Parrish, C. C. Memorial University of Newfoundland, cparrish@morgan.ucs.mun.ca
Thompson, R. J. Memorial University of Newfoundland, thompson@morgan.ucs.mun.ca
Deibel, D. Memorial University of Newfoundland, ddeibel@morgan.ucs.mun.ca

 
LIPID BIOGEOCHEMISTRY OF PLANKTON AND SETTLING MATTER DURING THE SPRING BLOOM IN A COLD OCEAN COASTAL ENVIRONMENT
 
Lipid classes and fatty acids were measured in plankton and settling particulate matter during the spring bloom in Conception Bay, Newfoundland, to determine the quantity and quality of material settling from the upper mixed layer into the benthic food web. Net-tow samples (20 um) and sediment trap samples (80 and 220 m) were taken in the deepest part of the bay (240 m) at about 16 day intervals from 27/3 - 9/7/96. Total lipid (TL) concentrations in plankton reached a maximum of 6.32.5% dry weight at the height of the bloom in April. Bacterial fatty acid markers were at their lowest during the bloom period (2.2-2.8% of total fatty acids), while polyunsaturated fatty acids (PUFA) were at their highest from the beginning of the bloom onwards (44-53%). The maximum fluxes of TL (0.07001 g/m2/d) in non-poisoned 80 m traps occurred at the bloom maximum while those at 220 m (0.040.002 g/m2/d) occurred 16 days later. In these deep traps, PUFA were maintained at high levels (34-35%) throughout the bloom period while bacterial markers were at their lowest (2.3-2.8%). These data indicate a rapid transfer of highly nutritious material to the benthos during the spring bloom in Conception Bay.
 
Day: Friday, Feb. 5
Time: 09:30 - 09:45am
Location: Sweeney Center
 
Code: CS55FR0930S