Thesis (Ph.D.)--University of Washington. / Vita. Bibliography: L. 122-128.

A series of modern sediment samples from seven sites and five sediment cores collected in central and southern Biscayne Bay were analyzed for benthic foraminifers. The goal of the research was to determine important foraminiferal assemblages in the modern environment, and use these data to assess the distributions of marine ecosystems over the past 100-400 years. Two of the cores are from localities in the mid-bay, whereas three represent near-shore sites. The latter cores were collected under the supposition that near-shore sites may be more sensitive to recent ecosystem change that may not be so readily apparent at the mid-bay sites. Seven assemblages were identified from these data that appear robust enough to be recognized at the regional level in Biscayne Bay. The assemblages identify a range of haline environments in Biscayne Bay both presently and in the recent past. None of the assemblages is typical of a continental shelf assemblage after Rose and Lidz (1977), but the conditions within Biscayne Bay include assemblages indicative of polyhaline-euhaline restricted circulation environments and mesohaline brackish environments. The near-shore cores reveal a pattern of assemblages indicative of increasing salinity. There is clearly a natural component of the ongoing Holocene marine transgression. However, there are key data which show sudden increases in salinity via rapid changes to the benthic foraminiferal assemblages. At Middle Key, salinity increases at the time of construction of the Key West Extension of the Florida East Coast Railway. Increased marine species at the top of the core corroborate the findings of Ishman et al. (1998) from a core in Manatee Bay. The foraminiferal assemblages near the top of the cores at Black Point North and at Chicken Key show a shift toward higher salinity conditions. Ostracode and mollusk data in Wingard et al. (2004) reveal an increase of genera that are tolerant of wide ranges of salinity. This manner of salinity fluctuations is not correlative to any patterns observed historically in any of the cores from Biscayne Bay. Recent changes to the marine ecosystems in Biscayne Bay reflect both natural and anthropogenic changes. It is necessary to determine appropriate restoration of natural sheet and groundwater flows to Biscayne Bay as part of the ongoing Everglades restoration to reduce the high stress of salinity fluctuations that are a recent alteration to the natural ecosystems in Biscayne Bay.

The spatial and temporal distribution of modern diatom assemblages in surface sediments, on the most dominant macrophytes, and in the water column at 96 locations in Florida Bay, Biscayne Bay and adjacent regions were examined in order to develop paleoenvironmental prediction models for this region. Analyses of these distributions revealed distinct temporal and spatial differences in assemblages among the locations. The differences among diatom assemblages living on subaquatic vegetation and sediments, and in the water column were significant. Because concentrations of salts, total phosphorus (WTP), total nitrogen (WTN) and total organic carbon (WTOC) are partly controlled by water management in this region, diatom-based models were produced to assess these variables. Discriminant function analyses showed that diatoms can also be successfully used to reconstruct changes in the abundance of diatom assemblages typical for different habitats and life habits. To interpret paleoenvironmental changes, changes in salinity, WTN, WTP and WTOC were inferred from diatoms preserved in sediment cores collected along environmental gradients in Florida Bay (4 cores) and from nearshore and offshore locations in Biscayne Bay (3 cores). The reconstructions showed that water quality conditions in these estuaries have been fluctuating for thousands of years due to natural processes and sea-level changes, but almost synchronized shifts in diatom assemblages occurred in the mid-1960’s at all coring locations (except Ninemile Bank and Bob Allen Bank in Florida Bay). These alterations correspond to the major construction of numerous water management structures on the mainland. Additionally, all the coring sites (except Card Sound Bank, Biscayne Bay and Trout Cove, Florida Bay) showed decreasing salinity and fluctuations in nutrient levels in the last two decades that correspond to increased rainfall in the 1990’s and increased freshwater discharge to the bays, a result of increased freshwater deliveries to the Everglades by South Florida Water Management District in the 1980’s and 1990’s. Reconstructions of the abundance of diatom assemblages typical for different habitats and life habits revealed multiple sources of diatoms to the coring locations and that epiphytic assemblages in both bays increased in abundance since the early 1990’s.

