“The ‘underwater turbulence’ the jellies create is being debated as a major player in ocean energy budgets,” says marine scientist John Dabiri of the California Institute of Technology.

Jellyfish are often seen to be aimless aquatic drifters, propelled by nothing but haphazard currents and waves, but the truth is that these gooey creatures continuously contract and relax their bells to move in desired directions.

The jellyfish Mastigias papua carries algae-like zooxanthellae within its tissues from which it derives energy and since the zooxanthellae depend on photosynthesis, the jellyfish has to stay in sunny locations. Research carried out in the so called Jellyfish Lake, located in the island nation of Palau 550 miles east of the Philippines, shows that this jellyfish doesn’t rely on currents to bring it to sunny spots – it willingly budges through the lake as the sun moves across the sky.

In Jellyfish Lake, enormous congregations of Mastigias papua can be found in the western half of the lake each morning, eagerly awaiting dawn. As the sun rises in the east, all jellyfish turn towards it and starts swimming towards east. The smarmy creatures will swim for several hours until they draw near the eastern end of the lake. They will however never reach the eastern shore, since the shadows cast by trees growing along the shoreline cause them to stop swimming. They shun the shadows and will therefore come to a halt in the now sundrenched eastern part of the lake. As the solar cycle reverses later in the afternoon, millions of jellyfish will leave the eastern part of the lake and commence their journey back to the western shore.

Together with his research partner, marine scientists Michael Dawson of the University of California at Merced, John Dabiri have investigated how this daily migration of millions of jellyfish affects the ecosystem of the lake.

What the jellies are doing, says Dabiri, is “biomixing”. As they swim, their body motion efficiently churns the waters and nutrients of the lake.

Dabiri and Dawson are exploring whether biomixing could be responsible for an important part of how ocean, sea and lake waters form so called eddies. Eddies are circular currents responsible for bringing nitrogen, carbon and other elements from one part of a water body to another. The two researchers have already shown how Jellyfish like Mastigias papua and the moon jelly Aurelia aurita use body motion to generate water flow that transports small copepods within jellyfish feeding range; now they want to see if jellyfish movements make any impact on a larger scale.

“Biomixing may be a form of ‘ecosystem engineering’ by jellyfish, and a major contributor to carbon sequestration, especially in semi-enclosed coastal waters,” says Dawson.

A group of scientists from the Catalyst One expedition has discovered three previously unknown coral reefs 35 miles of the coast of Florida. The coral reefs consist mainly of Lophelia coral and are located at a depth of 450 metres (1475 feet).

Lophelia pertusa is a cold-water coral famous for its lack of zooxanthellae. The well known coral reefs found in warm, shallow waters – such as the Great Barrier Reef – consist of reef building corals that utilize energy from the sun by forming symbiotic relationship with photosynthesising algae. Lophelia pertusa on the other hand lives at great depths where there isn’t enough sunlight to sustain photosynthesising creatures, and survives by feeding on plankton.

The deep-sea reef habitat formed by Lophelia pertusa is important for a long row of deep water species, such as lanternfish, hatchetfish, conger eels and various molluscs, amphipods, and brittle stars. The reefs that we see today are extremely old, since Lophelia reefs typically grow no more than 1 mm per year. Unfortunately, these deep reefs are today being harmed by trawling and oil extraction.

The Catalyst One expedition will submit its newly acquired information to the South Atlantic Fisheries Management Council to provide further data for the proposed Deep Coral Habitat Area of Particular Concern (HAPC).

The Catalyst One expedition is a collaboration between the Waitt Institute for Discovery, the Harbor Branch Oceanographic Institute at Florida Atlantic University, and Woods Hole Oceanographic Institute. It combines the scientific expertise of Harbor Branch’s senior research professor, John Reed, with Woods Hole’s high-tech operations skills and Waitt Institute’s modern autonomous underwater vehicles (AUVs).

In order to reach these great depths and efficiently explore substantial areas, the expedition used REMUS 6000 AUV vehicles capable of carrying two kinds of sonar and a camera. With this type of equipment, each mission can last for up to 18 hours and provides the researchers with mosaic pictures of the bottom, pictures that can then be pieced together to form a detailed, high-definition map.

“Rarely do scientific expeditions produce solid results this quickly,” says Dr Shirley Pomponi, executive director of Harbor Branch. “This is a big win for the resource managers tasked with protecting these reefs and proof that cutting edge technology combined with the seamless teamwork of the three organisations involved in Catalyst One can accelerate the pace of discovery.”

You can find more information about the Catalyst program at the Waitt Institute for Discovery.

http://waittinstitute.org/wid/catalyst/

http://waittinstitute.org/wid/news/catalyst1.html