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South Florida, United States, is an ideal place for conveniently studying modern carbonate environments and their fossil equivalents in close proximity. It is the only place where such field studies can be carried out with the excellent logistical support available in a major metropolitan area (Miami). Consequently, south Florida has been used extensively for training petroleum geologists as well as providing reef and quarry trips of short duration for geology classes. However, south Florida can also be used to study geomorphic features; biogenic and clastic sedimentology in fresh, brackish, and saline environments; and stratigraphie studies which correlate widely-spaced rock outcrops. In addition, many aspects of environmental geology, including groundwater, water pollution, ecological changes accompanying development, and the effects of hurricanes, can be studied here. This holistic approach was used in a 3 week laboratory and field course first offered in the summer of 1985. The area has been visited several times since then, and the places and features described in this paper are accurate as of February 2012. A uniformitarian approach was used, in which students studied rock outcrops and then examined the present-day depositional equivalent of each facies by snorkeling over modern reef tracts in the Florida Keys. Outcrops of Pleistocene rock units were examined from Miami southward through the Florida Keys. Students utilized the outcrop data, along with published data and their own observations of reef complexes, to make a regional stratigraphie synthesis and paleogeographic reconstruction for the study area. This article describes the course structure, field exercises, and logistics, which can serve as the basis for similar courses or site visits in this area in the future. Additional information is provided so instructors can tailor the course around their available time and financial limitations, anywhere from 3 days to 3 weeks. [ABSTRACT FROM AUTHOR]

This paper describes a methodology for modeling long-term evolution of multiple inlet systems in southwest and central Florida. The paper discusses the application of this methodology to two inlets within Sarasota Bay system in southwest Florida. The case studies of Longboat Pass and Venice Inlet demonstrate the importance of considering large temporal and spatial scales in multiple inlet systems. The results describe the evolution of Longboat Pass and Venice Inlet from 1880 to present. The analysis begins with natural conditions that existed before dredging or inlet modifications and investigates how inlet evolution can be influenced by navigation improvements or mining of ebb shoals for beach nourishment. [ABSTRACT FROM AUTHOR]

Wang, P.; Royer, E.L.; Jackson, K., and Gutierrez, S., 2024. Impacts of Hurricane Ian along the low-lying southwest Florida coast (USA) in 2022: Lessons learned. Journal of Coastal Research, 40(5), 827–851. Charlotte (North Carolina), ISSN 0749-0208. Hurricane Ian made landfall in the low-lying, densely populated, and developed southwestern Florida coast on 28 September 2022 as a large and slow-moving category 4 hurricane. Various U.S. federal and state agencies collected a large and comprehensive data set, including pre- and poststorm airborne LIDAR topography, in situ water level and wave measurements at numerous locations before, during, and after the storm, and poststorm high-water marks over a large area. This study reports results from a series of poststorm field investigations including ground observations of beach-dune erosion and deposition, catastrophic damage to various infrastructure, and widespread distribution of non-biodegradable materials washed into the estuary and numerous mangrove islands. Hurricane Ian induced large-scale inundation in low-lying southwest Florida, submerging all the barrier islands bordering Charlotte Harbor estuary, all the islands within the estuary, and up to 5 km into the mainland. Dense tree-type vegetation limited the landward penetration of beach-dune erosion and overwash deposition along the barrier islands. Net sand-volume loss from the beach-dune system ranged 10–25 m3/m and was controlled by the deep submergence of the system during the peak of the storm. The extremely high storm surge of up to 5.2 m above mean sea level generated by Hurricane Ian caused severe damage to the built environments over a large area. High storm waves superimposed on the elevated water level, reaching 1.2 m at the seaward edge of vegetated dunes, contributed to the destruction along the barrier islands. Hurricane Ian distributed a tremendous amount of non-biodegradable artificial debris over a large area and into sensitive natural environments, including numerous mangrove islands, barrier-island interior wetlands, and the estuary waterbody. Measures to prevent materials such as single-use plastics, insulation fibers, and household appliances from being washed into sensitive environments should be a significant part of prestorm preparation. [ABSTRACT FROM AUTHOR]

Cutler, E.M.; Albert, M.R., and White, K.D., 2019. A low-cost shoreline dynamic simulation model for proposed beach nourishment and dune construction: Introducing a new feasibility analysis tool. Journal of Coastal Research, 35(4), 907–919. Coconut Creek (Florida), ISSN 0749-0208. Beach nourishment and dune construction are common coastal risk-management strategies for shoreline erosion in the United States. Federal involvement with such projects relies on cost–benefit analyses, which in turn rely on life-cycle models of shoreline processes, such as the Army Corps of Engineers' Beach-fx event-driven physical and economic coastal model. However, use of these models can be computationally and data intensive. Costs associated with conducting a feasibility analysis for beach nourishment and dune construction may leave a community with few resources to explore other risk-management options. This paper, therefore, presents a first-order, screening-level, low-cost dynamic model that delivers results approximately comparable with those from life-cycle models. Applying the model to three locations in Florida shows that simulated nourishment intervals are within 5 years of those predicted by Beach-fx, leading to a similar number of nourishments over a 50-year project life span. A discussion on how one could apply the model to other areas is also included. It is intended that this model could serve as a first-pass screening tool for communities considering beach nourishment and dune construction before they decide to invest in the more thorough, but costly and data-intensive, life-cycle model simulations. [ABSTRACT FROM AUTHOR]

Huang, W.; Hagen, S., and Bacopoulos, P., 2014. Hydrodynamic modeling of Hurricane Dennis impact on estuarine salinity variation in Apalachicola Bay. Hurricane Dennis made landfall in Florida on 10 July 2005 and caused a storm surge of 2.4 m in Apalachicola. Field observations of salinity, winds, and river inflows are available at a few stations in the bay during the hurricane event. Presented in this paper is a numerical modeling study that investigates the effects of Hurricane Dennis on estuarine mixing and transport. A previously calibrated three-dimensional (3D) estuarine hydrodynamic model was further validated by the field observations of salinity and water levels during the hurricane event. A large-scale storm-surge model was used to provide storm-surge hydrographs at the five estuarine boundaries for the 3D estuarine model. This model integration proved successful with the results indicating that the model predictions of storm-surge hydrographs and salinity match well with observations. Model predictions of spatial distributions of salinity and current fields are presented to demonstrate the fresh-saline water mixing at different times of the storm-surge event. Results indicate that the hurricane-induced storm surge caused substantial increase of salinity in the bay. Majority saline water entered the bay from the east during the storm surge event. Salinity at the oyster reef, Cat Point in the eastern bay area, is more sensitive to the increased water levels caused by storm surge than another oyster reef, Dry Bar, in the western bay area. [ABSTRACT FROM AUTHOR]

At present, little is known about the mechanisms that control water level variations for the Frog Creek system, west-central Florida, which is a mangrove-covered, microtidal, shallow estuary. Although connected with open waters, topographic and roughness constraints can alter expected variability of water levels in this area. Water level variations are especially important for the Frog Creek system, because the increases or decreases in subtidal water level change the present tidal environments. In this paper, 1-year measurements of water levels were examined using the empirical orthogonal function (EOF) method. Water level data from eight stations were first filtered by employing a Lancz6-squared filter because of its ability to eliminate diurnal tidal signals while inducing minimal attenuation in variations with periods of 2 to 3 days, which are usually caused by wind. The filtered water levels were then analyzed using the EOF method to determine relative contributions of various forcing factors. The first three EOF modes explained 64.13%, 33.25%, and 1.55% of total variances and were interpreted by calculating correlation coefficients and coherences. We attributed EOF mode 1 to the variations of coastal subtidal water levels introduced by physical processes with longer periods, such as spring-neap tidal variability and seasonal freshwater river discharge variability. Next, EOF mode 2 was related to the effects of the local N-S wind component, which introduces short-timescale variations of the subtidal water level with typical periods ranging from 2 to 6 days. The effect of river discharge on water level was captured by EOF mode 3. Overall, EOF analysis provides an insightful tool to examine water level disturbances. [ABSTRACT FROM AUTHOR]

Sealey, K.S.; Andiroglu, E.; Lamere, J.; Sobczak, J., and Suraneni, P., 2021. Multifunctional performance of coastal structures based on South Florida coastal environs. Journal of Coastal Research, 37(3), 656–669. Coconut Creek (Florida), ISSN 0749-0208. Coastal communities around the globe are facing the related challenges of sea-level rise, more frequent and extreme storm events, and deteriorating coastal water quality. A multidisciplinary research team with expertise in architecture, ecology, economics, engineering, design, and public art surveyed existing coastal structures to elucidate criteria for a multifunctional performance assessment of these structures in South Florida. Eight coastal survey sites were evaluated to understand their function. Two key variables that affect the coastal structure function are the spatial extent of the structure and the age of the structure. The functional performance was ranked as poor, fair, or good based on (1) ecological functionality (rugosity, minimization of pollution, and coastal plant diversity), (2) engineering functionality (storm, wave, and flood resilience and affordability), and (3) stakeholder functionality (waterfront access, views, and wildlife views). These aspects of functionality were equally weighted to evaluate the impact of each component on the coastal environs. Generally, coastal structure design considers primarily engineering functionality, and these designs consequently have poor ecological functionality. Multifunctionality improved with the horizontal extent of the structure, the occurrence of coastal plants in a buffer zone, and increased public access and use. [ABSTRACT FROM AUTHOR]

