Conservation

Commercial longline fishing results in large amounts of incidental bycatch of elasmobranch fishes (sharks, skates, and rays). Teleost species lack electrosensory systems and development of technologies which target the ampullary organs of sharks provides an avenue to selectively deter elasmobranchs without affecting the catch rate of target teleosts. Electric field measurements and a controlled scientific longline study were conducted testing whether the lanthanide metal neodymium or zinc/graphite might reduce elasmobranch catch per unit effort (CPUE). Baited longline hooks were treated with neodymium and zinc/graphite and catch rates were compared to that of controls. Shark CPUE decreased by 60% on neodymium treated hooks and 80% on zinc/graphite treated hooks. The effectiveness of both treatments varied among species with significant reductions shown for Atlantic sharpnose sharks (Rhizoprionodon terranovae) but less dramatic differences for others. Zinc/graphite is potentially a viable tool for reduction of shark bycatch in a commercial longline fishery.

In examining the intentional relationship between the conservationist and the shark in South Florida, this thesis considers the latter as both a scarce natural resource - caught up in what Clifford Geertz citing Weber referred to as "webs of significance" (Geertz 1973:5) - and as a reflection of dynamic human conceptions of nature : a meta shark. This complex relationship is described by interpretations of conservation discourse recorded through ethnographic interviews that demonstrate how these perceptions have been influenced by factors such as personal experiences, film and text, and broad changes in the relationship between humans and nature since the early days of the environmental movement. By linking these perceptual changes with changes in American shark conservation policy, this work not only explains a relationship between culture, perception, and policy, but also celebrates the emergence of a multispecies marine community.

The presence of heavy metals and other pollutants is detrimental to marine ecosystems. The queen conch, once an important fisheries species in the Florida Keys, has not sufficiently recovered after a 25-year fishery closure. Research has shown high levels of copper and zinc in the gonads and digestive glands of adult conch found in the nearshore waters. Four sites relevant to queen conch larval recruitment were tested in 2010 for the presence of copper and zinc in the water, phytoplankton, sediment, and seagrass epiphytes over seven months. Both metals were detected in all sample types and no seasonal or geographical differences were detected. Surface water concentrations from the field were used to conduct acute and chronic toxicity tests on various ages of queen conch larvae and their phytoplankton food source. When zinc concentrations (0-40 (So(Bg/L) similar to those measured in situ were used, there was no significant impact on conch larval survival although some velar lobe de velopment was impaired. However, field concentrations of copper (0-15 (So(Bg/L), which often surpassed water quality standards, negatively impacted growth, survival, and development of the larvae. Chronic exposure to copper, through the water and food, disrupted the metamorphic success of competent larvae and decreased post-metamorphosis survival. Exposure to copper at later life stages increased mortality, suggesting that heavy metals have a negative effect on larval recruitment in localized areas of the Florida Keys. Structural equation modeling revealed that copper and zinc are moving through the systems differently and are best represented by two different models.

The commercially important queen conch, Strombus gigas, has been observed copulating with multiple partners and laying multiple egg masses during a reproductive season (Randall, 1964). While multiple paternity has been confirmed using microsatellite based genetic analysis for a variety of other gastropods, this technique has not been employed for S. gigas. Determining whether or not this species is capable of multiple paternity is important to understanding and maintaining genetic diversity of natural and captive populations. While an assessment of multiple paternity is the ultimate goal of this study, for my thesis, I have completed preliminary work which includes perfecting methods of tissue collection, DNA extraction, and DNA amplification with six non-labeled polymorphic microsatellite molecular markers, using cultured Strombus gigas animals. In addition, I collected tissue and extracted DNA from three wild S. gigas adult females and their egg masses from Pelican Shoal in the Florida Keys.

Prior to 2000, very little was known about fish biodiversity on the New England Seamount chain. In late 2000, 115 fish species were found on Bear Seamount by the NOAA R/V "Delaware II." Woods Hole Oceanographic Institution conducted two cruises to explore the New England Seamount chain in 2003. This study assessed fish species throughout Alvin submersible dives during these 2003 cruises. Digital video footage was converted to still photographs and video clips using the Macintosh movie program iMovie. Fishes were identified to the lowest possible taxonomic level using keys and literature. The habitat, depth and behavior of observed fishes were compared to the literature available. Geographical distributions of the species were considered. I assessed substrate preference by building a chart that reflects the different sediment regimes that fishes were found on. In all I identified 317 individuals representing 33 different taxa, including two species with new habitat range information Neocyttus helgae and Lepidion sp.

The construction of Abacoa included an attempt to conserve the wildlife in a Greenway, a set of habitats separated from the residential and commercial areas. All of the wetlandswith in Abacoa represent artificially constructed ponds, canals, and streams first created from 1998-2004. The present study focuses on the anuran (i.e., frog and toad) populations and looks at the number of different species that have naturally colonized six differnet sites around Abacoa. Each of these sites varies in qualities that may affect the probability of breeding in that section. The quality of water is known to be less ideal as the water flows away from the headwaters and mixes with water from other sources. This study aims to determine which anuran species are found at each of these sites after nearly a decade of colonization, and how both anuran diversity and abundance correlates with water and habitat quality.

This study assesses the philosophical underpinnings of endangered species protections focused on gopher tortoises in Florida. From 1993-2007, gopher tortoises (Gopherus polyphemus) were listed in Florida as a species of special concern. Land developers wanting to build on their habitats could apply for an incidental take permit, paying a fee that allowed tortoises to be 'entombed' in their burrows to die a slow death. In 2007, when gopher tortoise status was up-losted to 'threatened', a new policy ended the incidental take permit program. This study compares policy guidelines of the 1991 and 2007 gopher tortoise management plans and explores cases that deal with incidental take controversies. I will apply perspectives from environmental philosophy to my analysis to understand how policies attempt to balance economic goals with a mandate to protect species in peril.