Introduced species present one of the greatest threats to biodiversity of native species, and knowledge of introduced species ecology is imperative for the development of management plans to ensure conservation of native species populations. We sought to determine the distribution and nesting behavior of an introduced population of red-bellied squirrels (Sciurus aureogaster) on islands of the Florida Keys currently managed as part of Biscayne National Park, and document potential for the species to impact native flora and fauna. Squirrels were difficult to observe in the dense vegetation of the subtropical forest, so we relied on their leaf nests, which were highly visible in the canopy of trees, to determine current presence and distribution on the Park's islands. We found nests throughout the mixed-hardwood forests of Elliott Key and Sands Key, and also documented a single, old nest on Old Rhodes Key, the first ever documentation of the species that far south in the Upper Keys. Nests were located in tall trees with more canopy linkages than random focal trees, and nests were placed in the upper canopy on the north side of the nest tree more often than expected by chance. Squirrels selected West Indies mahogany (Swietenia mahagoni) to place nests more often than available in the forest. Squirrels used areas with greater tree density and canopy cover, but lower recent hurricane damage and fewer woody shrub stems, than areas available at random in the forest. Squirrels built nests only in mixed-hardwood forest. Overall, this introduced species exhibited nest site selection behavior similar to other tree squirrels, and appears capable of continued spread despite the initial site of introduction on an oceanic island. Knowledge obtained from this research is being used by managers and applied to an eradication program to remove this invasive species from Biscayne National Park.

Two experiments were performed to determine the effect of ocean acidification on Montastraea faveolata vertical skeletal growth and lesion healing. The first experiment used three different CO2 concentrations: present day atmospheric pCO2, 380 microatm, and the atmospheric pCO2 expected by the years 2050, 560 microatm, and 2100, 800 microatm. The second experiment used 380 and 560 microatm. In the second experiment where the influence of parent colony was analyzed, M. faveolata fragments from one coral colony had significantly slower skeletal growth rates and less healed lesion area than other colonies. Corals that calcify and regenerate tissue slower may have less resilience to ocean acidification. The experiments demonstrated that the corals in 800 microatm grew significantly slower than corals in 380 or 560 microatm. Increased CO2 concentrations increased M. faveolata skeletal growth rates and healed lesion area until a threshold was reached, 560 microatm, then growth rates and healed lesion area decreased. Less than 1% of the variability in healing rates could be explained by CO2. The Nature Conservancy Resilience Model was used as a framework to identify current management strategies of wider Caribbean MPAs that may increase coral reef resilience to climate change. Seven out of the 8 MPAs had representation, critical areas, connectivity, and effective management as determined by each MPA's management plan. Three management plans had specific climate management strategies. Each management plan had actions to build coral reef resilience, but institutional incapacities and other barriers can decrease the ability to increase reef resilience. Because of the weaknesses of the Resilience Model, revised resilience guidelines were developed with the Florida Keys National Marine Sanctuary (FKNMS) as a case study. The coral lesion experiment results and interviews with FKNMS managers and the FKNMS's Sanctuary Advisory Council helped design the revised resilience guidelines. The revised climate-based coral reef resilience guidelines are to 1) incorporate more no-take zones and hedge the risks against ocean acidification, 2) identify resilient coral reefs and perform more climate change research, 3) reduce local stressors, 4) enhance coral reef recovery, and 5) increase public awareness and education on climate change impacts to coral reefs.