This paper introduces the recently developed resource "Characteristics of the Shoreline Change along the Sandy Beaches of the State of Florida: An Atlas" (available on the web). The shoreline positions on which the Atlas is based encompass 2F coastal counties extending over 1162 km of shoreline and averages over almost 140 years. The data were analyzed over three different periods (early, recent, and total) to distinguish mainly beach nourishment and sand bypassing projects, primarily in the recent period. The east and west coastlines of Florida have advanced significantly in the recent period relative to the early period, with the recent and early period average shoreline change rates being +23 cm/y and +18 cm/y on the east coast and +27 cm/y and -7 cm/y on the west coast, respectively. This improvement is attributable to, in part the large quantities of sand placed during nourishment and sand bypass projects. Shoreline changes in the vicinity of the inlets were examined, and it was found that shoreline fluctuations decreased significantly with increasing distance from the inlets, and that sand bypass and nourishment projects reduced the shoreline variability during the recent period. [ABSTRACT FROM AUTHOR]

Santa Rosa Island, situated along the northwestern Florida coast facing the Gulf of Mexico, is an 85-km-long wavedominated low-lying barrier island with well-developed incipient and established dunes. In this paper, we examine the regional-scale effect on coastal dunes by a strong category 3 hurricane, Ivan, through comparison of pre- and poststorm airborne LIDAR (light detecting and ranging) surveys. On the basis of pre-Ivan LIDAR survey data, the elevation of the berm and back beach is typically 2.0 m above MSL (mean sea level). Incipient dunes range from 2.5 to 10 m above MSL, or 0.5 to 8.0 m above the surrounding beach. The hummocky dunes that developed over relic washover platforms are typically less than 4.0 m above MSL. The densely vegetated, established dune fields are composed of dunes less than 7.0 m high and intradune wetlands lying at less than 1.0 m above MSL. The entire island was severely affected by Ivan, which made landfall about 45 km to the west in September 2004. The landscape was substant lly changed by Ivan. Over 70% of the incipient and hummocky dunes were destroyed, and a large portion of the low-lying wetlands was covered by washover. The degree of storm-induced morphology change depends not only on the intensity and duration of the storm but also on the antecedent morphological characteristics of the barrier island. Comparison of pre- and post-Ivan cross-island LIDAR profiles indicates that at most locations, more sand was eroded from the subaerial portion of the barrier island (e.g., beach and dune) than was deposited as washover terraces and lobes. This suggests a net sand loss to the offshore region. Evidence of sand moving alongshore related to the oblique orientation of the dunes was also identified. Under inundation regime, the subaerial sediment deficit could be accounted for by subaqueous sedimentation into the back-barrier bay. [ABSTRACT FROM AUTHOR]

Since 1973, Delray Beach, located on the southeast coast of Florida, USA, has been periodically nourished. The morphological evolution of these nourishments has been influenced by design aspects (e.g, changes in shoreline orientation), extreme events (hurricanes, northeastern storms), and dredging of offshore borrow areas created to provide the nourishment sediments. This paper describes a thorough analysis of the physical processes influencing nourishment performance using the process-based model Delft3D. The analysis distinguishes three steps: (1) a wave analysis, (2) a hydrodynamic analysis, and (3) a morphological analysis. The wave analysis shows that the oldest, deeper, borrow pits (dredged in 1973 and 1978) have the largest effect on the nearshore wave climate, while the effects of the reefs can be considered negligible. Results from the hydrodynamic analysis indicate that differences in wave height cause variations in alongshore current velocities related to differences in wave setup and local wave angle. The morphologic analysis also shows a large influence of the older borrows on fill performance. Bar formation behind the borrows is predicted by the model; however, this feature couldn't be confirmed with 300-m spaced beach profile data. Higher current velocities were predicted in the shadow zone behind borrow areas because of gradients in wave-induced water levels and changes in wave direction induced by the borrows. The higher than average erosion in the southern end of the fill appears to be caused by changes in shoreline orientation and to a lesser degree, borrow area effects. Modeling played a key role in understanding the observed morphological development of the fill. The use of different bathymetric scenarios proved to be a useful method in isolating the physical processes relevant to nourishment performance and assessing their relative effects. [ABSTRACT FROM AUTHOR]

Storm overwash is a critical issue in coastal management efforts to mitigate damage to infrastructure. This paper contributes to those efforts by documenting the findings of a field survey at the Perdido Key, Florida, section of Gulf Islands National Seashore following the landfall of tropical cyclone Isidore in September 2002. The poststorm survey of overwash sites detected scouring along the northern edge of an access road that faced away from the Gulf of Mexico and the oncoming storm surge. Most sites experienced removal of minor amounts of sand and roadbed material, which left the edge of the overlying asphalt road surface unsupported. However, more severe scouring at one site caused the overlying asphalt road surface to fracture and collapse. An extreme example of this process was observed following the landfall of Hurricane Opal at Pensacola Beach, Florida, in 1995. The scouring process and its effects were consistent with a process recognized in fluvial systems as knickpoint development. Related scouring processes known as hydraulic jump and dam overtopping are also discussed. Coastal management options for mitigating this problem include reducing overwash and increasing resistance to scour. Methods to protect dams from overtopping offer potential solutions to this problem. An alternative solution is proposed that would offer protection against minor overwash events; however, it is unlikely that any of the methods discussed herein would be highly effective against an extreme event like Hurricane Opal. [ABSTRACT FROM AUTHOR]

Accuracy of predicting storm surge inundation depends on the model grid resolution. The spatial resolutions of many storm surge models are on the order of hundreds of meters to kilometers, which are not sufficient to resolve irregular shorelines and small topographic features. In this paper, storm surge and inundation simulation for Hurricane Andrew of 1992 was carried out with the unstructured tidal, residual, intertidal mudflat (UnTRIM) hydrodynamic model. A high-resolution unstructured grid with cell sizes as small as 20 m was placed over the Key Biscayne Bay area near Miami to better represent irregular shorelines and small morphological features such as barrier islands, rivers, canals, and inlets. A series of experiments was conducted to test model performance with respect to model grid resolution, time step selection, open boundary condition specification, and tidal influence. Results show that the model simulated maximum surge heights and areas of inundation along the Biscayne Bay coast very well, indicating that the UnTRIM model is useful in simulating storm surge flooding. [ABSTRACT FROM AUTHOR]

Jackson, K.; Wang, P.; Pluckhahn, T.J.; Rogers, J.A., and Thompson, V.D., 2023. Stratigraphic framework, paleoenvironments, and Indigenous terraforming of inshore estuarine subbasins in Tampa Bay, Florida, U.S.A. Journal of Coastal Research, 39(5), 779–815. Charlotte (North Carolina), ISSN 0749-0208. Tampa Bay is a karst-controlled estuary system on Florida's central peninsular Gulf of Mexico coast. Although previous work has reconstructed late-Pleistocene environments (ca. 20–11.5 kya) and early marine influence (ca. 8–5.5 kya) in deeper central portions of the bay, the estuarine development of the shallow inshore subbasins remains poorly understood. Across the late Holocene, Indigenous societies terraformed the coastal strand with large volumes of estuarine mollusk shell, and these anthropogenic landforms constitute coastal barriers that partially enclose marginal tidal bayous. This study integrates sediment coring and archaeological excavations to reconstruct the Holocene estuarine evolution of four inshore subbasins within Tampa Bay. This study synthesizes sedimentological, macrofossil, and archaeological data to describe and differentiate seven sedimentary facies and 18 subfacies representing weathered Miocene limestone at the base, overlain by late-Pleistocene freshwater wetland deposits, followed by Holocene estuarine sediments and late-Holocene shell-terraformed settlements. Four stratigraphic cross-sections and >100 radiocarbon assays are utilized to interpret the sequences of inshore estuary development, situate ancient shell-bearing Native settlements within a geologic and paleoenvironmental framework, and resolve elements of mid- and late-Holocene sea-level history. [ABSTRACT FROM AUTHOR]

