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Diet And Reproductive Biology Of The Blacknose Shark (Carcharhinus Acronotus) From The Southwestern Atlantic Ocean, Ryan Michael Ford

UNF Graduate Theses and Dissertations

The blacknose shark (Carcharhinus acronotus) is a common small coastal shark species found in nearshore waters along the southeast coast of the United States, from North Carolina into the Gulf of Mexico and extending further south into the Bahamas. There has been some debate in recent years over the reproductive periodicity of C. acronotus in waters off the U.S. coast. Earlier studies have suggested that Gulf C. acronotus reproduce on an annual basis whereas the Atlantic populations of this species may reproduce biennially. Additionally, there have been no known studies on the diet of C. acronotus. The goal of the …

Abundance, Distribution, And Habitat Use Of Sharks In Two Northeast Florida Estuaries, Michael Philip Mccallister

UNF Graduate Theses and Dissertations

Sharks are considered top predators in many marine ecosystems, and can play an important role in structuring those communities. As a result, it is necessary to understand the factors that influence their abundance and distribution. This is particularly important as fishery managers develop fishery management plans for sharks that identify areas that serve as essential fish habitat (EFH). This includes nursery habitat where sharks are born and juveniles spend the early part of their life. However, our understanding of shark habitat use in the northeast Florida waters is limited. The goal of this thesis was to characterize the abundance and …

The Influence Of Seawater And Sulfate Reduction On Phosphate Release From Tidal Wetland Soils In The St. John’S River, Florida, Asher Williams

UNF Graduate Theses and Dissertations

Climate change and increasing sea level elevation are predicted to increase salinity in estuarine tidal wetlands in the Southeastern United States. Since much of the ecosystem function in these areas is predicated upon salinity regimes, many fundamental changes are likely to occur as a result. The influence of salinity and SO4 2- reduction on PO4 3- release from tidal wetland soils was evaluated along a salinity gradient at three sites in The St. John’s River, Florida using both field and laboratorybased methods. Porewater was sampled over the course of 10 months to determine ambient levels of SO4 2- and PO4 …

Population Structure And Nest Success Of Gopher Tortoises (Gopherus Polyphemus), And Vegetative Response To Prescribed Burning In Northeast Florida, Kristine Constance Amatuli

UNF Graduate Theses and Dissertations

A gopher tortoise population on the campus of University of North Florida is part of an ongoing study initiated during the early 1990s, and this project presents data on this population collected during the 2009-2011 field seasons. The project has three major objectives: 1) measure population demographics including density and structure to assess long-term viability and recruitment, 2) evaluate decadal growth rates of individuals by comparing measurements of tortoises captured and marked in the 1990-1994 study done at the same site with those tortoises recaptured during the current study, and 3) assess the effect of prescribed burning on vegetation. In …

Demography And Reproductive Biology Of The Gopher Tortoise (Gopherus Polyphemus) Population At White Oak Plantation, Nassau County, Florida, Julia Rachel Smith

UNF Graduate Theses and Dissertations

The demography and reproductive biology of the gopher tortoise (Gopherus polyphemus) was studied for two years at White Oak Plantation (WOP), located in northeast Florida along the St. Mary’s river. Two sub‐populations were studied in regions I referred to as Site A and Site B. I located 312 burrows and captured 109 different tortoises, either by hand or using bucket traps. Tortoise density was 4.48/ha at Site A and only 1.15/ha at Site B. Juveniles were the most abundant age class overall, while hatchlings were numerous at Site A but virtually absent at Site B. The combined sex ratio for …

Nutrient Transport By Shrimp Hepatopancreas, Tamla A. Simmons

UNF Graduate Theses and Dissertations

Purified brush border membrane vesicles (BBMV) were isolated to characterize primary cellular transport mechanisms for white shrimp. The ultimate goal is to determine the effective components of a shrimp’s diet, thereby enhancing growth, as well as nutrient content. Juvenile shrimp are dependent on plant material as a food source. Potassium is a key component of plants, thus it may play a role in nutrient transport. In addition, divalent metals have been shown to act as co-transporters in several other organisms, thus they may serve as a transport mechanism for shrimp.

Fresh, live, white or brown shrimp were obtained, and from …