Mr. REED: And viewed them under microscope to figure out how much coral lived there in the 1970s and how much coral was still alive today.
NIELSEN: It took him years.
Mr. REED: What I saw devastated me. Instead of a 60-foot mound covered with thickets of thriving coral, I saw 60-foot mound of rubble. Every coral head was crushed to little pieces the size of my finger. I mean, I almost cried.
NIELSEN: Reed reports his findings in the Bulletin of Marine Science. He says the only oculina reefs still standing are the ones that got protected back in the 1980s.
Coral experts say Reed's findings are depressing but not all that surprising. They're well aware that trawlers have done huge amounts of damage to deepwater reefs all over the world. What's different here is the fantastic trove of photographs that show how quickly and how completely reefs like these can be erased.
Margot Stiles, a marine biologist with the nonprofit Oceania, says the photos also show exactly what's been lost.
Ms. MARGOT STILES: When you look at the areas that are untrawled, there are little fish sticking their heads out from between the branches and cute sort of mini-lobsters that are clicking their claws at the camera. And then you look at the trawled photos and you can recognize little pieces of the branches, and they're lying flat on this muddy bottom that stretches off out of your field of view into darkness.
NIELSEN: Stiles says it's now illegal to fish near any of the oculina reefs. She says biologists are trying hard to reseed and restore them, but oculina corals grow extremely slowly, Stiles says. For that reason alone, it's unlikely that anyone alive today will live long enough to see the reefs return.
John Nielsen, NPR News, Washington.