Brown, M.T.; Dix, N.; Osborne, T.; Castle, A.; Woodward, W.; Hartnett, A.; Dunnigan, S.; Tanner, S., and McGinley, E., 2023. The impacts of a restoration dredging project and storm events on water quality in a northeast Florida barrier island estuary. Journal of Coastal Research, 39(4), 722–739. Charlotte (North Carolina), ISSN 0749-0208. Previous studies in estuarine systems have demonstrated that both dredging projects and storm events can have profound impacts on water quality, particularly increases in nutrients, sediment loading, and shifts in phytoplankton community biomass. This study provided the opportunity to assess the potential relative impacts of a 9-month-long barrier island restoration dredging operation, in comparison to storm events that shortly followed, on water quality in a well-flushed, subtropical NE Florida estuary. Twice-a-month monitoring of turbidity, total suspended solids, chlorophyll-a, and major nutrients (ammonium, nitrate+nitrite, and orthophosphate) was carried out at six sites near the dredging operation area from November 2016 through October 2018. This timeframe sampled the dredging project from January to September 2017 associated with the reopening of the Summer Haven River on the barrier island side of the Matanzas River estuary. In addition, two major storm events, Hurricane Irma in September 2017 and a 5-day nor'easter in October 2017, took place during the water quality monitoring. Although the dredging project did result in notable impacts on total suspended solids and ammonium concentrations, the results highlight how natural storm events can have more significant and lasting impacts on water quality in a well-flushed estuary, particularly with regard to decreases in salinity, input and remineralization of dissolved organic carbon, and increases in dissolved nutrients. [ABSTRACT FROM AUTHOR]

Vickery, C.G.; Wang, P., and Cheng, J., 2022. Natural and anthropogenic factors controlling circulation at the terminus of a seagrass-covered estuary, Fort DeSoto Bay, West-Central Florida. Journal of Coastal Research, 38(4), 681–698. Coconut Creek (Florida), ISSN 0749-0208. Causeway construction and channel dredging are common engineering activities in shallow estuaries and can significantly alter natural circulation patterns. Bridges are often installed on causeways to improve circulation. This study examines the influence of dredged channels, causeways, and bridges on circulation patterns within a shallow estuary with dense seagrass beds using a calibrated and verified numerical model. For the case of Fort DeSoto Bay in west-central Florida, the causeways disrupted the natural east-west flow and reduced current velocities within the seagrass beds in the southern terminus portion of the estuary by up to 76%. The tidal bridges increased velocity in the stagnant areas by up to 226%. Up to 26% of the tidal prism in the lower half of the bay passes through the bridges during a spring flood-tidal cycle. Thus, the bridges significantly improved tidal flushing between the estuarine cells divided by causeways. The unvegetated dredged channels serve as efficient conduits that facilitate penetration of tidal currents into the southern and terminus of the bay, leading to significantly higher current velocity in the channels and corresponding reduced velocity over the adjacent seagrass beds. The channels allow for improved tidal flushing within the otherwise stagnant southern terminus of the bay and therefore can be designed for the purpose of improving circulation. [ABSTRACT FROM AUTHOR]

Schiariti, J.P. and Salmon, M., 2022. Impact of Sargassum accumulations on loggerhead (Caretta caretta) hatchling recruitment in SE Florida, U.S.A. Journal of Coastal Research, 38(4), 725–734. Coconut Creek (Florida), ISSN 0749-0208. Hatchling loggerhead turtles emerge from subsurface nests on oceanic beaches at night, then crawl toward and enter the sea. Recently, increases in a floating algae (Sargassum spp.) have been reported in the mid-Atlantic and Caribbean, resulting in large accumulation on Florida's beaches. The purpose of this study was to determine if, during the 2020 nesting season, these accumulations acted as a barrier that prevented the hatchlings from crawling to the sea. Seasonal changes in Sargassum density were recorded to determine when, and under what circumstances, hatchlings could cross the accumulated wrack. There was a significant overlap between when Sargassum accumulations peaked and when the turtles emerged, with the result that during the 2020 nesting season the number of hatchlings that entered the ocean was reduced by an estimated 22%. These results suggest that algal accumulations represent a significant threat that could potentially impede the recovery of loggerhead populations that currently are either threatened or endangered, worldwide. [ABSTRACT FROM AUTHOR]

Cheng, J. and Wang, P., 2022. Factors controlling storm-induced morphology changes at an erosional hot spot on a nourished beach, Sand Key barrier island, west-central Florida. Journal of Coastal Research, 38(4), 750–765. Coconut Creek (Florida), ISSN 0749-0208. Beach nourishment has become the dominant sandy shore protection method over the past 40 years. The performance of nourished beaches and therefore the design of renourishment projects are significantly controlled by the presence of erosional hot spots and storm impacts. Based on 5.5-year bimonthly beach profile surveys, along a nourished beach spanning an erosional hot spot, this study examines the hydrodynamic conditions of extratropical (winter) and tropical (summer) storms that cause significant morphology changes. The sand volume loss above the short-term closure depth averaged along the 1.8-km stretch erosional hot spot was 178 m3/m over the 5.5 years after the nourishment. A large portion of this volume loss was caused by several extratropical storms and Hurricane Irma in 2017, when the high, northerly approaching waves were associated with a depressed water level. The northerly approaching waves induced a large longshore sediment transport gradient along the generally north-south trending coast due to wave refraction over a nearby ebb tidal delta. The energetic Hurricane Irma induced a large negative surge and also transported sediment seaward beyond the short-term closure depth. On the other hand, during the passages of typical tropical storms, the southerly approaching waves superimposed on elevated water levels caused substantial beach volume loss above the mean sea level. The eroded sediment deposited on the nearshore sandbar, resulting in conserved sand volume above the short-term closure depth. Understanding the different beach response to extratropical and tropical storms would benefit beach management, especially under the circumstance of increasing storm activities due to climate change. [ABSTRACT FROM AUTHOR]

Fenster, M.S.; Hughes, C.P., and Stutz, M.L., 2022. A survey of global mixed-energy and wave-dominated barrier island distribution and development. Journal of Coastal Research, 38(4), 795–806. Coconut Creek (Florida), ISSN 0749-0208. This study quantifies the length, percentage, and type of development found on global mixed-energy and wave-dominated coastal plain and deltaic barrier islands. Google Earth photographic imagery from 2015–2017 was used to measure the lengths of individual islands, identify infrastructure types 300 m landward of the shoreline, and measure the alongshore extent of each island's land uses. The United States Geological Survey's land-use classification scheme enabled categorization and quantification of predominant structure types. The results from this study showed that, of the 1444 mixed-energy and wave-dominated barrier islands located within 53 countries around the world: (1) 832 (approximately 59%) of those barriers islands have some type of development; (2) approximately 16% of the total length of shorelines (approximately 1,793 km/11,249 km) are developed; (3) wave-dominated barriers (approximately 17%) are more developed than mixed-energy (approximately 14%) barriers; (4) coastal plain (approximately 21%) settings have double the development than deltaic settings; (5) the U.S. contains approximately 66% of all developed global barrier island shorelines and the highest percent development of mixed-energy (New Jersey approximately 67%) and wave-dominated (Florida approximately 62%) coastal plain barrier islands in the world; and (6) high-density, residential dwellings dominate development type and comprise an average 14% of the world's barrier island shorelines. Finally, development percentage and/or land use type do not appear to depend on or correlate with hydrodynamic or geologic setting and coastal processes and geology do not influence development type. Instead, site specific or regional factors most likely dictate the percentage and type of development. [ABSTRACT FROM AUTHOR]

Campbell-Martínez, G.E.; Thetford, M., and Miller, D., 2022. Germination response of three florida panhandle coastal dune plants to salinity. Journal of Coastal Research, 38(3), 585–591. Coconut Creek (Florida), ISSN 0749-0208. Coastal dunes and their ecosystem services are threatened by human pressures warranting active restoration. Understanding dune plant germination responses to salinity is important when considering plant species and direct seeding locations for coastal dune restoration projects. The germination response of three Florida panhandle native coastal dune plant species to various salinity concentrations (0%, 0.25%, 0.50%, 0.75%, and 1% weight per volume) were tested. Species included were coastalplain honeycombhead (Balduina angustifolia (Pursh)B.L.Rob.), coastalsand frostweed (Crocanthemum arenicola (Chapm.)Barnhart), and squareflower (Paronychia erecta (Chapm.)Shinners). Seeds were germinated within germination boxes, placed in growth chambers under species-specific temperatures with a daily 12-hour photoperiod, and monitored weekly for 4 weeks. Germination responses to salinity were species-specific. Coastalplain honeycombhead had intermediate salt tolerance (highest germination at 0%–0.50% salinity), coastalsand frostweed was the least salt tolerant (highest germination at 0%–0.25% salinity), and squareflower was the most salt tolerant species in respect to germination (high germination across all salinities). Germination was delayed for all species at the highest salinity concentrations (0.75%–1%). However, for all three species, at least one-third of all seeds (>39%) at all salinity concentrations germinated by week 4. Results suggest germination for seeds of these species is possible in saline conditions documented within coastal areas before and after hurricane overwash. Future dune restoration studies for these species should test direct seeding of these plants under field conditions. [ABSTRACT FROM AUTHOR]

