Brink, L. A.. University of Maryland, lbrink@hpl.umces.edu
Kiladis, M. A.. University of Maryland, mkiladis@hpl.umces.edu
Purcell, J. E.. University of Maryland, purcell@hpl.umces.edu

 
EFFECT OF THE HYDRAULIC CONTROL POINT ON EGG PRODUCTION AND FEEDING BY THE CTENOPHORE, MNEMIOPSIS LEIDYI, IN CHESAPEAKE BAY
 
The hydraulic control point (HCPt) is a ubiquitous feature of the mid-Chesapeake Bay where physical characteristics change due to a deepening of the channel. The result is a fairly well-mixed water column at the sill, with a deepening of the pycnocline. It was initially believed that the HCPt would be an area of high biological production, but this may not be the case. Egg production and gut contents of the ctenophore Mnemiopsis leidyi were measured both within and outside of the HCPt during April and August, 1998. Data from April indicate that ctenophores collected within the HCPt produced nearly 93% fewer eggs than those individuals collected outside this area. Gut content analysis revealed that over 43% of ctenophores collected within the HCPt had no prey items in their guts, as compared to less than 20% of ctenophores collected elsewhere in the bay. Despite lower fecundity and fewer gut contents found within the HCPt, ctenophore densities were generally higher there in both April and August. Zooplankton concentrations throughout the bay are also being looked at as a possible means of explaining the large disparity in egg production by ctenophores collected within and outside of this region.
 
Day: Thursday, Feb. 4
Time: 09:45 - 10:00am
Location: Hilton of Santa Fe
 
Code: SS04TH0945H