Year

2021

Season

Spring

Paper Type

Master's Thesis

College

College of Arts and Sciences

Degree Name

Master of Science in Biology (MS)

Department

Biology

NACO controlled Corporate Body

University of North Florida. Department of Biology

First Advisor

Dr. Jim Gelsleichter

Second Advisor

Dr. Bryan Franks

Rights Statement

http://rightsstatements.org/vocab/InC/1.0/

Third Advisor

Dr. Adam Rosenblatt

Abstract

The scalloped hammerhead shark (Sphyrna lewini) worldwide population has been in sharp decline, and they are currently listed as a globally critically endangered species by the IUCN. This warrants a need to identify and protect critical habitats for the species, such as nurseries, which promote stable populations. A section of the Tolomato River, in northeastern Florida, has shown to host large and consistent numbers of young of year scalloped hammerhead sharks. This gave cause to determine whether this portion of the Atlantic Intracoastal Waterway (ICW) serves as a nursery habitat for the species and to understand how the sharks used the area. To declare the Tolomato River as a nursery habitat, three criteria needed to be met: the species were more commonly found in the Tolomato River as opposed to other sites, individual sharks stayed in the area for long periods of time (weeks or months), and the species used the habitat repeatedly across years. To address these criteria, a catch composition analysis, habitat preference study, mark-recapture analysis, and acoustic tracking were conducted. The results from these studies indicated that scalloped hammerhead neonates have a preference for the Tolomato River compared to other nearby estuaries. They additionally showed that individual scalloped hammerhead sharks are using the habitat for extended periods of time and the species utilizes the Tolomato River annually. These results indicate that the Tolomato River serves as a nursery habitat for the scalloped hammerhead shark. Due to the established importance of nursery habitats to the welfare of shark populations, the identification of nurseries is often required in various management plans. Thus, data from this project contributes to the management of the scalloped hammerhead shark, a species in need of protection.

Available for download on Wednesday, April 20, 2022

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