The failed Deepwater Horizon (DWH) well released approximately 7.0 x 105 m³ of oil into the northern Gulf of Mexico during an 84-day period from 20 April 2010 to 15 July 2010. This study examined the beach oiling that resulted from the DWH spill, specifically the cross-shore distribution of both surface and buried oil, based on a series of field investigations and transport mechanisms following principles of beach morphodynamics. Five types of oil contamination were distinguished, including tar balls, tar patties, tar cakes, oil sheet, and stained sand. All five types were identified both on the beach surface and buried underneath contaminated and clean sand. The cross-shore distribution of surface oil was bound landward by the maximum high-tide wave run-up, which was, in turn, controlled by the incident wave condition. Concentrated surface oil contaminants were often found along the maximum high-tide wave run-up and in the trough landward of the berm crest. The foreshore, with dynamic and constant swash motion, was not conducive for preservation of surface oil deposition. The burial of oil contaminants occurred at similar temporal scales and was driven by the same processes as the initial surface deposition. The buried layers of oil contaminants were documented in varying thicknesses (up to 15 cm) and depths (up to 50 cm) below the surface. The deepest buried oil was found beneath the active (or storm) berm crest and decreased in depth both landward and seaward. Buried oil contaminants can resurface as the beach erodes. Buried oil can be removed through mechanical excavation. Detailed description of cross-shore distribution of oil contaminants relating to beach morphodynamic terminology may help optimizing beach cleanup planning. [ABSTRACT FROM AUTHOR]

Beck, T.M.; Wang, P.; Li, H., and Wu, W., 2020. Sediment bypassing pathways between tidal inlets and adjacent beaches. Journal of Coastal Research, 36(5), 897–914. Coconut Creek (Florida), ISSN 0749-0208. This study investigated the sediment transport pathways in three sandy barrier, tidal inlet systems through sediment tracking within a numerical model that simulates hydrodynamics and morphodynamics. The three tidal inlet systems, Coos Bay, Oregon, Shark River Inlet, New Jersey, and John's Pass, Florida, represented high-, medium-, and low-wave energy regimes for U.S. inlets (Pacific, Atlantic, and Gulf of Mexico Coasts, respectively). Three methods employed to define sediment pathways from the results of a numerical morphology model were evaluated: (1) morphodynamic interpretation, (2) mean transport vectors across the modeled inlet, and (3) sediment tracer migration. The sediment tracing methodology employed in this study allowed for an evaluation of the sediment transport pathways between the various morphologic features of a tidal inlet, as well as their respective processes that drive the exchange of sediments. Characterizing and correlating the dominant and subdominant, or seasonal, sediment pathways between tidal inlet morphologic features (sediment reservoirs) can improve long-term models of an inlet sediment system. Divergences in pathways to subfeature shoals of a complex tidal inlet shoal, such as the updrift and downdrift shoals of an ebb-tidal delta, can be resolved through tracking sediment migration. The results of this study illustrate the value of including sediment-tracking techniques in simulating sediment bypassing and the potential of this application to inform coastal engineering and design modifications to the sediment reservoirs of tidal inlet systems. [ABSTRACT FROM AUTHOR]

Cheng, J. and Wang, P., 2019. Unusual beach changes induced by Hurricane Irma with a negative storm surge and poststorm recovery. Journal of Coastal Research, 35(6), 1185–1199. Coconut Creek (Florida), ISSN 0749-0208. The coast of west-central Florida, facing the Gulf of Mexico, experienced Hurricane Irma with a negative surge of 1.1 m and a highly oblique northerly approaching wave in September 2017. This unusual hydrodynamic condition provides an opportunity to investigate the effect of surge and incident wave direction on morphology changes. Beach profiles, spaced at 300 m apart, along a 15-km stretch of beach were surveyed 2 weeks prior to the passage of Hurricane Irma and 1 week after and continued for up to 5 months after the passage to obtain Irma-induced erosion as well as post-Irma recovery. Owing to the occurrence of negative surge, the profile volume of the dune field remained mostly stable. The majority of beach erosion occurred below mean sea level, with a considerable amount of sediment transported seaward of the depth of closure. This is opposite to the conservation of beach profile volume above depth of closure under several earlier storms with a positive surge. The alongshore variation of overall beach profile volume erosion demonstrates a southward decreasing trend, due to a southward decreasing wave height as controlled by the northerly incident wave. After the passage of Irma, minor beach volume recovery occurred during the calm period of the fall season. Opposite to the typical erosive beach in winter, the most substantial beach accretion and onshore bar movement were observed during the following peak winter season as beach/bar evolved toward equilibrium. The profile volume in the dry beach region experienced a complete recovery in the first 5 months after Hurricane Irma. Shoreline change is a valid proxy for beach volume change during both the erosive and the recovery phase of Irma. The systematically measured beach profiles provide a solid dataset to calibrate process-based models to study beach morphodynamics. [ABSTRACT FROM AUTHOR]

Wozencraft, J.; Dunkin, L.; Reif, M., and Eisemann, E., 2018. A spatial index approach to coastal monitoring: A Florida case study. In: Almar, R.; Almeida, L.P.; Trung Viet, N., and Sall, M. (eds.), Tropical Coastal and Estuarine Dynamics. Journal of Coastal Research, Special Issue No. 81, pp. 67–75. Coconut Creek (Florida), ISSN 0749-0208. Light Detection and Ranging (lidar) topography and bathymetry datasets and high-resolution aerial imagery have much to offer, but are typically very large, and efforts to extract information are often ad-hoc, leaving the full potential of high resolution airborne data unrealized. By developing methods for extracting and presenting consistent parameters and metrics applicable across coastal regions in the United States, this crucial information will become more readily available. Here, it is demonstrated how numerous geomorphological, navigation, and structural parameters are extracted from lidar topographic and bathymetric datasets. In addition, environmental parameters are extracted from hyperspectral imagery. Indices are developed from the extracted parameters to provide an evaluation of coastal engineering projects such as dredging and structures condition, as well as environmental projects including mitigation and restoration. A dashboard developed from the indices offers a clear and comprehensive presentation of coastal resource data products. Coastal condition as it relates to geomorphology, navigation infrastructure, and environmental considerations are presented using 'stop-light' symbology, providing a streamlined and easily interpreted illustration for decision making. The indices provide academia, industry, and government with repeatable, comprehensive coastal assessments that are regionally comparable allowing an integrated approach to management and planning in the coastal zone. [ABSTRACT FROM AUTHOR]

Houston, J.R., 2017. Shoreline change in response to sea-level rise on Florida's west coast. Shoreline position measurements about 300 m apart have been made along the Florida shoreline from the 1800s. There has been net shoreline advance during this time on the Florida E and SW coasts, but the Florida W coast has had net recession. Information is available on factors causing shoreline change on the Florida W coast, including sea-level rise, beach nourishment, loss of sediment to inlets, offshore dredged-sediment disposal, longshore sediment transport, and long-term, onshore sediment transport. Estimates are presented on the contributions these factors have made to shoreline change since the 1800s along 334 km of shoreline in seven west Florida counties. Summing the contributions results in net shoreline recession that agrees with measured recession within standard deviation confidence intervals in each of the counties and for the total shoreline. Sea-level rise is shown to have accounted for less than 20% of the magnitude of all shoreline change (including shoreline advance produced by beach nourishment). Projections of future shoreline change are made using sea-level rise projections of the Intergovernmental Panel for Climate Change (IPCC), along with projections of shoreline change that would be produced by each of the factors. It is shown that beach nourishment quantities at past rates can offset the recessional effects of sea-level rise for most IPCC sea-level rise projections from 2016 to 2065 and 2016 to 2100. A modest increase in nourishment can offset shoreline recession from sea-level rise based on the worst-case IPCC sea-level rise scenario. [ABSTRACT FROM AUTHOR]

Makowski, C.; Finkl, C.W., and Vollmer, H.M., 2016. Classification of continental shelves in terms of geospatially integrated physiographic realms and morphodynamic zones. The continental shelf off southeast Florida contains a range of benthic environments that are discernible via remote sensing platforms because of low turbidity in the water column. Using the Geospatially Integrated Seafloor Classification Scheme (G-ISCS), physiographic realms and associated morphodynamic zones were cognitively interpreted and classified at a nominal scale of 1:6000 across four remote sensing platforms ( i.e. GeoEye IKONOS-2, Landsat-5 Thematic Mapper [TM], Landsat-7 Enhanced Thematic Mapper [ETM], and National Agriculture Imagery Program [NAIP] high-resolution aerial orthoimagery). Attribute tables were created in conjunction with interpretations to quantify and compare spatial relationships between classificatory units and the different remote sensing platforms. Resultant maps exported from ESRI ArcGIS® ArcMap software showed that while IKONOS-2 satellite imagery and NAIP aerial orthoimagery provided the greatest detail, classification of physiographic realms and morphodynamic zones was still possible using TM and ETM satellite images. Overall, it was determined that IKONOS-2 provided the most beneficial imagery when applying such a classification of coastal and seafloor features. It is postulated that accurate delineation of physiographic realms and morphodynamic zones can provide a foundation for more in-depth biogeomorpholocial classification ( e.g., further subdivision into benthic geoforms, coastal landforms, biological cover) along continental shelves. [ABSTRACT FROM AUTHOR]

