Impacts of Sea Ice on the Hydrographic Structure, Nutrients, and Mesozooplankton over the Eastern Bering Sea Shelf

Funds are provided to support a service proposal that will undertake extensive temperature, salinity, nutrient, and zooplankton observations on the Bering Sea shelf during the spring (2007) cruise on the Healy. The PIs specifically propose to do the following:

Collect hydrography (temperature, salinity, fluorescence, PAR, transmisometer data, oxygen) along the mutually agreed upon transects for the 2007 Healy cruise.

Collect water column samples for shipboard analysis of nutrients (nitrate, nitrite, silicate, phosphate, ammonia) at selected intervals at each oceanographic station and any samples provided by other BEST investigators (e.g. samples from productivity casts, grazing experiments, incubations, etc.). The selected depths are as follows: 10-m intervals to 50m, 25m intervals 50m-200m and on casts deeper than 200m at selected depths agreed to by investigators.

Collect cores on ice flows and sample them for nutrients, salinity, temperature, and chlorophyll.

Collect mesozooplankton samples in both the open waters and at stations within the ice. Samples will be collected at every second or third station on the transects and at every station at fronts.

Titrate oxygen for calibration of CTD O2 sensor.

Collect and freeze chlorophyll samples at selected locations and process them after the cruise in the PIs' laboratory.

Provide vertical shear estimates from the shipboard ADCP.

They will collect and quality control these physical and chemical data needed by BEST (the Bering Sea Ecosystem Study) investigators; map the physical and chemical structure over the Bering Sea shelf; make the all physical and chemical data available to all other investigators in a timely manner; and provide the interpretation and analysis of physical and chemical data.