Bering Ecosystem Study (BEST)

 
 

Centered on the ice-impacted region of the eastern Bering Sea, the BEST program seeks to understand how variations in ice will impact the valuable fisheries and huge stocks of birds and marine mammals.  My role in this large program centers on the role that ice plays in determining the nutrient content of the shelf waters and how this impacts phytoplankton productivity and in turn, the other components of the food web.  I am also working on how the production and respiration processes on this broad shelf influence the chemistry of Arctic waters and the role that high latitude systems play in modifying waters at lower latitudes.

 

Introduction and overview

Ice cover in the eastern Bering in March 2007 (left).  Yellow line indicates approximate extent of ice.  Black line shows track of icebreaker Healy (below) during BEST sampling.

Ice dictates the development of phytoplankton growth.  Early in the year, continuous ice cover keeps productivity in the water low, although ice-algae may be active at this time (left).  As ice breaks up and melts, phytoplaknton growth increases (center and right panels).  The community of phytoplankton in the ice is unique to this environment.

The tremendous biological productivity at the ice edge appears to be the result of the mixture of just the right nutrient and light conditions. The colors below represent the concentrations of nitrate that comes mainly from deeper water.  Sea ice supplies fresh water to stabilize the surface layer and also, likely supplies iron, a key ingredient for growth.