Phytoplankton Patchiness and Productivity: Implications for our Understanding of Marine Food Web Function and Dynamics.


Chief Scientist(s):

Susanne Menden-Deuer


Narragansett Bay to Georges Bank

Expedition Dates:

April 4, 2011 – April 11, 2011

The goal of this cruise was to understand how the distribution of phytoplankton, whether patchy or well mixed affects the productivity, and thus the export of C and energy from the system. Fostering a better understanding of phytoplankton dynamics will serve to increase our local expertise and abilities to understand ecological dynamics in Narragansett Bay in the future.

During EN490, we tested hypotheses about the importance of phytoplankton distribution to zooplankton predation and overall primary productivity in the ocean. The cruise progressed exactly as proposed. In total 8 graduate students (GSO/URI) and 4 undergraduate (URI) students gained valuable at sea experience. Students in Drs. Rynearson and Maranda’s lab fulfilled their cruise requirement and conducted some of their thesis work. Erica Killian, a Rhode Island high-school mathematics teacher participated within the ‘Teacher at Sea’ program. In addition to the proposed work, Dr. Chris Roman, URI/GSO joined the cruise with his graduate student to test a new float under development. After an initial departure delay, we first occupied 2 stations in Cape Cod Bay and spent the remainder transiting across the northern edge of Georges Bank (see Fig. 1). In total, 30 stations were occupied and the following samples collected: dissolved macronutrient and chlorophyll a concentrations, plankton particle size spectrum and physiology, genetic composition of plankton, isolation of target species, zooplankton grazing rates and vertical water column profiles. All station coordinates, types of samples collected and sampling depths are given in Table 1. The objectives of the cruise were met in that we were able to observe phytoplankton growth within the physical and chemical context it occurred in and had several tests of the float.