The Along-Track Reef-Imaging System (ATRIS) is a vessel-mounted, digital camera, depth sounder and Global Positioning System (GPS) package that facilitates the rapid capture of underwater images in shallow-water benthic environments. This technology has the potential to collect ecologically significant data, particularly in benthic habitats less than 10 m in depth, with better location referencing and in less time than is required for surveys carried out by Scuba divers. In October 2004, ATRIS was tested coincidently with SCUBA-assisted video along transects on five patch reefs in Biscayne National Park. Images from both data sets were subsampled, viewed, and benthic cover under random points were identified and counted. Digital-still images of reef benthos collected by ATRIS were of higher quality than SCUBA-acquired video imagery, allowing more reliable classification of benthos. “Substrate”, which included areas of hard-ground, sand or rubble, was the most frequently identified benthic category (43%), followed by octocoral (21%), unidentifiable (19%), and macroalgae (12%). Total stony coral cover averaged less than 5%. ATRIS-acquired benthic-cover data were compared with rugosity data derived from the Experimental Advanced Airborne Research Lidar (EAARL), revealing no strong correlations, probably because much of the hard substrate patch reef topography was created by corals that have died in the past few decades. ATRIS, diver-acquired data, and EAARL provide different scales of information, all of which can be valuable tools for assessing and managing coral reefs.

Thesis (D.Min.)--Southwestern Baptist Theological Seminary, 2006. / Includes prospectus. Includes bibliographical references (leaves 165-177).

Thesis (D. Min.)--Southwestern Baptist Theological Seminary, 2006. / Abstract. Includes bibliographical references (leaves 165-177).

Shallow seagrass ecosystems frequently experience physical disturbance from vessel groundings. Specific restoration methods that modify physical, chemical, and biological aspects of disturbances are used to accelerate recovery. This study evaluated loss and recovery of ecosystem structure in disturbed seagrass meadows through plant and soil properties used as proxies for primary and secondary production, habitat quality, benthic metabolism, remineralization, and nutrient storage and exchange. The efficacy of common seagrass restoration techniques in accelerating recovery was also assessed. Beyond removal of macrophyte biomass, disturbance to seagrass sediments resulted in loss of organic matter and stored nutrients, and altered microbial and infaunal communities. Evidence of the effectiveness of restoration actions was variable. Fill placement prevented additional erosion, but the resulting sediment matrix had different physical properties, low organic matter content and nutrient pools, reduced benthic metabolism, and less primary and secondary production relative to the undisturbed ecosystem. Fertilization was effective in increasing nitrogen and phosphorus availability in the sediments, but concurrent enhancement of seagrass production was not detected. Seagrass herbivores removed substantial seagrass biomass via direct grazing, suggesting that leaf loss to seagrass herbivores is a spatially variable but critically important determinant of seagrass transplanting success. Convergence of plant and sediment response variables with levels in undisturbed seagrass meadows was not detected via natural recovery of disturbed sites, or through filling and fertilizing restoration sites. However, several indicators of ecosystem development related to primary production and nutrient accumulation suggest that early stages of ecosystem development have begun at these sites. This research suggests that vessel grounding disturbances in seagrass ecosystems create more complex and persistent resource losses than previously understood by resource managers. While the mechanics of implementing common seagrass restoration actions have been successfully developed by the restoration community, expectations of consistent or rapid recovery trajectories following restoration remain elusive.

Continuous and reliable monitoring of contaminants in drinking water, which adversely affect human health, is the main goal of the Broward County Well Field Protection Program. In this study the individual monitoring station locations were used in a yearly and quarterly spatiotemporal Ordinary Kriging interpolation to create a raster network of contaminant detections. In the final analysis, the raster spatiotemporal nitrate concentration trends were overlaid with a pollution vulnerability index to determine if the concentrations are influenced by a set of independent variables. The pollution vulnerability factors are depth to water, recharge, aquifer media, soil, impact to vadose zone, and conductivity. The creation of the nitrate raster dataset had an average RMS Standardized error close to 1 at 0.98. The greatest frequency of detections and the highest concentrations are found in the months of April, May, June, July, August, and September. An average of 76.4% of the nitrate intersected with cells of the pollution vulnerability index over 100.