The Aquarium is sponsoring an expedition to explore seamounts, or underwater volcanos, in Costa Rica, along with several leading underwater exploration and research groups. Over the next couple weeks, look for stories and pictures about this expedition from Aquarium explorers. Learn about previous expeditions to study seamounts in the Sea of Cortez and Raja Ampat, Indonesia.

Today's post comes from Dr. Larry Madin, New England Aquarium Overseer and Executive Vice President and Director of Research at Woods Hole Oceanographic Institution.

While our sub and ROV are focusing attention on the biology of the seamount, others are looking at what lives in the waters above it. Here, 400 miles from shore, we are in open ocean waters, and the water column is home to many different kinds of jelly-like planktonic animals. Groups of divers venture into the upper waters, held by safety lines to keep them from drifting off, and look for the jellyfish and similar animals that float or swim in the clear warm waters.


In the first few days here the prevailing current was from the southwest and brought oceanic species that we would also see in the middle of the Pacific--comb jellies, Pelagia jellyfish, and salps.




After a few days the current shifted, coming instead from the east and coastal waters of Central America. Now there was murky water with few animals but bits of floating plastic and other trash. After another couple of days it shifted again, restoring the community of floating and swimming plankton. Diving in this infinite blue environment is a reminder that we are seeing what 99% of the ocean is like--clear water that is home to diverse, unusual and rarely seen animals that are some of the most abundant creatures on Earth. We get a brief glimpse into the heart of our ocean planet.

Do you like sea jellies? Read this post about blue water diving with Dr. Madin in the Phoenix Islands during a 2009 expedition. Don't miss these salp sightings in the Red Sea from a 2011 expedition and be sure to browse the Aquarium's Exhibit Galleries Blog posts about jellies to learn more about these fascinating animals.
 
For more pictures and stories from this expedition to Costa Rica, follow Greg Stone on Conservation International's blog as he prepares for this expedition and finally sets foot in Costa Rica.