Van Mooy KN207-01

Ship

Cruise Party

Departure: Apr 21, 2012

Arrival: May 4, 2012

Operations Area

Science Objectives

Intact polar diacyglycerols (IP-DAGs) are the fatty-acid bearing lipid molecules that compose bacterial and eukaryotic cell membranes.  As such, they are one of the most abundant classes of lipid molecules in plankton, and play a major role in the marine carbon cycle.  However, until very recently, the molecular diversity of IP-DAGs was poorly understood; the structural identity and characteristics of IP-DAGs were inferred almost exclusively from their constituent fatty acids.  Led by advances in high performance liquid chromatography/mass spectrometry (HPLC/MS) methods, we have established that the IP-DAGs in the upper ocean are dominated by sulfolipids and betaine lipids.  These non-phosphorus containing IP-DAGs were largely unknown to chemical oceanography.  In contrast, phospholipids, which have been the focus of considerable research, compose a disproportionally small fraction of total IP-DAGs.  Over the last three years we have made some progress in understanding the planktonic origins of non-phosphorus IP-DAGs and have identified the possibility that sulfolipids and betaine lipids are substituted for phospholipids by phytoplankton when dissolved phosphate becomes scarce.  But we still lack even a cursory understanding of biochemical functions and geochemical fates of non-phosphorus IP-DAGs.  Given that these molecules are among the most abundant lipid molecules on the planet, this represents a profound and unexpected gap in our understanding the marine carbon and phosphorus cycles.  In this proposal we outline a research plan to begin to rectify this situation.  Specifically, we will ask:

•  How do non-phosphorus lipids contribute to variations in the C:N:P of particulate organic matter in the Sargasso Sea?

•  What are the relative degradation rates of phospholipids and non-phosphorus lipids in surface waters?

•  Which groups of microbes utilize the carbon and phosphorus from different IP-DAGs?

 • What are the relative contributions of different IP-DAGs to particulate organic matter export to the deep-sea?

Science Activities

Additional Info

Stations:

Supporting documentation:

Shipboard Equipment

Shipboard Communication

CTD/Water Sampling

Critical CTD Sensors

Hydrographic Analysis Equipment

MET Sensors

Sample Storage

Navigation

Navigation

Winches

Wire use and application

Standard Oceanographic Cables

Portable Vans

Checklist

BERMUDA:

Office: (508)-289-3811
Mobile: (617)-999-4163
Email: csmith@whoi.edu

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