CoastLine: How learning about deep-sea animals, including (and especially!) the eyeballs of shrimp, changes how we think about life in the deepest parts of the ocean
Researchers were shocked to find that the eyeballs of shrimp develop, not based on how deep they live in the ocean, but by the animal's ability to emit light through bioluminescence and the need they have to see the signals from other deep sea animals. In other words, the need to communicate could be a key factor.
Dr. Lorian Schweikert also details how their underwater camera captured the first video ever of a giant squid in the Gulf of Mexico.
A ship carrying 23 people sets out from Gulfport, Mississippi into the Gulf of Mexico in 2019. The expedition is called Journey Into Midnight: Light and Life Below the Twilight Zone. The mission: to explore the water column in some of its deepest areas. Scientists want to find out what happens to deep sea animals when they don’t have one element of life that we take for granted: light.
The researchers needed to go deep: more than three-thousand feet down into the darkest depths of the ocean. It’s too deep for any human to venture, so they used an underwater camera, dubbed Medusa, and a remotely operated vehicle called the Global Explorer. They also dropped a basic trawl net into the depths. They were sending these devices into the bathypelagic zone – also known as the midnight zone – because sunlight cannot reach it. The only source of light here: bioluminescence.
Scientists expected to find that the visual systems – the eyes – of deep sea animals would be shaped by factors like how deep in the water column they live.
But researchers were shocked to find that their visual systems are shaped by the animal’s ability to emit light through bioluminescence and the need they have to see the signals from other deep sea animals. In other words, the need to communicate could be a key factor.
Dr. Lorian Schweikert was one of the scientists on that expedition. On this edition of CoastLine, we learn more about what she discovered, why it changes the way we think about the deep and the function of bioluminescence, and what it means for those of us who are terrestrial.
Dr. Lorian Schweikert, Assistant Professor, Department of Biology and Marine Biology, University of North Carolina Wilmington