Marine Chemistry & Geochemistry
Research activities in the Marine Chemistry and Geochemistry (MC&G) Department are focused on exploring the broad spectrum of processes that influence chemical cycling in the oceans and their interactions with the atmosphere, land, and Earth’s interior. Critical to these efforts are considerations of how ocean chemistry influences and responds to biological activity and the impact of anthropogenic activity on the marine environment. We are a diverse group of researchers working at the interface of multiple disciplines using a combination of laboratory, field-based, and computational approaches. Projects range in size from single investigator studies to large collaborative projects involving investigators from multiple institutions. Below are highlights of just a few of the MC&G activities that occurred in 2013.
Completion of a newly fabricated mesocosm lab—a structure built to create and study small-scale ecosystems—on the Quissett campus allowed assistant scientist Amanda Spivak to initiate experiments focused on carbon cycling processes in coastal habitats. One experiment was highlighted in a video produced for WHOI's Oceanus Magazine (see video on right). In this experiment, Spivak and colleague John Pohlman (USGS) used stable isotope probing techniques (a way to track elements through food chains) and novel laser-based gas analyzers to examine the fate of carbon recently photosynthesized by the salt marsh grass Spartina alterniflora. Understanding carbon dynamics in salt marshes is important for evaluating how well these ecosystems sequester carbon over different time scales.
Assistant Scientist Scott Wankel completed field campaigns on the island of Sylt in Germany and Santa Catalina Island off the coast of California for his NSF-funded study investigating the role of intertidal sediments in producing and regulating the release of nitrous oxide, a potent greenhouse gas. This study brings together sophisticated analytical approaches that will improve our understanding of how microorganisms that contribute to the production of greenhouse gases will respond to impending environmental change.
A study published in Science by associate scientist Colleen Hansel’s research group (postdocs Julia Diaz, Peter Andeer, and Tong Zhang), in collaboration with a colleague at the Colorado School of Mines, discovered that marine bacteria, encompassing a wide ecological and species diversity, produce high concentrations of superoxide within marine waters. Superoxide is a form of oxygen that impacts many biogeochemical cycles and is essential for life at low concentrations, but at high concentrations is toxic and ultimately fatal. Previously known sources of superoxide to the ocean were limited to reactions with light. Thus, this new source expands our understanding of the relevance of these highly reactive and toxic compounds to the approximately 95 percent of our global habitat untouched by light.
Associate scientist Liz Kujawinski and research specialist Dr. Krista Longnecker led a cruise in the western Atlantic Ocean from Montevideo, Uruguay to Bridgetown, Barbados aboard the RV Knorr to investigate dissolved organic matter composition and microbial metabolism in the context of physical water properties associated with surface currents and deep water flow. The cruise involved a broad interdisciplinary group of researchers who came together to collect complementary chemical, biological and physical samples and measurements. Their results will provide unique insights into carbon cycling in the surface and deep oceans. In addition to Liz and Krista, other participants from MC&G included associate scientist Ben Van Mooy, research assistants Catherine Carmichael and Justin Ossolinski, postdocs Colleen Durkin and Carly Buchwald, and Joint Program students Winn Johnson, Harriet Alexander and Evan Howard.
Several members of MC&G were involved in the East Pacific transect of the US GEOTRACES Program cruise, led by Chris German (G&G Department) and former MC&G scientist Jim Moffett, from Manta, Ecuador to Papeete, Tahiti. Drs. Phoebe Lam, Matt Charette, Ken Buesseler, Carl Lamborg, Mak Saito, Bill, Jenkins, and Dan Repeta are all principal investigators in this highly coordinated effort to simultaneously measure a broad spectrum of trace metals and isotopes in the Eastern Pacific. Their results will allow a far richer and deeper interpretation of the data and help identify the processes and quantify the fluxes that control distributions of trace elements in the ocean. Even with limited berths available on the ship, MC&G was also represented on the cruise by Joint Program students Erin Black, Nick Hawco, postdoc Daniel Ohnemus, Research Associate Steve Pike, and Research Assistant Gretchen Swarr.
Senior scientist Ken Buesseler established a new Center for Marine and Environmental Radioactivity (CMER) that is focused on increasing scientific and public understanding of the sources, fates and consequences of natural and human-made radioactive elements in the environment, in particular the oceans. In keeping with this theme, Ken organized a Morss Colloquium at WHOI in May, 2013 on Fukashima and the Ocean. The colloquium provided a forum to discuss lessons learned from the Fukashima disaster with policy makers, media, and a broad public audience.
In July 2013 Senior scientist Scott Doney testified before the U.S. Senate Environment and Public Works Committee Hearing on Climate Change: It’s Happening Now. His testimony addressed ocean climate change, the ocean carbon cycle and ocean acidification, addressing how rising atmospheric carbon dioxide levels alter seawater chemistry, put at risk a wide range of marine life, and affect coastal communities and economies.
Several members of MC&G received recognition for their accomplishments through awards and promotions. Scott Doney received the 2013 A.G. Huntsman Award for Excellence in Marine Science from the Royal Society of Canada for his numerous contributions to chemical oceanography. Ken Buesseler was elected as a foreign member of Royal Netherlands Academy of Arts and Sciences for his pioneering role in detection and interpretation of radioactive plutonium in the oceans resulting from nuclear bomb tests, as well as other contributions to marine chemistry. Ken also received a prestigious fellowship from the Japan Society for the Promotion of Science that will allow him to spend significant time in Japan during 2014 to visit with a variety of groups to discuss mutual scientific interests and future activities related to the Fukashima nuclear power plant disaster. Ben Van Mooy was selected as a Kavli Frontiers of Science Fellow by the Kavli Foundation and also received a Diamond Jubilee International Visiting Fellowship from Southampton University. Research assistant Justin Ossilinski received WHOI’s Ryan C. Schrawder Award for 2013.
The list of 2013 promotions includes Liz Kujawinski to Associate Scientist with Tenure, Aleck Wang to Associate Scientist without tenure, Dawn Moran and Kristen Rathjen to Research Associate II, Zoë Sandwith and Gretchen Swarr to Research Assistant III, and Athena Aicher and and Hilary Ranson to Research Assistant II.
2013 saw the addition of two new members to MC&G. Jenny Rheuban joined the Department as a Research Associate II and Kristen Whalen as a Research Associate III.
—Jeffrey Seewald, Department Chair