Cinkovich, A. M.. Dauphin Island Sea Lab, acinko@aol.com
Graham, W. M.. Dauphin Island Sea Lab, mgraham@jaguar1.usouthal.edu

 
OBSERVATIONS OF JELLYFISH AROUND DENSITY DISCONTINUITIES USING AN IN SITU VIDEO PROFILER
 
Density discontinuities occurring as both surface fronts and pycnoclines are often regions of intense biological activity. Still, there is relatively little observational data that characterizes the nature of how animals - especially zooplankton - are distributed in and around these features. Using in situ videography from an integrated profiling CTD-video system, we present some of the first data describing the fine-scale distribution of megaplankton (primarily ctenophores and medusae) around density discontinuities. While sharp fronts and pycnoclines serve as sites for increased jellyfish abundance, they also act as distributional boundaries between predator (medusa Chrysaora quinquecirrha) and prey (ctenophore Mnemiopsis spp.) species at scales of a few meters. The in situ methodology described here is also useful for considering mechanisms by which animals interact with discontinuities, and we provide evidence that shear stresses at discontinuities are likely important to induce a behavioral response. Discontinuities likely contribute to increased reproductive success of jellyfish by facilitating gamete transfer between individuals.
 
Day: Thursday, Feb. 4
Time: Poster
Location: Sweeney Center
 
Code: SS04TH0060S