Effects of Sand Characteristics and Inundation on the Hatching Success of Loggerhead Sea Turtle (Caretta caretta) Clutches on Low-Relief Mangrove Islands in Southwest Florida

Abstract

ABSTRACT We determined characteristics of the sand, level and frequency of tidal inundation, and hatching success at loggerhead sea turtle (Caretta caretta) nest sites on 8 low-relief mangrove islands in the northern half of the Ten Thousand Islands in southwest Florida. The sand was generally composed of larger particles and tended to be wetter, more porous, and more saline than on other loggerhead nesting beaches. More than one-third (38.9%) of the nest sites experienced tidal inundation. The mean salinity of inundating water was 26.9‰ (± 9.3, range = 0–40). The water content and salinity of the sand water at nest sites increased with increasing frequency of inundations. The mean particle diameter and total porosity of the sand were negatively related to sand water salinity, perhaps indicating that in the largest-grained, most porous sands, salt was more effectively washed out by rainfall. Hatching success decreased as inundations, sand water content, and sand water salinity increased. However, at nest ...