Millan-Nunez, R. Facultad de Ciencias Marinas, UABC, millan@cicese.mx
Trees, C. Center for Hydro-Optics & Remote Sensing/SDSU, ctrees@chors.sdsu.edu
Barlow, R. Sea Fisheries Research Institute, rgbarlow@sfri.wcape.gov.za
Gibb, S. Plymouth Marine Laboratory, s.gibb@pml.ac.uk
Aiken, J. Plymouth Marine Laboratory, j.aiken@pml.ac.uk

 
PIGMENT SPECIFIC DISTRIBUTION AND COMMUNITY STRUCTURE OF PHYTOPLANKTON DURING NORTH AND SOUTH ATLANTIC TRANSECTS
 
Pigment samples were collected for HPLC analysis during Atlantic Meridional Transect cruises from the United Kingdom to the Falkland Islands. The primary objective was to investigate bio-optical processes in the Atlantic Ocean over broad spatial scales. Pigment samples were collected every two hours from a continuous underway system and from daily CTD stations. The concentration of divinyl chlorophyll a was elevated in the tropical and subtropical areas, indicating that prochlorophytes contributed to up 50 % of the total chlorophyll a biomass. The ubiquitous nature of cyanobacteria was also demonstrated using the ratio of zeaxanthin to total carotenoid concentration. Using published zeaxanthin to divinyl and monovinyl chlorophyll a ratios, it was estimated that cyanobacteria made up 30-40 % of the chlorophyll a in these tropical waters. The latitudinal and vertical distribution of photoprotectant (PPC) and photosynthetic (PSC) carotenoids were quiet dramatic. High PPC to total carotenoid ratios were found in the tropical and subtropical surface waters, but decrease with depth. The ratio of PPC to total carotenoids was a function on the photoadative state of the phytoplankton. The change in this ratio for both near surface and vertical samples as function of radiant flux will be discussed.
 
Day: Thursday, Feb. 4
Time: 04:15 - 04:30pm
Location: Sweeney Center
 
Code: SS36TH0415S