Houston, J.R., 2015. Shoreline response to sea-level rise on the southwest coast of Florida. The state of Florida has a unique database of shoreline position measured about every 300 m and dating back to the mid-1800s that presents an opportunity to determine the effects of sea-level rise on shoreline position. In addition to sea-level rise (Bruun rule initially assumed), data are available on the southwest coast of Florida for other factors contributing to shoreline change, including beach nourishment, inlet shoal change, and longshore sediment transport. The sum of these factors should have caused significant shoreline recession, but instead the average shoreline position of this coast was stable during the early period from the 1800s to the 1970s (prior to beach nourishment) and strongly accretive from the 1800s to the 2000s. When the Bruun rule is used, shoreline change predicted by the sum of the factors compares poorly with measured data, but it compares quite well when the Dean equilibrium concept is used. The Dean equilibrium concept says that under wave action and with sufficient available offshore sand, shorelines will advance with sea-level rise due to onshore sand transport. Long-term shoreline change data for most of the Florida east coast and the Dutch central coast also support the Dean equilibrium concept. The source of the onshore sand transport in southwest Florida is identified. Sea-level rise results in long-term shoreline advance rather than recession for shorelines with sufficient onshore sand movement from beyond closure depth to the active profile, probably during episodic storms. [ABSTRACT FROM AUTHOR]

Brutsché, K.E.; Wang, P.; Rosati, J.D., and Beck, T.M., 2015. Evolution of a swash zone berm nourishment and influence of berm elevation on the performance of beach-nearshore nourishments along Perdido Key, Florida, USA. A nourishment was placed within the swash zone along eastern Perdido Key, Florida, in 2011-2012 using maintenance-dredged material from nearby Pensacola Pass, referred to here as a 'swash zone berm nourishment.' The study area was divided into three sections, the swash zone berm project and two adjacent areas to the west and east, and was monitored with time series beach surveys. The performance of the 2011-2012 nourishment with a constructed berm elevation of +0.91m North American Vertical Datum 1988 (NAVD88) was compared with two previous nourishments in 1985 and 1989-1991, with +3.0 m NAVD88 and +1.2 m NAVD88 elevations, respectively. The low elevation for the 2011-2012 nourishment allowed natural overwash processes to occur frequently, which resulted in net onshore sediment transport and growth of the active berm. The swash zone berm evolved back to the natural equilibrium profile shape maintained in the study area within 8 months. The high-wave energy conditions associated with the passages of Tropical Storm Debby and Hurricane Isaac accelerated the equilibrium process. Sediment volume gain west of the project area due to longshore spreading of the nourishment occurred mostly in the trough between the shoreline and the bar, rather than on the dry beach. In terms of rate of shoreline retreat, the short 1.2-km 1985 nourishment performed the poorest with a rate of 40 m/y. The long 7.3-km 1989-1991 nourishment performed the best with a retreat rate of 11 m/y. This suggests that high berm elevations do not necessarily lead to better nourishment performance. Instead, longshore extent of a nourishment may dominate project performance. Furthermore, the very high nourishment density of 1550 m3/m did not improve nourishment longevity. [ABSTRACT FROM AUTHOR]

Huang, W.; Hagen, S.C.; Bacopoulos, P., and Teng, F., 2014. Sea-level rise effects on hurricane-induced salinity transport in Apalachicola Bay. Salinity is an important indicator for estuarine ecosystem. Estuarine salinity can be affected by hurricane and sea-level rises. In this study, hydrodynamic modeling study has been conducted to investigate the effects of sea-level rise on hurricane-induced salinity in Apalachicola Bay. By using the dataset for the Hurricane Dennis occurred in July, 2005, model simulations were conducted under different sea-level rise scenarios. Results from model simulations show the effects of sea-level rise on the estuarine salinity transport during different phases of the storm surge. Generally, the increase of water level by either storm surge or sea-level rise results in the intrusion of majority saline sea water from the east to the west through East Pass. Salinity at two oyster bars responds to the storm surge and sea-level rise differently because Cat Point is located in the east and Dry Bar is in the west of the river mouth. In Cat Point, sea-level rise can cause substantial increase of salinity because it is located between the river mouth and East Pass. Salinity at the peak of the storm surge reaches 30 ppt even without sea-level rise. While salinity at the end of the storm surge reduces to about 20 ppt under no sea-level rise condition at Cat Point, it substantially increases to 30 ppt in response to a sea-level rise of 0.2 m. However, in Dry Bar, salinity is less sensitive to the sea-level rise and the storm surge. At the peak of the storm surge, salinity in Dry Bar is 30 ppt, 28 ppt, 30 ppt., under SLR 0.2 m, 0.5 m, and 1.2 m, respectively. However, near the end of the storm surge, salinity is 22 ppt, 22 ppt, and 27 ppt under 0.2 m, 0.5 m, and 1.2 m SLR conditions, respectively. This indicates that, after the storm surge, salinity in Dry Bar can recover to the normal range (below 26 ppt) if sea-level rise is less or equal to 0.5 m. [ABSTRACT FROM AUTHOR]

Nnaji, G.A.; Huang, W.; Gitau, M.W., and Clark II, C., 2014. Frequency analysis of minimum ecological flow and gage height in Suwannee River, Florida. Hydrological frequency analysis has been conducted to estimate minimum ecological flow and gage height for protection of the ecosystem in Suwannee River, Florida, USA. By comparing to observations, results indicate that both Log Pearson Type III and Weibull distributions provide reasonable predictions of low flow frequency curves. However, Log Pearson Type III distribution provides more accurate predictions than Weibull distribution in low flow analysis in Suwannee River. The 7Q10 method, which has been used by United States Geological Service in USA, is defined as the lowest 7-day average flow that occurs on average once every 10 years, which has been used by some water management agencies in USA for river ecological study. Based on 7Q10 method and frequency analysis, the minimum ecological flow and gage height in Suwannee River are proposed for water resources and river ecosystem managements. The study may provide a good reference for minimum ecological flow analysis in other river study sites. [ABSTRACT FROM AUTHOR]

Houston, J.R. and Dean, R.G., 2014. Shoreline change on the east coast of Florida. A shoreline change data base for Florida dating back to the mid-1800s is unique in the United States, and perhaps the world, with thousands of shoreline change measurements at a nominal spacing of 300 m. Moreover, data are available on factors contributing to shoreline change, including beach nourishment, disposal of dredged sand outside the littoral zone, cutting of new inlets and subsequent growth of ebb shoals, and longshore sediment transport into and along the east coast of Florida. Effects of relative sea level rise can be estimated using the Bruun Rule. These factors should have caused significant shoreline recession since the mid-1800s, but instead, the east coast of Florida has experienced significant average shoreline advance. The formation of carbonate sand is shown not to account for this difference. Onshore transport of sand from beyond closure depth, probably during episodic storm events, is the only possible source of the large quantity of sand that has advanced on average the shoreline of Florida's east coast. For shorelines with significant offshore deposits of sand, it is possible that sea level rise in conjunction with wave action contributes to onshore transport and shoreline accretion. [ABSTRACT FROM AUTHOR]

Miller, D.L.; Thetford, M.; Dupree, J., and Atwood, L., 2014. Influence of seasonal changes and shifting substrate on survival of restoration plantings of Schizachyrium maritimum (Gulf bluestem) on Santa Rosa Island, Florida. Environmental gradients on barrier islands are modified by the loss of dunes as a result of hurricane overwash. The success of restoration plantings in posthurricane landscapes is determined by abiotic conditions, including seasonal and spatial gradients of wind speed and substrate transport encountered before dune redevelopment. The response of Schizachyrium maritimum, a dominant, sand-trapping, dune-forming grass of the northern Gulf Coast to month of planting, sand manipulation, and plant spacing was investigated on Santa Rosa Island, Florida. This grass is also a valuable food for endangered beach mice. Seasonal plantings were initiated in 4 months (November 2005, February 2006, June 2006, and August 2006) at each of six sites. For each site and each planting date, plots were split by plant spacing (30 or 45 cm between plants) and again by two sand manipulation regimes (natural sand accumulation or sand level at 3 cm). Sand surface levels were determined and manipulated every 2 weeks. Plant survival and growth were recorded September 2006 and July 2007. Plant survival and growth were greatest for summer plantings, particularly June plantings. Sand burial by natural accumulation did not result in plant death. Most plant death, particularly for November and February plantings, was associated with root exposure and sand loss around transplants. Closer spacing appeared to slow sand loss and plant death for November plantings. Planting of S. maritimum should be restricted to summer months, preferably June, and where sand loss can be minimized by use of mulch or other sand stabilizing methods. [ABSTRACT FROM AUTHOR]

