Deployment: OC413

Cruise Objective: The primary objective of the project is to examine the relationships
between growth rate, grazing mortality, and relative abundance for
two pico-phytoplankton groups (Prochlorococcus and Synechococcus) in
surface waters of the Sargasso Sea. On-board flow cytometry will be
used to assess the abundance of these phytoplankton. A suite of
experimental approaches for measuring growth and grazing mortality in
natural picoplankton populations will also be applied.

Science Activities: This work will involve both on-deck incubations and intensive water-
column sampling. For incubations, trace metal-clean Go-Flo samples
will be required (see Other Comments, below). For the water-column
measurements, CTD casts will be repeatedly made in the vicinity of a
free-drifting drogue (see Other Comments); drogue deployments will
last ~36 hr.

Operations Area: We plan to occupy 2 or 3 major stations, with 1 or 2 drogue
deployments and experimental series at each. Additional short
stations along the transect from WHOI to BATS will also be made.

Cruise information and original data are available from the NSF R2R data catalog.