Date of Award

1-2012

Document Type

Thesis

Degree Name

Master of Science (MS)

College/School

College of Science and Mathematics

Department/Program

Biology

Thesis Sponsor/Dissertation Chair/Project Chair

Paul Bologna

Committee Member

Meiyin Wu

Committee Member

John Gaynor

Abstract

Sea nettles (Chrysaora quinquecirrha) have become abundant in the estuaries of the Mid- Atlantic States. Their ample numbers are an indicator of a disturbed ecosystem. Various factors have been attributed to the rise in numbers of sea nettles including eutrophication, overfishing, global warming, construction and species introduction. Bamegat Bay is a highly eutrophic system with excess nitrogen and organic carbon arriving in the bay via runoff and watershed waste inputs. Many commercial fisheries in Bamegat Bay have ceased to exist and the remaining fisheries are dwindling. An overabundance of medusae and polyps will further impact fisheries since jellyfish compete with larval fish when young and prey on planktonic eggs and larvae as they mature.

While observations of the medusa stage indicate a disproportionate abundance in the northern part of the bay, quantification of these differences has not taken place. Information about the life history of the Chrysaora quinquecirrha polyp in the field is limited. This research focused on undertaking a settlement survey of polyps from eight sites in Bamegat Bay. Results showed initial settlement in July with continued settlement observed until November. Of the eight sites monitored monthly, only two sites showed settlement and both of these occurred in the northern portion of the bay. Peak settlement was seen at Cattus Island during August with 1,528 polyps collected from that settling plate. Water quality assessment indicated that these sites had lower salinities than all of the other sites except Toms River. Previous research in the Chesapeake Bay has established that Chrysaora quinquecirrha polyps are only found in waters of 5-20ppt salinity.

Polyp growth and strobilation will directly determine adult medusa populations. Therefore, the distributions of polyps and medusae are most likely linked and reflect differences in water quality. Other factors may also influence polyp populations including the other species found on the plates with the polyps. With continued research, a count of polyps could be used to predict future medusae populations. This study reports on the temporal and spatial patterns of polyp distribution in Bamegat Bay and the differences in physical characteristics and species composition at the sites where polyps were located.

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