Multiple hurricanes impacted southeast Florida during 2004 and 2005, producing record rainfall and large-scale stormwater runoff into the urbanized St. Lucie Estuary (SLE). To assess effects on water quality, field samples were taken in June and November 2005 and March 2006 along the SLE's three main segments: the South Fork, connected via the C-44 canal to Lake Okeechobee; the North Fork, which receives residential and agricultural runoff from the C-23 and C-24 canals; and the Middle Estuary, which flows into the Indian River Lagoon and Atlantic Ocean. Salinities were <1%o throughout the normally brackish estuary during the 2005 samplings, but returned to near-normal levels by March 2006 in all but the South Fork. Low salinities in 2005 correlated with low dissolved oxygen, high turbidity, elevated nitrogen and phosphorus concentrations, and high fecal and total coliform counts. Highest turbidity (84.4 NTU), nitrate (37.9 μM), and total dissolved nitrogen (130.8 μM) concentrations occurred in the South Fork, whereas the highest ammonium (15.4 μM), soluble reactive phosphorus (10.5 μM), and total dissolved phosphorus (13.8 μM) concentrations occurred in the North Fork. High fecal and total coliform counts occurred in tidal creeks adjacent to dense residential areas that rely on septic tanks for on-site sewage disposal. The data suggest that increased stormwater retention, minimization of freshwater releases from Lake Okeechobee, and enhanced treatment of both stormwater and sewage are needed to mitigate future stormwater-driven water quality perturbations in the SLE. [ABSTRACT FROM AUTHOR]

We studied the hydrodynamic response caused by the four major hurricanes that struck Florida's coasts in 2004; Charley, Frances, Ivan, and Jeanne. A large-scale, shallow-water-equation model was applied so as to simulate wind and tidally driven hydrodynamics from the deep ocean into the shelf and coastal waters of Florida. Hurricane Ivan served as the calibration case, where the adjusted parameter was the wind drag coefficient. We identified an "increased" wind drag coefficient to perform best and suggest it as a first approximation to the wave contribution to the hydrodynamics. The increased drag coefficient is offered to the consulting and/or forecasting communities, who are frequently without wave-modeling resources, as a pragmatic approach to approximate for waves. Hurricanes Charley, Frances, and Jeanne serve as the validation cases in which the increased wind drag coefficient was applied. Analysis was performed by inspection of maximum water-surface elevations, which are interpreted in terms of shelf and bay dynamics for the west coast hurricane cases (Charley and Ivan) and in terms of channel hydraulics for the east coast hurricane cases (Frances and Jeanne). We conclude that the broad shelf off Florida's west coast allows the storm tide to accumulate along the open coast and that the embayments further magnify the storm tide, and that the Atlantic Intracoastal Waterway along Florida's east coast is effective in propagating storm tide, where we show compartmentalization of the storm tide in the Indian River lagoon as caused by the flow impediment of the causeway abutments. [ABSTRACT FROM AUTHOR]

Observations of optical and hydrodynamic processes were made on the open beach on Santa Rosa Island, Florida, in March 1995. This study focuses on the passage of two cold fronts. The observations have been supplemented by a bio-optical model; a suite of hydrodynamic models to simulate coastal flows forced by waves, tides, local wind, and coastal sea level; and a geo-optical model that predicts scattering by mineral particles resuspended by wave action. These models have been used to examine the interaction of atmospheric forcing and hydrodynamics with respect to the observed marine hydrosol. The optical and hydrodynamic measurements, and the model results, have been used to conceive a cold-front regime model of the hydrosol for open beaches in the Gulf of Mexico. The optical environment during the cold front was determined by three hydrosol phases: (1) a prefrontal steady-state hydrosol consisting of fine resuspended mineral particles, phytoplankton cells, organic detritus, and colored dissolved organic matter; (2) a frontal phase dominated by resuspended mineral particles; and (3) a postfrontal hydrosol containing large phytoplankton, detritus, and fine mineral particles. This concept is useful for identifying the physical processes responsible for observed optical properties. It should be applicable to other regions and types of events. [ABSTRACT FROM AUTHOR]

The Casuarina spp. are invasive plants in Florida that threaten biological diversity and beach integrity of coastal habitats. The trees include three species and their hybrids that aggressively invade riverine and coastal areas. Of the three species, C. equisetifolia and C. glauca are highly salt tolerant and widespread in coastal areas. The third species, C. cunninghamiana, invades riverine habitats. These species pose dangers to both the environment and public safety. The environmental damage includes interfering with nesting by endangered sea turtles, American crocodiles, and the rare swallow-tailed kite. Additionally, allelochemical leachates reduce germination and establishment of native vegetation. Casuarina-infested beaches are more prone to sand loss and erosion. Moreover, with shallow roots and tall canopies, they are among the first trees to fall in high winds and as such restrict evacuation efforts during hurricanes. Control of these species is mostly with herbicides, requiring repeated applications and monitoring. One of the most cost-effective means of controlling these invasive species would be with classical biological control. Australian surveys for potential biological control agents began in 2004, resulting in the discovery of several promising candidates. These include seed-feeding torymid wasps, defoliating caterpillars and weevils, leaf tip gall-formers from cecidomyiid midges, and sap-feeding psyllids. Continued work is needed to determine the suitability of these species for biological control. Despite conflicts of interest expressed by some homeowners and the agricultural industry who value the trees for shade and windbreaks, there are good prospects for safe and effective biological control of these invasive species. [ABSTRACT FROM AUTHOR]

A 6-year survey (1993-1998) is summarized for fish collected from chemically contaminated, urbanized bayous in northwest Florida. Fifty-two monthly collections (January-November) using trawls and seines occurred at 22 sites located in three adjacent bayous associated with the Pensacola Bay Estuary. Hurricanes Erin (Category 2) and Opal (Category 3) made landfall near the study area, and a state-wide entanglement net ban was initiated during the survey period. Approximately 585,000 fish were collected, which represented 80 species and 66 genera. The assemblages were dominated by estuarine-dependent and resident species similar to those commonly found in several nearby estuaries. Of these, Leiostomus xanthurus, Brevoortia patronus, Anchoa mitchilli, Lagodon rhomboides, and Menidia peninsulae composed 95% or more of the total catch. The total number of species for each collection ranged from 8 to 23, total abundances varied from 140 to 14,315 individuals, and Shannon diversity index values (H9) were between 0.02 and 0.97. Mean species numbers and diversity index values were more consistent monthly than fish total abundance, which was influenced by seasonal occurrences of estuarine-dependent species. Hurricane effects were specific to the hurricane, structural parameter, species, and bayou. The posthurricane reductions in salinity (17% to 69%) and the few changes in fish abundance were usually temporary and within monthly and interannual variability. The resiliency of the fish assemblages to natural and anthropogenic stresses represents a survival advantage and readiness for future climatic change. [ABSTRACT FROM AUTHOR]

The coastal zone of the United States is a major source of economic growth and as a result has seen significant increases in population over the past 50 years. Most aspects of the coastal economy-tourism and residential and commercial development-are heavily dependent upon the environmental preservation and recreational quality of ocean beaches. In earlier work, we documented the economic benefits of ocean beach enhancement projects on several important Florida tourism-dependent counties, which are reflected in greater-than-expected increased earnings in the tourism sector. However, the direction of causality of the analysis was somewhat ambiguous. Although we anticipated that beach nourishment projects would attract visitors, it is equally true that, in the allocation of scarce beach nourishment project dollars, it is likely that eroding beaches in areas that are already flourishing tourist destinations will attract beach nourishment funding to preserve their tourist industries. This article links an exploratory spatial data analysis of the tourism sector with a statistical study of the economic determinants of coastal tourism in Florida. Using the predicted likelihood of beach nourishment projects over the 1970-2000 study period as an explanatory variable, we estimate the growth in earnings in the tourism sector between 1970 and 2000. This gives us a clearer understanding of the complex temporal and spatial relationships that influence the coastal economy. [ABSTRACT FROM AUTHOR]

