Theses and Dissertations

Copyright Statement

All rights reserved. This publication is intended for use solely by faculty, students, and staff of Nova Southeastern University. No part of this publication may be reproduced, distributed, or transmitted in any form or by any means, now known or later developed, including but not limited to photocopying, recording, or other electronic or mechanical methods, without the prior written permission of the author or the publisher.

Defense Date

6-2007

Document Type

Thesis - NSU Access Only

Degree Name

M.S. Marine Biology

Second Degree Name

M.S. Coastal Zone Management

Department

Oceanographic Center

First Advisor

Curtis M. Burney

Second Advisor

Lou Fisher

Third Advisor

Keith Ronald

Abstract

Many environmental parameters, both physical and anthropogenic, can influence nest site selection. One of the most basic requirements for a suitable nesting habitat is a dark beach. With the increases in coastal development, the beaches of Broward County, Florida are becoming more polluted by artificial light, making dark beaches a rarity. On urban beaches in Boca Raton, Florida, it was found that turtles nested directly in front of tall structures, such as high-rise condominiums and clusters of Australian pine trees (Casuarina equisetifolia), that blocked the sky glow from the city providing darker sections of the beach more suitable to nesting females (Salmon et al., 1995). The goal of this project was to compare the previous four years (2002-2005) of nesting with the heights of the buildings and the sky brightness, in historically high nesting zones of Broward County (Mattison, 2004). Nesting distributions were plotted using GIS (Global Information Systems), and the beach was subdivided into smaller sections according to the buildings in each section. The number of nests in front of a building, in front of a gap between the buildings, and in residential zones were compared. The average nesting density (nests/10m) over all four years, as well as the individual yearly densities were analyzed. Ecological light pollution (sky brightness) was measured in nine different directions and angles. The brightest direction for all three locations was when the meter was pointed directly at the structures and the gaps between them at an elevation of 40° (Building and Gap 40°). There was no evidence of higher light intensities from sky glow above the buildings at an angle of 65o (Building and Gap 65°). There was a difference in sky brightness among the three zones, with the tall buildings and gaps being consistently brighter than the residential zones. Contrary to expectations, the gaps were not brighter than the buildings, and there was no significant relationship between sky brightness and nesting densities (Spearman rank correlation). There was also no relationship between the nesting densities and the heights of the buildings (Spearman rank correlation). There was also no association among nesting density, sky brightness, and height (Kendall’s coefficient concordance). These results are contradictory to the theory that suggests females nest more in front of buildings where the sky brightness is blocked (Salmon et al., 1995). This may be due to the fact the buildings and residences were not incompliance with lighting ordinances, causing very high light levels, or it could be caused by the close spacing of the buildings, which resulted in similar light intensities in front of buildings and gaps. These results could provide valuable insight into appropriate management of light pollution and conservation efforts for sea turtles nesting in Broward County.

Comments

Funding provided by Broward County Environmental Protection Department.

To access this thesis/dissertation you must have a valid nova.edu OR mynsu.nova.edu email address and create an account for NSUWorks.

Free My Thesis

If you are the author of this work and would like to grant permission to make it openly accessible to all, please click the Free My Thesis button.

  Link to NovaCat

Share

COinS