About the Hanna Shoal Ecosystem Study

The northern Chukchi Shelf receives extraordinarily large inputs of organic matter advected from the highly productive shelf regions of the North Pacific and from in situ sources of primary production, including epontic ice algae, sediment microalgae and phytoplankton. These contributions of highly labile organic carbon, together with potential benthic sources of regenerated inorganic nitrogen, probably contribute to the enormous secondary production of this region. In particular, the relatively shallow depths (40-55 m) and appreciable bottom flow facilitate high standing stocks of biota, particularly in the benthos. These “hotspots” have been noted in the vicinity of Hanna Shoal, particularly along its southeastern and eastern margins.

The Hanna Shoal Ecosystem Study is a multi-disciplinary investigation to examine the biological, chemical and physical properties that define this ecosystem. The study extends the monitoring initiated under the COMIDA CAB program, in which over 70 stations were occupied in the northern Chukchi Sea with a focus on trophic structure, sediments, inventories of anthropogenic chemicals (trace metals and organics), and inventories of benthic and epibenthic fauna. The Hanna Shoal study adds (1) a pelagic component to address standing stocks of phytoplankton and zooplankton and (2) a physical oceanographic study that addresses water mass movements through direct measurement of circulation, density fields, ice conditions and modeling.

Roughly 30 stations were occupied in the region for two consecutive summer field seasons (2012 and 2013), including 7-9 stations along the Distributed Biological Observatory (DBO) line. Once data have been collected, analyzed, and quality controlled, maps and other data products will be made publicly available on this website and submitted to the NODC for permanent archiving and access.

Financial support for the research was provided by the US Bureau of Ocean Energy Management.