© 2024 WUOT

209 Communications Building
1345 Circle Park Drive
University of Tennessee
Knoxville, TN 37996-0322
Play Live Radio
Next Up:
0:00 0:00
Available On Air Stations

Scientists map world's largest known deep-sea coral habitat


Now we want to take you to the bottom of the ocean, where scientists have discovered what they now characterize as the largest deep sea coral habitat to be mapped and documented.


DETROW: That's the sound of the Alvin submersible splashing down in the Atlantic Ocean in 2018. The dive was part of a multiyear exploration of an area roughly the size of Wisconsin, about 100 miles off the East Coast. Stretching from Miami, Fla., to Charleston, S.C., this underwater world is a rolling seascape of coral mountains. The scale of this habitat sheds some light on the impact that industrial activities like drilling and mining could have as they reach deeper and deeper underwater.

Erik Cordes is a biology professor at Temple University. He's one of the authors of a new study published in the journal Geomatics, which mapped this expansive coral habitat. And he's even been down there himself in a submersible. Welcome to ALL THINGS CONSIDERED.

ERIK CORDES: Thank you.

DETROW: I want to start with that last point before we get to the broader study. You've been down to this area yourself. What's it look like? How deep did you go?

CORDES: I have. It's a pretty amazing sight. It is about half a mile down. We started at about 900 meters depth and climbed up the side of one of these large coral mounds almost 100-plus meters, which is, you know, 300, 350 feet up, to the top of the coral mound. And it was just - it was live coral everywhere we could look once we got up to the top.

DETROW: I mean, I think a lot of us can envision more shallow coral. What does it look like at that depth? What were you seeing with your eyes?

CORDES: The deepwater coral reefs actually look a lot like the shallow water...


CORDES: ...Coral reefs. It's the same kinds of coral and the same family, not the same species. But this coral that forms most of this habitat is white, and it's naturally white because they don't have the photosynthetic algae in them that the shallow water corals do. We're much too deep for light to penetrate. But then there are other corals. There's a really high diversity here, all sorts of different colors, fish swimming around. I mean, it is a coral reef.

DETROW: So there's a lot of life down there despite the depth.

CORDES: There is. Yeah, there's actually really high diversity, rivaling that of the shallow water coral reefs. But the animals down here, because food is more scarce, they tend to be smaller and a little bit harder to find.

DETROW: Why is this area of such interest to researchers?

CORDES: Well, this study started when this area was under consideration for oil and gas leasing, and the Bureau of Ocean Energy Management funded a good portion of this study, along with the U.S. Geological Survey and NOAA, which is the National Oceanographic and Atmospheric Administration. And so we were looking at this area to find these potentially sensitive habitats to make sure that if our industrial use were to move into this area, that we would try and avoid as many potential impacts as possible.

DETROW: And then that gets to the broader paradox here because when you talk about deep sea mining, a lot of the interest in that has to do with electric cars, other green technology aimed at lowering the broader carbon footprint, but obviously has its own environmental concerns. You mentioned that was the impetus for beginning this research. Where does that possibility stand right now?

CORDES: Well, deep-sea mining is something that has been discussed for a long time, but the technology is finally to the point where we can begin to go to these places where these metals are very common. There are some reserves of these metals on the Blake Plateau, where this study takes place and where these coral reefs lie. The biggest deposits are out in the central Pacific, almost three to four miles deep. But even there, there's an incredible diversity of life and life that only survives on these metal deposits - the manganese and polymetallic nodules that are down there.

It's a resource that we obviously need to transition our economy and our energy systems for the battery technology that needs to come online for a lot of the electronics. But we need to be sure that as our industries move into deeper and deeper water, that we're doing the exploration in advance, so we know what kinds of impacts we're having. Otherwise, we're sending out these vehicles, and we're going to tap these resources before we even understand what's down there and what possible repercussions that could have.

DETROW: You've been down there. You've mapped and explored this area that most of us are never going to get a chance to see with our own eyes. I mean, in the end, what do you want people to know about this part of the ocean that you've seen? What's something that you want to get across that you wish you could just convey to somebody who hasn't been there in a submersible themselves?

CORDES: Well, people have this concept of the deep sea is this vast, featureless, muddy, dark, scary place (laughter).

DETROW: Yeah, I'm thinking of those, you know, strange fluorescent fish and things like that in my mind.

CORDES: Right. Those do exist. But you see those really blown up in the movies, like they're going to start running around eating people. And really, most of those fit in the palm of your hand. It's really not a scary place. It's beautiful. It's amazing. There are mountains and canyons and miles-long coral reefs down there, and it's really an amazing place.

DETROW: That's Erik Cordes, a biology professor at Temple University. Thanks so much.

CORDES: Thank you.

(SOUNDBITE OF MUSIC) Transcript provided by NPR, Copyright NPR.

NPR transcripts are created on a rush deadline by an NPR contractor. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.