Pleistocene carbonates of south Florida and islands of the Florida Keys are currently divided into five marine sequences designated, from oldest to youngest, the Q1-Q5 units. The units include a mosaic of freshwater and shallow marine deposits that accumulated on the Florida platform during high sea-level stands. The units are separated by regionalscale subaerial-exposure surfaces that formed during glacioeustatic lowstands. Analyses of cores recovered at Grossman Ridge Rock Reef and Joe Ree Rock Reef in the Florida Everglades reveal additional subaerial-exposure surfaces that are used to delineate subdivisions within units Q1 (Q1a-Q1b), Q2 (Q2a-Q2d), and Q4 (Q4a-Q4b). Units Q1-Q5 preserve evidence of at least 10 separate sea-level highstands, rather than 5 as indicated by previous studies. Compilation of available uranium-series dates on corals recovered from the Florida Keys indicates that the Q4 unit accreted during sea-level maxima associated with marine oxygen-isotope Stage 9 (Q4a) and isotope Stage 7 (Q4b). The Q5 unit formed during isotope Stage 5. No reliable dates are available for units Q1-Q3. We infer that unit Q3 was formed during the extended sea-level highstand of isotope Stage 11 and that units Q2 and Q1 predate isotope Stage 11. [ABSTRACT FROM AUTHOR]

Producing thematic coral reef benthic habitat maps from single-beam acoustic backscatter has been hindered by uncertainties in interpreting the acoustic energy parameters E1 (tail of 1st echo) and E2 (complete 2nd echo), typically limiting such maps to sediment classification schemes. In this study, acoustic interpretation was guided by high-resolution lidar (LIght Detection And Ranging) bathymetry. Each acoustic record, acquired from a BioSonics DT-X echosounder and multiplexed 38 and 418 kHz transducers, was paired with a spatially-coincident value of a lidar-derived proxy for topographic complexity, reef-volume (RV), and its membership to one of eight benthic habitat classes, delineated from lidar imagery, ground-truthing, and characterization of epibenthic biota. The discriminatory capabilities of the 38 and 418 kHz signals were generally similar. Individually, the E1 and E2 of both frequencies differentiated between levels of RV and most habitat classes, but could not unambiguously delineate habitats. Plotted in E1:E2 Cartesian space, both frequencies formed two main groupings: uncolonized sand habitats and colonized reefal habitats. E1 and E2 were significantly correlated at both frequencies: positively over sand habitats and negatively over reefal habitats, where the scattering influence of epibenthic biota strengthened the E1:E2 interdependence. However, sufficient independence existed between E1 and E2 to clearly delineate habitats using the multi-echo E1:E2 bottom ratio method. The point-by-point calibration provided by the lidar data was essential for resolving the uncertainties surrounding the factors informing the acoustic parameters in a large, survey-scale dataset. The findings of this study indicate that properly interpreted single-beam acoustic data can be used to thematically categorize coral reef benthic habitats. [ABSTRACT FROM AUTHOR]

Coral reefs represent one of the most irregular substrates in the marine environment. This roughness or topographic complexity is an important structural characteristic of reef habitats that affects a number of ecological and environmental attributes, including species diversity and water circulation. Little is known about the range of topographic complexity exhibited within a reef or between different reef systems. The objective of this study was to quantify topographic complexity for a 5-km x 5-km reefscape along the northern Florida Keys reef tract, over spatial scales ranging from meters to hundreds of meters. The underlying dataset was a 1-m spatial resolution, digital elevation model constructed from lidar measurements. Topographic complexity was quantified using a fractal algorithm, which provided a multi-scale characterization of reef roughness. The computed fractal dimensions (D) are a measure of substrate irregularity and are bounded between values of 2 and 3. Spatial patterns in D were positively correlated with known reef zonation in the area. Landward regions of the study site contain relatively smooth (D ≈ 2.35) flat-topped patch reefs, which give way to rougher (D ≈ 2.5), deep, knoll-shaped patch reefs. The seaward boundary contains a mixture of substrate features, including discontinuous shelf-edge reefs, and exhibits a corresponding range of roughness values (2.28 ≤ D ≤ 2.61). [ABSTRACT FROM AUTHOR]

Time-frequency techniques to characterize cuspate patterns in light detection and ranging (lidar) data are introduced using examples from the Atlantic coast of Florida, United States. These techniques permit the efficient study of beach face landforms over many kilometers of coastline at multiple spatial scales. From a lidar image, a beach-parallel spatial series is generated. Here, this series is the shore-normal position of a specific elevation (contour line). Well-established time-frequency analysis techniques, wavelet transforms, and S-Transforms, are then applied to the spatial series. These methods yield results entirely compatible with the traditional method of estimating the spacing of cuspate features. In addition, confidence intervals are readily established for the spatial extent and wavelengths of cuspate landforms simultaneously at multiple scales. Examples show this method is useful for capturing transitions in cuspate shapes. With the advent of land-based time-lapse lidar, such techniques should be particularly useful for characterizing the evolution of cuspate landforms and testing models for beach face dynamics. [ABSTRACT FROM AUTHOR]

Quantification of the sediment transport processes in the Fort Pierce Inlet, Florida area and the influence of the inlet onto the adjacent beaches was performed by means of analytical methods. This analysis is formalized as a sediment budget and is based on available survey data, nourishment events, and dredging records of the navigational channel at Fort Pierce Inlet, which cover the period from 1972 to 2002. Available survey data encompass shoreline distances approximately 9.7 km north and 24.7 km south of Fort Pierce Inlet. Three intersurvey periods were examined in this study: 1972 to 1987, 1987 to 1997, and 1997 to 2002. Average annual sediment volume and shoreline changes derived from the profile data collected during these three periods were analyzed. Application of general sediment budget principles established that for the total period from 1972 to 2002, there was an average annual deficit of approximately 12,500 m3/y on the beach south (downdrift) of Fort Pierce Inlet. The general sediment budget suggests that 88,700 m3/y enter the north boundary of Riomar Beach some 18 km north of the inlet; 62,700 m3/y enter the north boundary of St. Lucie County some 10 km north of the inlet; and 43,600 m3/y leave the south boundary of St. Lucie County some 25 km south of the inlet. Application of numerical modeling to develop an understanding and predictability of the performance of beach nourishment south of the inlet was carried out as a supporting method to better understand the littoral processes in the area. Recommendations to improve the sediment management practices, including sand bypassing to restore balance to the south beaches, are presented. [ABSTRACT FROM AUTHOR]

Predictions of extreme coastal water levels are important to coastal engineering design and hazard mitigations in Florida. Annual maximum water levels are often used in frequency analysis of 1% annual chance flood in coastal flood hazard mapping. However, because of the damage to measurement instruments during hurricanes, some annual maximum water levels may be missed, which makes coastal flood hazard analysis difficult. In this study, a technique was developed to use artificial neural network and harmonic analysis for recovering extreme coastal water levels during hurricanes. The total water levels are decomposed into tidal components and storm surge. Tidal components can be derived by harmonic analysis, whereas storm surge can be predicted by neural network modeling on the basis of the observations of local wind speeds and atmospheric pressure. The neural network model uses three-layer feed-forward back-propagation structure with advanced scaled conjugate training algorithm. The method presented in this study has been successfully tested in Panama City Beach, located on the Florida coast, for Hurricane Dennis (2005), Hurricane Ivan (2004), and Hurricane Opal (1975). Model-predicted peak elevations reasonably match with observations for the three hurricane events. The decomposed storm surge hydrograph also make it possible for the analysis of potential extreme water levels if the storm surge occurs during spring high tide. [ABSTRACT FROM AUTHOR]

The Loxahatchee River, a 500 km2 watershed on the southeast Florida coast, is a barrier-impounded drowned river valley experiencing rapid urbanization during the past 50 years. The estuary is currently composed of a sandy central basin with bifurcating forks accumulating organic-rich muddy sands. The Northwest Fork drains natural forest, residential, and agricultural catchments and has a much larger bayhead delta than the channelized Southwest Fork, which is only 50 years old and diverts much of the flow from the Northwest Fork. Sediment accumulation rates within muddy sand deposits are about 2-3 mm a-1, commensurate within error of the current rate of local sea-level rise. Previously established Holocene accumulation rates are close to relative sea-level rise, implying that sediment accumulation is in equilibrium with the creation of accommodation space. The main anthropogenic influences have been changes in surface sediment texture corresponding to dredging-induced modification of tidal currents and a localized>threefold increase in sediment accumulation rate supplied by sources local to the estuary. Late Holocene sedimentation has been episodic, and lithofacies vary from bioturbated transgressive sands at depth to peat and laminated fine-grained sediments then back to mottled muddy sands in the uppermost strata. This facies transition is attributed to a change of water column stratification conditions caused by decreased tidal flushing in the estuary possibly brought about by variation in sea level or episodic inlet closure by littoral sand transport. The magnitude of the anthropogenic changes in sedimentation is roughly equal with natural changes in lithofacies formation. [ABSTRACT FROM AUTHOR]

