Some deep-sea shrimp, believed to be blind, travel great distances to reach their home — a boiling hot abyss at the bottom of the ocean with zero sunlight that's toxic to most other life.
Now, FIU marine scientist Heather Bracken-Grissom — along Tamara Frank, professor at Nova Southeastern University, Sönke Johnsen, full professor at Duke University and Jon Cohen, associate professor at the University of Delaware — hopes to uncover the secrets of these strange shrimp.
With a $1.35 million National Science Foundation (NSF) grant, the team will use cutting-edge technology, capable of descending to the crushing pressure of the sea floor where the shrimp live, to investigate them and their environment. Funding will support one postdoctoral scientist, as well as FIU undergraduate students, to help with the research.
Alvinocaridid decapod shrimp, or vent shrimp, swarm to the ocean’s hydrothermal vents. Discovered in 1977 and sparsely scattered across mid-ocean ridges, the vents resemble tall chimney-like structures that spew clouds of toxic chemicals reaching upward of 700 degrees.
Some species of vent shrimp crowd together in the thousands on the sides of these vents, forming patches of ghostly white. It’s the equivalent of living on the side of a volcano.
But, vent shrimp aren’t born there. As larvae, they can live 300 to 3,000 feet away from the hydrothermal vents.
“There’s a lot of mysteries surrounding these shrimps, like how do they even find the vents,” Bracken-Grissom said. “Is vision involved in the detection over short distances, and once there, how are they so successful? We’ll hopefully be able to answer some of these questions.”
This marks Heather Bracken-Grissom’s fourth major NSF grant. The marine evolutionary biologist has made groundbreaking scientific contributions and is known for her expertise in evolution, biodiversity and conservation of marine animals and plants.
When vent shrimp were first discovered in the 1980s, it's been thought they were blind. Some species don't have typical eyes, but a structure that appears like large white wings on their back — later discovered to be a huge dorsal-fused eye. Other studies, though, concluded these were non-functional.
The current team is not quite convinced.
Previous vent shrimp were collected under the bright lights of a submersible, probably too harsh for the shrimps’ sensitive eyes, rendering them blind. So first, the researchers will examine the visual systems of the vent shrimp to determine if they are blind or not. Then, they want to understand if the fused eyes sense light to locate the vents.
“I’ve been wanting to work on these shrimp ever since I read the papers from 30 years ago that suggested they had non-functional eyes,” said Frank, the lead PI at Nova Southeastern University. “I just can’t understand how they could undergo such a massive metamorphosis from stalked juvenile eyes to huge dorsal adult eyes to produce a non-functional eye.”
Better understanding the vent shrimps’ vision could also open the door to other exciting innovations, such as extremely sensitive light receptors, and even serve as a model for low-light camera systems — similar to how the optics of lobster eyes served as a model for designing an ultra-sensitive X-ray telescope.
Another objective of this project is to search for new sources of bioluminescence around hydrothermal vent systems, which have never been documented before.
Researchers will rely on a remote-operated vehicle (ROV) that can be controlled from the ship to reach the vents and explore the shrimp and bioluminescence. Essentially a giant robot, the ROV will collect samples and high-resolution video, using special methods the team has developed over the decades to collect deep-sea species without blinding them.
“This is a lifelong dream of mine to study these habitats. Ever since I was in grad school and learned about these weird, blind shrimp at the vents, I wanted to study them,” Bracken-Grissom said. “Now, here I am, all these years later — and I’m actually going to do it.”
The team of researchers who will join Bracken-Grissom have been with her on other exciting, historic missions — like when they captured the first-ever video of a giant squid in U.S. waters in 2019.
This award marks Bracken-Grissom’s fourth major NSF grant. Bracken-Grissom has made groundbreaking scientific contributions, known for her expertise in evolution, biodiversity and conservation of marine animals and plants. She’s assistant director of the Coastlines and Oceans Division in the FIU Institute of Environment and also runs the Crustacean Genomics and Systemics Lab (CRUSTOMICS).