Katlin Bowman

I am not a marine biologist - my own friends and family can't even keep this straight. When we think of oceanography, images of whales, dolphins, and diving in coral reefs come to mind. But there are many other ways, in addition to marine biology, that scientists study the ocean. Oceanographers are mathematicians, engineers, physicists, chemists, geologists, microbiologists. In this talk I share my experiences working as a chemical oceanographer using stories and images from 12 research expeditions spanning the globe.

Mercury is the most complex metal that cycles through our environment. Found naturally in Earth’s crust, solid mercury turns into an invisible gas when heated. Much like increasing carbon dioxide in the atmosphere from human emissions, mercury is also on the rise. Gaseous mercury can remain in the atmosphere for up to one year and as a results, mercury blankets our planet from pole to pole. No region is spared, not even the most remote corners of our planet. Mercury is transformed to an organic compound called methylmercury by bacteria found in soil and water. Methylmercury sticks to phytoplankton and algae, resulting in bioaccumulation, or increasing concentrations moving up the food chain. Humans are exposed to mercury through consumption of fish, and top predator species (i.e. Tuna, Swordfish, King mackerel) deliver the highest dose. This talk gives an overview of mercury cycling through the environment from human sources to seafood.

Many predatory marine mammals and seabirds in the Arctic contain high levels of mercury—a toxic metal known to disrupt neurological, cardiovascular, and endocrine systems. Varying levels of mercury in marine mammals throughout the Arctic point to a number of possible sources. Yet due to the remoteness and extreme conditions, there is little information about this. In 2015, a team of 50 scientists from across the United States spent more than two months on a Coast Guard icebreaker mapping the chemistry of the Arctic Ocean from Dutch Harbor, Alaska to the North Pole. As part of this team, Bowman is trying to understand how warming temperatures and disappearing ice cover will affect Arctic ecosystems during the next century.