SIMULTANEOUS MEASUREMENTS OF SMALL-SCALE PHYSICAL DYNAMICS AND ZOOPLANKTON DISTRIBUTIONS

Haury et al., (Deep Sea Res., 37, 447-461, 1990) described how turbulence and vertical shear generated by the passage of a storm affected the vertical distributions and community structure of plankton in Monterey Bay, Ca. The data presented came from a larger set of five plankton recorder collections of zooplankton, taken together with temperature, salinity, turbulent kinetic energy dissipation rate, and vertical current shear data on the research submarine Dolphin. Here we report on the analysis of the whole data set, which represents a wide range of physical dynamic conditions. While the overall community structure remained relatively constant over the sampling period, the relationships between taxonomic categories and between categories and the physical dynamics were complex and variable; factors related to depth were the most important. During periods of weak winds (low kinetic energy conditions) some of the biological variability appeared to be related to the level of turbulent dissipation. Other relationships were not detected due to the limitations of the plankton sampler and its interactions with the highly variable biological and physical conditions. In view of these difficulties, we recommend that future field investigations of the relationships between physical parameters and zooplankton distributions make greater use of acoustic and other remote-sensing technologies, preferably in combination with numberical simulation studies to help guide and interpret the field work.