Centimeter scale vertical heterogeneity in bacteria and chlorophyll a

Publisher Website
Google Scholar
Abstract
The vertical distribution of bacterial abundance and chlorophyll a was examined at the centimeter scale with a high resolution sampler and the variation at this scale compared to the variation across the entire water column. Samples were taken near the mouth of Chesapeake Bay, USA, in the coastal Atlantic environment as part of the MECCAS (Microbial Exchanges and Couplings in Coastal Atlantic Systems) program. Bacterial abundance changed up to 5.1 times over the entire water column, while changing up to 3.5 times over 10 cm. Chlorophyll a concentration changed up to 8 times over the entire water column and 5.1 times across the sampler. The high resolution of the sampler revealed steep gradients of bacterial abudance and chlorophylla a. Bacterial abundance changed up to 35 times m-1, while the water column change was up to 2.1 times m-1. Chlorophyll a changed up to 45 times m-1, while the water column changes were less than 2 times m-1. These changes and gradients over small scales indicate that at least under some conditions there are ''small''-scale processes occurring that may be important to plankton ecology, as has been suggested by some theoretical studies.