In December 2000 while exploring the depths of Sodwana Bay, South Africa, scuba diver Pieter Venter came face-to-face with something no diver had ever seen alive before. At 320 feet, he and his colleagues encountered a coelacanth, an extremely rare type of fish that has existed for 400 million years—well before the time of the dinosaurs. The team recorded three fish in the area on that dive and in a later expedition, confirmed that a colony of these so-called “living fossils” lurked in deep water canyons in the bay. That colony of about 30 fish has more or less been left alone for the last two decades, but Tony Carnie at The Guardian reports that oil and gas drilling in the area may threaten the endangered species in the near future.
For decades, paleontologists knew about the human-sized coelacanth from the fossil record. It was believed the big fish went extinct 65 million years ago during the same event that put an end to dinosaurs. But in 1938, a fishing trawler working along the coast of South Africa alerted a local museum that they had found something strange in its nets. It turned out to be a living coelacanth. The creature was a sensation, proof that life is more resilient than we imagine and a reminder of how little we understand the oceans.
Last week, the Italian energy group Eni announced plans to drill in an exploration area known as Block ER236, a 250-mile long area just 25 miles south of Sodwano Bay, which is off the shore of iSimangaliso Wetland Park. In their environmental impact statement, the company says that it is unlikely that coelacanths live in the deep underwater canyons in the exploration area since the morphology is different than the shallower canyons they prefer in Sodwano. They also write that modeling shows no threat from oil spills.
But conservationists disagree. Andrew Venter, head of the South Africa group Wildtrust, tells The Guardian’s Carnie that an oil spill in the area could be a disaster. “The Deepwater Horizon oil spill in the Gulf of Mexico in 2010 decimated fish populations – so if we had an oil spill off iSimangaliso it is very likely it could wipe out these coelacanths.”
South African ichthyologist and author Mike Bruton agrees that drilling in the area threatens the fish, and that anything that could interfere with their ability to absorb oxygen could harm them. “The risk needs to be carefully evaluated before this commercial venture has progressed too far and it is too late,” he said. “Oil spills do not respect the boundaries of marine protected areas.”
John Platt at Scientific American reports that this isn’t the only threat to coelacanths. The West Indian Ocean population, which includes fish along the coast of Africa and in the Comoros, is estimated to be between 230 and 650 fish. In the last couple decades, deep water fishing trawlers along the coast have pulled up many coelaconths, revealing new populations but also reducing their numbers. There are more specific threats as well. Tanzania is expected to begin construction of the industrial Mwambani Port Project soon in the Tanga Coelacanth Marine Park, which is expected to disrupt the habitat of the rare coelacanths that live there.
Keeping coelacanths around, however, is important. These strange and little understood creatures are a link to nearly half-billion years of evolutionary history and there’s a lot they can teach us about primitive fish. They have weird fleshy fins that they move in a walking motion, a partial vestigial lung inside their chest and a unique hinged jaw that allows them to open very, very wide. They live to be 100 years old and give birth to live young. They also have a special rostral organ in their nose that allows them to sense electrical currents. And they do all that with a tiny, tiny brain that fills less than 2 percent of their head.
Somehow all of that came together to produce the ultimate, albeit odd, survivor. But the big takeaway is this: if a fish in the deep sea can survive 400 million years of comets, volcanic eruptions and everything else history has thrown at it but can’t survive a couple hundred years of industrialized humanity, there’s little hope for the millions of other species on the planet, including us.