There aren’t many people who would eagerly anticipate a phone call about a dead dolphin. Eddie Kisfaludy, marine biologist and National Geographic grantee, had the idea to try to document what happens once a dolphin carcass sinks to the seafloor. The idea came to him one day while he was offshore working with Scripps Institution of Oceanography, UCSD, and a dolphin was seen floating in the ocean. Fish and animals were beneath it. “Nobody has ever taken a dolphin like this and put it down on the seafloor to see what will happen,” Kisfaludy says. “Is it going to attract big fish? Are there going to be sharks or crabs? Is a big sea lion going to come down and tear it apart? What is going to happen next?”
Kisfaludy has led more than a thousand oceanographic and aerospace excursions around the world. He’s a jack-of-all-trades, doing everything from diving for new biological species to deploying and recovering massive amounts of marine instrumentation, so this challenge was right in his wheelhouse.
“Dolphins die in the ocean all the time,” Kisfaludy reminds us. “This one just happened to wash up on the beach [when] the Marine Mammal Stranding Network at NOAA gave me a call and said, ‘Hey, instead of putting [the dolphin carcass] in the dumpster, would you like to use this for your project?’ It was the perfect opportunity.”
You may have heard of a whale fall, when the carcass of a whale falls thousands of feet to the bottom of the ocean. Over time the carcass can sustain complex localized ecosystems. Kisfaludy says, “Scientists often take whales, sink them offshore, and put them next to a submarine canyon in the hopes that new species are going to infest the animal.”
The carcass will host an array of life, including single-cell bacteria, crustaceans, and sharks. He continues, “Because it’s difficult to stumble upon a whale or a dolphin on the seafloor, we have to put them down in a place that we know about so that we can revisit them over time to watch the animals, collect new species, and try to better understand what these deep-sea communities are like.” He was excited to document the same process but on a smaller scale.
They chose a place to lay the dolphin to rest, 180 feet down. It was shallow enough to access with scuba gear but deep enough to stay clear of all the large swells and storms that are typically offshore in Southern California. They took down hundreds, if not thousands, of pounds of gear without a crane, including anchors to hold the dolphin down, nitrox tanks, and lights.
“We actually had to build a massive structure that was about 10 feet tall to be able to mount the different cameras,” Kisfaludy says. “This whole structure had to be sunk down to the seafloor, and we strapped different cameras onto it to be able to get these different shots. We had to create an underwater soundstage for this all to take place, something that would stay there throughout storms.”
The time-lapse cameras shot continuously for at least six months. To see what happened naturally, the cameras had to be placed, and then the team had to leave. The presence of divers and the bubbles from the scuba diving equipment make lots of noise, which would scare away any other animals. There was an explosion of life— thousands of animals found the dolphin carcass. Kisfaludy says, “We do know that the deep sea is a very dark, cold, lonely place that doesn’t get many visitors. When a dolphin shows up from the surface, it’s a very exciting time for a deep-sea animal, because you now have a place to stay perhaps. You’ve got lots of food. This could be the biggest moment in your life to do what you need to do. If you’re a small worm or a crab, this might be the place where you’re going to start to reproduce. It’s a very important thing.”
Over months, this dolphin carcass became an ecosystem playground for crabs, octopuses, and eventually smaller to medium-size fish. At one point there were a thousand different large crabs that visited the carcass.
Kisfaludy says, “This project was one of the more difficult things that I’ve ever tried to do in the ocean, simply because it required lots of deep diving, huge amounts of equipment, [and overcoming] technical difficulties that we ran into, but all in all we were happy that we could tell this story for the first time with time-lapse that otherwise hasn’t been done before.”