Temperature Regulation of
Bacterial Activity During the Spring Bloom in Newfoundland Coastal
Waters
LAWRENCE R. POMEROY AND DON DEIBEL
While the spring
phytoplankton bloom in Newfoundland coastal waters is in progress
during April and May, at water temperatures between -1º and
+ 2º C,
bacterial growth and respiratory rates remain low. Microbial community
respiration is not measurable at -0.2º
C. Particulate materials
that would be utilized by microorganisms in 2 to 3 days at 20º to
25º
C require 11 days at 4º C and 18 days at -0.2º C.
Thus, photosynthesis is active but microbial utilization of the
products is suppressed. High secondary production in cold water
may result from the low rate of microbial decomposition, enabling
herbivores to utilize much of the primary production.