SEA Currents: News
June 27, 2018
A study in Seaweed… Research in the Sargasso Sea
SEA Semester students of the Marine Biodiversity & Conservation program (Class C-279) recently completed their research voyage from Nassau, Bahamas to New York, with a stop in Bermuda. The program culminated with several weeks on the Woods Hole campus, and presentation of student research at the Ned Cabot Marine Biodiversity & Conservation Symposium. As part of their curriculum, students prepared press releases describing their research. These releases will be published here, on the SEA Currents blog, over the course of the next two weeks.
A study in seaweed: SEA Semester students conduct conservation research in the Sargasso Sea
June 16, 2018, Woods Hole, MA - SEA Semester students recently embarked on a 2,000-mile ocean research voyage to study hydroids, a small stationary animal related to jellyfish and corals, and to analyze the distribution of Sargassum seaweed in the Sargasso Sea. The research adds to a growing body of knowledge regarding hydroids, which are understudied but may provide important clues to better understand the ocean.
The student researchers, Carly Carter (Longwood University), Alex Merkle-Raymond (Northeastern University), and Kendra Ouellette (Bennington College), spent almost six weeks adventuring the high seas aboard the SSV Corwith Cramer from Nassau, Bahamas to New York City with the SEA Semester Marine Biodiversity and Conservation program. The Sargasso Sea is the only sea on earth bounded by ocean rather than land. It is a low nutrient locale and often referred to as a “blue desert,” yet it is home to vibrant communities of life dependent on Sargassum, a floating macroalgae. The seaweed rides the ocean currents through the Sargasso Sea and provides an environment for small creatures such as shrimp, crabs, sea slugs, frogfish, and hydroids to coexist. While hydroids contribute to the foundation of the Sargassum-dependent food web and community, the intricacies of their settlement patterns are not fully understood.
Since 2011, beaches and coastal communities across the United States and greater Caribbean have been deeply affected by Sargassum, as thousands of pounds of the macroalgae have been washing up on beaches and devastating local economies. The culprit, a form of Sargassum called Sargassum natans VIII, was previously deemed a rare species, but is now appearing in volumes large enough to disrupt tourism and destroy beaches with its choking mass. Methods of preventing and predicting these events are therefore vital for the well being and prosperity of affected communities, but not well established.
Hydroid research may provide a piece of the larger puzzle that will help unlock the mysteries of these inundation events. The research reveals that the hydroids living on this form of Sargassum are genetically distinct from hydroids on all other Sargassum forms, which implies that this Sargassum originates in a different part of the ocean. Further oceanographic research is needed to solve this puzzle, but in the meantime, hydroids themselves are in need of further study as well. To quote SEA First Scientist Kelsey Lane, “Hydroids are easily overlooked, but their many species provides a unique look at the diversity of the Sargasso Sea. Through this year’s research we can even look at the colonization of the seaweed Sargassum throughout different regions of the North Atlantic.”