SEA Currents: News
June 21, 2018
Sailing for Seaweed 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.
Sailing for Seaweed in the Sargasso Sea:
Students Use Novel Genetic Techniques to Study Floating Gulfweed on the High Seas
June 11, 2018, Woods Hole, MA — SEA Semester students recently conducted molecular research on a 2,500-mile ocean voyage to explore the genetics of Sargassum, an ecologically vital floating seaweed. Their research fills gaps in understanding the overall health and function of the Sargasso Sea, a unique North Atlantic ecosystem.
The Sargasso Sea has puzzled voyagers and scientists for centuries. It’s the only sea in the world bound by ocean currents rather than land, and hosts the world’s only holopelagic seaweed, Sargassum. This seaweed can vary in size from large clumps to massive mats that span up 100 miles or more, providing habitat and nutrients to a host of organisms: over 100 species of fishes, around 145 species of invertebrates, and 10 endemic species.
Students Daniella Hanelin (Mount Holyoke College), Alena Anderson (University of California San Diego), and Jenny Renee (University of Washington) had the opportunity to help sail a 134-foot sailing research vessel, the SSV Corwith Cramer, on a 6-week voyage from Nassau, Bahamas to St. George’s, Bermuda, and to New York City. While the waves thrashed and winds blew, pipets in hand, these three scientists collected over 100 samples of Sargassum. They performed genetic analyses and found unique differences between the three most common forms of Sargassum, Sargassum natans I, Sargassum natans VIII, and Sargassum fluitans III, in two regions of the genome. Throughout their journey, they also analyzed distribution data of Sargassum, focusing specifically on spatial abundance and the age of Sargassum.
Even with satellite imaging, which has been used in the past to map Sargassum, species identification and genetic work can only be executed by field sampling. Sailing and collecting samples directly from the Sargasso Sea provided a rare opportunity to look and experience the physical differences between the forms of Sargassum as well as analyze them genetically in the field. The students were able to target distinct regions of DNA, using a newly designed genetic probe called a primer.
Their research confirms that these regions are effective genetic markers and can be used in the future to accurately identify Sargassum. More importantly, it is an essential step towards fostering knowledge and awareness of this unique ecosystem and promoting its conservation.