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Midwater Ecology Expedition Summer 2019 – Log 5

Tetrorchis is a small but beautiful jelly that twitches luminescent lures at the ends of its tentacles to “fish” for its prey.

Midwater Ecology Expedition Summer 2019 – Log 5

Content Manager Nancy Barr

The stunning jellyfish exhibit at the Monterey Bay Aquarium provides visitors a special glimpse into the wondrous diversity of life in the deep sea—the largest habitat on Earth. These animals are part of the intricate marine food web. Successfully exhibiting jellies at the aquarium takes a team of aquarists, including Tommy Knowles, who joined us on this expedition.

Tommy started this cruise with a wish list of specific jellies he was looking for. As the pilots of the ROV Doc Ricketts flew the vehicle hundreds of meters below the surface, the scientists focused on a steady stream of marine snow, looking to pick out the tiny animals scattered among the detritus. When one of these deep-sea experts spotted a jelly, they’d yell “stop!” The pilot then maneuvered the vehicle close to one little jelly. If the jelly was needed for the aquarium, the animal was collected either by suctioning it gently into a bucket or maneuvering the entire vehicle to enclose the animal into a container. This takes an extraordinary amount of skill on the part of the ROV pilots; it’s like trying to catch a butterfly by driving a big truck forward and back, left and right, to track the butterfly until an open window lines up perfectly with the butterfly’s trajectory. In other words—very difficult!

Over several hours of exploring from 200 to 600 meters (about 660 to 2,000 feet) deep, Tommy collected a wide array of jellies. These animals are important to the  aquarium’s research and development on the best ways of caring for jellies, and how to culture them to  keep exhibits well-stocked. This effort helps bring a bit of the deep sea to millions of visitors at the Monterey Bay Aquarium. The aquarium’s jelly collection also helps MBARI’s researchers study important properties like bioluminescence.