Discovery Magazine

Photo Credit: Kathy Kuletz

Hanna Shoal (Chukchi Sea, Alaskan Arctic) Ecosystem Study

The U.S. Department of the Interior (DOI) funded this project to study the Hanna Shoal ecosystem in Alaska's Chukchi Sea. Trefry and scientists from Florida Tech join colleagues from the University of Texas, Old Dominion University, University of Alaska Fairbanks, University of Maryland, University of Rhode Island and Woods Hole Oceanographic Institution. More than $5.6 million, including ship time, was awarded for the study, which is ongoing until 2014. One of the goals of the study is to improve our understanding of arctic biogeochemistry so that we can identify impacts from local human activities. This includes impacts from oil exploration as well as from global climate change.

A total of 30 distinct stations will be sampled each year in the COMIDA-Hanna Shoal study area. Fifteen of these stations will be identified by a randomization technique in the Hanna Shoal study region and an additional 15 stations will be selected as “hotspot” locations based on water mass type and upstream/downstream location in a transect mode. The Florida Tech group will be studying the arctic biogeochemistry of selected trace metals including mercury, lead and cadmium in water, sediments and biota from the Hanna Shoal area. The biota to be analyzed include amphipods, clams, snow crab, gastropods and fish. The biota will be analyzed for mercury and methyl mercury as well as a large suite of additional metals. Both surface sediments and sediment cores will be collected. The sediment cores will be age-dated so that the Florida Tech group can look at the long-term history of metal deposition in the Chukchi Sea. Sediment cores also will be used to study diagenetic processes that affect the arctic biogeochemistry of metals such As, Cd and Mn. Water column profiles of dissolved and particulate metals will be obtained to trace the recycling of metals in the Chukchi Sea and to better understand the arctic biogeochemistry of nutrient-type metals.