Continental shelf environments along the Florida Atlantic southeast coast offshore Palm Beach County were mapped by interpreting seafloor topography derived from airborne laser bathymetry. The study area covered approximately 270 km² along 75 km of coast, extending from the shore to about 55 m water depth beyond the shelf break to the upper Florida-Hatteras Slope. Forty-two mapping units were used to depict seafloor features that ranged from bedrock outcrops and coral reefs to different types of morphosedimentary bodies. Background theory and protocols of geomorphological symbolization are provided as a rationale for the seafloor mapping. Geomorphological mapping symbols were developed specifically for this project and collected in a symbol library as part of an ArcInfo GIS extension that was used to produce the maps in a GIS environment. Spatial distribution patterns of landform assemblages evident in the color-pattern mapping units permitted regionalization of shelf environments into three primary geomorphological reaches: Reach I, Sand Flats and Karst Topography; Reach II, Sand Flats and Coral Reefs; and Reach III, Sand Flats, Hardgrounds, and Coral Reefs. The main hardbottom mapping units include rock outcrop and subcrop, rock rubble, ridge fields, and structural sand flats. Sandy nontidal morphosedimentary bodies include diabathic channel fields, dune fields, sand flats, and bar and trough systems. Tidal morphosedimentary features include ebb-tidal deltas, sandbars, and lobe bars. Results of this mapping effort showed that it is possible to map marine and drowned terrestrial landforms on the continental shelf as depicted in high-resolution airborne laser bathymetry. Adaptation of existing symbols or development of specialized symbolization was required to show geomorphic units to advantage. These maps, which characterize shelf environments, are contextualized in terms of shapes, forms, materials, and coastal process zones. These types of maps find immediate application in regional and detailed sand searches for beach renourishment, subsea cable and pipeline routes, wave and current modeling studies, and environmental management. [ABSTRACT FROM AUTHOR]

To create maps of nearshore benthic habitats of Broward County, Florida, from 0 to 35 m depth, we combined laser bathymetry, acoustic ground discrimination, subbottom profiling, and aerial photography data in a geographic information system (GIS). A mosaic of interpolated, sun-shaded, laser bathymetry data served as the foundation upon which acoustic ground discrimination, limited subbottom profiling and aerial photography, and groundtruthing data aided in interpretation of habitats. Mapping criteria similar to NOAA biogeographic Caribbean mapping were used to allow for a comparable output. Expert-driven visual interpretation outlined geomorphological features at a scale of 1 : 6000 with a minimum mapping unit of 1 acre. Acoustic data were then used to differentiate areas of similar geomorphology by their acoustic diversity into areas of high and low scatter, which could be equated to rugosity created by either the substratum or benthic fauna. Of the approximately 112 km² mapped, 56.62 km² were coral reef and colonized hard bottom (50.42%), 54.78 km² were unconsolidated sediments (46.80%), and 0.43 km² were other categories (2.78%). Three linear reef complexes exist. The outermost linear reef has a mature windward reef morphology including a drowned spur and groove system, which was absent on the other two reef lines. The acoustic ground discrimination and groundtruthing showed different benthic habitats on the outer vs. middle and inner reefs. Higher acoustic scatter could be related to taller benthos and more rugose substratum. A considerable amount of colonized pavement (nearshore hard grounds) was found inshore. The map of Broward County yielded a high overall accuracy of 89.6%, only slightly less than the photo-interpreted NOAA Caribbean maps (overall accuracy of 91.1%). User and producer accuracies within each category were also similar. The combined technique approach was effective and accurate, and similar methodology can be used in other areas where photo interpretation is not feasible because of turbidity or depth limitations. [ABSTRACT FROM AUTHOR]

Subtropical coastal sand dune ecosystems have been greatly altered by agricultural use, invasive exotic encroachment, urban development, and beach raking, rendering several plant species endangered or threatened. Restoration planning of this ecosystem will benefit from a comprehensive study on how environmental variables change across the coast- to-inland gradient of this ecosystem and it is therefore presented here. We also examined the relationship between the environmental characteristics and plant species composition across the gradient. We used the two largest extents of remaining dune ecosystem on the southeastern coast of Florida, where relatively intact populations of endangered species occur. Vegetation and environmental data were collected from 97 3 ×8 m plots in two sand dune parks along the coast-inland gradient. Soil moisture, most nutrients, cation exchange capacity, and organic matter accumulation increased with distance from the coast, whereas pH and salt spray decreased. The number of species per plot was higher at further distances from the coast at one site only, and higher woody cover was associated with less species diversity at the other site. Canonical correspondence analysis revealed the importance of P, Mg, Ca, pH, cation exchange capacity, organic matter, estimated nitrogen release, and salt spray in affecting vegetation zonation. We conclude that soil chemistry is the most determinant factor of community zonation in these subtropical dunes. Restoration planning should be site specific because of the differences in environmental factors between the two study sites. [ABSTRACT FROM AUTHOR]

Direct observations of the storm surge and the subsequent long-wave response induced by Hurricane Wilma's landfall on the West Coast of Florida on 24 October 2005 are presented. The data set consists of weeklong time series of storm surge and barometric pressure measured by the U.S. Geological Survey (USGS) Florida Integrated Science Center. The survey area spanned more than 100 km alongshore from the landfall site northward. The USGS data were augmented with measurements at the National Oceanic and Atmospheric Administration tide gauge and Coastal Marine Automated Network (CMAN) stations. At the time of Wilma's arrival, the storm surge was minimal to the north of landfall site but was significant in the southern sector. Subsequently, it evolved into an edge wave pulse propagating northward as Wilma moved inland and the surge was no longer sustained by the wind forcing. The height of the wave pulse exceeded 1.5 m in detided sea level data. However, its magnitude was somewhat obscured in direct surge measurements because the wave pulse propagated during the low tide. The duration of this wave pulse was approximately 6 hours. The propagation speed of the wave front was ∼25 m s-1, while the pulse crest traveled at a lower speed of ∼10 m s-1, which indicates the dispersion effects. A relatively low phase speed suggests that the wave energy was trapped nearshore, in the water depth of 10-20 m. The wave pulse was followed by a train of weaker wavelike undulations, also propagating northward. The edge wave pulse seemed to be attenuated by a complex topography in the vicinity of Sanibel Island-Pine Island. [ABSTRACT FROM AUTHOR]

During Hurricane Ivan (2004), dunes in undeveloped sections of northwest Florida were significantly reduced in height through direct wave erosion and the transfer of sediment to the backbarrier by overwash. The poststorm morphology of the island consists of a narrow beach face, multiple breach corridors, a washover terrace, and a remnant secondary dune that was further eroded in 2005 by Tropical Storm Arlene and Hurricanes Dennis and Katrina. The redevelopment of this dune will direct the response of the island to future storms, but the mechanisms of posthurricane dune recovery are unclear, particularly in this low-energy coastal environment. The recovery is further complicated by a swale that was created through a knickpoint effect on an adjacent road. The swale was reinforced when the road surface was removed and as a berm developed during the recovery of the beach face. Field observations suggest that sediment transport across the narrow beach face and berm is limited by a lag of shells and gravel from the pre-Ivan roadbed. As a consequence, sediment input to the dune is relatively minor with onshore winds, despite the presence of fans deposited during frontal storms in the swale behind the berm. The resulting sediment transport gradient across the seaward slope of the dune is more reflective of the expanding fetch than topographic acceleration and the drag imposed by the sparse vegetation. In contrast, there is a larger sediment input to the dune during offshore winds in response to the larger fetch across the washover terrace, despite the presence of a lag. It is concluded that posthurricane dune recovery in this area is strongly dependent on the deposition of sediment during frontal storms and the resulting development of a sand ramp through the swale. This will increase both the availability of sediment and the fetch for winds directly or obliquely onshore. [ABSTRACT FROM AUTHOR]

A sand deficit on Florida's Atlantic coast affects sea turtle nesting, dune ecosystems, and storm protection. Ecological benefits of restoring very large deficits could exceed ecological costs. Dredging and beach nourishment databases revealed sand disposal dynamics and deficit size. Dredge-and-fill activities increased after 1950, peaked in the 1980s, then declined somewhat. Most sand disposal accompanied channel and harbor deepening; little was primarily for beach nourishment. Until the 1970s most dredged material was placed outside the coastal sand-sharing system (offshore and upland). After 1970, beach and nearshore disposal rapidly increased, but generally involved sand already within the system. Moreover, offshore and upland disposal did not immediately decline. To date, little sand has been returned. By 2003, net removal totaled ∼130 × 106 m3. Channels and harbors increased by ∼70 × 106 m3, leaving 60 × 106 m3 of standing sand deficit. Jetties could have redistributed another 70 × 106 m3 from beaches and dunes to inlet shoals. Overall, loss of beaches and dunes could approach 130 × 106 m3. Engineering responses to past objections have improved both habitat suitability and longevity of nourished beaches. Through field trials and adaptive management principles, ecologists could now develop beach nourishment into a management tool to rebuild lost habitat, restore the sand deficit, and stockpile additional sand before nonessential channels and harbors are allowed to refill. With large projects, sand from offshore, upland, and ebb shoal sites and natural wave energy for stable beach building, beach and dune habitat can be restored within decades, better preparing threatened animals for rising sea level. [ABSTRACT FROM AUTHOR]