Where do deep-sea creatures live? Where they won’t dissolve

July 25, 2023 6:22 AM

Vast muddy seabeds cover more than 60% of the planet, collectively making them Earth’s largest habitat. At first glance, these frigid, sunless depths all seem more or less the same. Yet the animals that live there, kilometers below the surface, prefer some regions over others, according to a new study. What accounts for their preferences? It’s nothing they can see or sense, the authors say, but an invisible and life-threatening limit imposed by seawater chemistry. This limit demarcates where an important component of many kinds of marine life, calcium carbonate, naturally dissolves.
posted by Etrigan (16 comments total)

The more we learn about the deep sea the more worried I am about deep sea mining (which makes an appearance in the article), but I can't help but feel that it's potentially so "valuable" that it'll inevitably come to pass as a commonplace thing.
posted by coolname at 6:43 AM on July 25, 2023 [5 favorites]

Manganese nodules. Sure.
posted by Naberius at 7:15 AM on July 25, 2023 [2 favorites]

Not to derail but Hakai magazine has had a lot of good coverage on what's going on with deep sea mining.
posted by HumanComplex at 7:39 AM on July 25, 2023 [5 favorites]

The Economist had two fairly eyebrow raising articles promoting deep sea mining in the Clarion-Clipperton Zone recently. Short, Long. Also a podcast. The basic argument is "we need nickel to build batteries to fight global warming and hoovering them up off the sea floor is better than mining in rainforests".

It's all consistent with the Economist's general editorial voice. It's good reporting. But it felt pretty biased even to me, someone generally pro-development and sympathetic to hard tradeoffs. Now I'm wondering how those articles came to be in the Economist this month and whether there's some large international debate happening. Glad to see the pro-environment side presented here, and the biological discovery in the original post is really neat.
posted by Nelson at 7:46 AM on July 25, 2023 [5 favorites]

This kind of stuff just strengthens my belief in the idea that there is definitely weird life forms living in the layers of Jovian planets.
posted by snwod at 8:28 AM on July 25, 2023 [8 favorites]

Is there a map?
posted by rebent at 9:18 AM on July 25, 2023

To be fair, all creatures live where they won’t dissolve; it’s just that deep water makes that more… complicated.
posted by GenjiandProust at 9:28 AM on July 25, 2023 [9 favorites]

"OK, the next place I'm showing you is below the invisible and life-threatening limit imposed by seawater chemistry, which I know you said you didn't want, but there's a finished basement and a great elementary school a couple of blocks away so please try to keep an open mind..."
posted by PlusDistance at 10:12 AM on July 25, 2023 [24 favorites]

I remember watching an ocean documentary, and it featured a very deep water depression where, for reasons, the water could not hold oxygen, so it formed a sort of “lake” where anything that swam in would drown. It was surrounded by a plain of bivalves, which had a symbiotic relationship with bacteria that allowed them to process… methane? sulphur dioxide? Of course I turned to my viewing companion and said “hey, look, Mussel Beach!”
posted by GenjiandProust at 10:42 AM on July 25, 2023 [6 favorites]

The more we learn about the deep sea the more worried I am about deep sea mining

It's a reasonable worry.

Humans reach a new low. Literally! (Just Have a Think, YouTube, 14m42s)
posted by flabdablet at 12:04 PM on July 25, 2023

Yes, there's a reason deep sea mining is in the news right now: The UN International Seabed Authority has been having a conference on deep sea mining in Jamaica for the past 2 weeks
posted by hydropsyche at 1:01 PM on July 25, 2023 [4 favorites]

Thanks for that, hydropsyche! It jogged my memory to revisit the Economist article where I found this on second read

That date marks two years since the island nation of Nauru, on behalf of a mining company it sponsors called The Metals Company (tmc), told the International Seabed Authority (isa), an appendage of the United Nations, that it wanted to mine a part of the ccz to which it has been granted access. That triggered a requirement for the isa to complete rules on commercial use of the deposits. If those regulations are not ready by July 9th—and it seems they will not be—then the isa is required to “consider and provisionally approve” tmc’s application

Hakai Magazine, which HumanComplex linked above, has a specific article on Nauru: Why Nauru Is Pushing the World Toward Deep-Sea Mining. And The Guardian two years ago write an article when Nauru first filed its petition:

DeepGreen is in the process of merging with blank-cheque company Sustainable Opportunities Acquisition Corp (SOAC) to become The Metals Company. The Metals Company plans to list on the Nasdaq in the third quarter.

... DeepGreen has deals with Nauru, Tonga and Kiribati for CCZ exploration rights covering 224,533 square km, roughly the area of Romania.

DeepGreen / TMC's project with Nauru is called NORI. They say "In 2011, the International Seabed Authority (ISA) granted a polymetallic nodule exploration contract in the Clarion Clipperton Zone (CCZ) to NORI, sponsored by the government of the Republic of Nauru."

The ISA in turn is a transnational organization established by the UN to manage deep sea exploitation. Note that the CCZ is thousands of miles east of Nauru, in the middle of water outside any national jurisdiction. Presumably some process assigned exploration rights to various countries, including Nauru, on the assumption they would work with private companies to exploit any resources. DeepGreen is a Canadian minerals company.

So to put it all together.. The CCZ is an incredibly deep and remote part of the ocean floor, in international waters. It has some really interesting and unique ecology. A UN sponsored organization granted mining rights to parts of the CCZ to Nauru, which is developing them in partnership with a Canadian corporation. And the legal details are all coming to a head right now.
posted by Nelson at 1:18 PM on July 25, 2023 [3 favorites]

I'm sure that this will be managed with the same foresight and respect for sustainability that the phosphate mines and asset trust of Nauru were.
posted by tavella at 3:54 PM on July 25, 2023 [3 favorites]

To be fair, all creatures live where they won’t dissolve

crap, so that's what I've been doing wrong
posted by Flunkie at 5:54 PM on July 25, 2023 [2 favorites]

I too live where I won’t dissolve… at least not quickly.
posted by blue_beetle at 10:11 AM on July 26, 2023

This post reminds me of an article that discusses a creature that's got past the depth limit:

Amphipods—small, shrimplike crustaceans in most aquatic ecosystems—start to fall apart once they hit depths of 4500 meters. There, a combination of crushing pressures, low temperature, and higher acidity causes the calcium carbonate in their exoskeletons to dissolve, making them vulnerable to pressure and predators. Now, scientists have discovered how one species, Hirondellea gigas, can survive in the deepest part of the ocean: with aluminum suits of armor.

posted by Mister Cheese at 10:45 AM on July 26, 2023 [2 favorites]