3,001 research outputs found

    The State of Coral Reef Ecosystems of Southeast Florida

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    The northern extension of the Florida reef tract and a complex of limestone ridges run parallel to the subtropical Atlantic coastline of southeast Florida. Spanning 170 km from the northern border of Biscayne National Park (BNP) in Miami-Dade County to the St. Lucie Inlet in Martin County, the reefs and hardbottom areas in this region support a rich and diverse biological community (Figure 5.1). Nearshore reef habitats in southeast Florida include hardbottom areas, patch reefs and worm reefs (Phragmatopoma spp.) exhibiting abundant octocoral, macroalgae, stony coral and sponge assemblages. Offshore, coral reef associated biotic assemblages occur on linear Holocene Acropora palmata mid-shelf and shelf margin reefs that extend from Miami Dade County to Palm Beach County (Lighty, 1977; Figure 5.2). Anastasia Formation limestone ridges and terraces colonized by reef biota characterize the reefs from Palm Beach County to Martin County (Cooke and Mossom, 1929). The coastal region of southeast Florida is highly developed, containing one third of Florida’s population of 16 million people (U.S. Census Bureau, 2006). Many southeast Florida reefs are located just 1.5 km from this urbanized shoreline. Despite their unique position as the highest latitude reefs along the western Atlantic seaboard, the reefs of southeast Florida have only recently received limited scientific and resource management attention. Andrews et al. (2005) discussed the reefs of southeast Florida and the critical need to implement actions that fill resource knowledge gaps and address conservation and threats to reef health. This report further examines and updates the list of stressors imperiling the health of southeast Florida’s reefs, and presents information gained from new research, monitoring and management efforts to determine the extent and condition of reef resources in this distinctive region

    Remote sensing of environmental disturbance

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    Color, color infrared, and minus-blue films obtained by RB-57 remote sensing aircraft at an altitude of 60,000 feet over Boca Raton and Southeast Florida Earth Resources Test Site were analyzed for nine different types of photographic images of the geographic patterns of the surface. Results of these analyses are briefly described

    Age and Growth of Hogfish (Lachnolaimus maximus) in Southeast Florida

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    Hogfish (Lachnolaimus maximus; Walbaum 1792) from Southeast Florida were aged using sectioned otoliths and growth rates were calculated using the von Bertalanffy growth equation. The samples were collected from Broward County (n=209); other regions of Southeast Florida (n=18), the Florida Keys (n=35) and Bahamas (n=43). Growth rates were determined for each of these areas and were then compared to previously reported growth rates from other regions including the eastern Gulf of Mexico and Florida Keys. There was significant separation at the 95% confidence level between growth rates from each reagion. The average maximum fork length increased, from the Florida Keys (336mm) to Southeast Florida (414-mm) by 78-mm. However, the annual survival rate was the same (S=61%) between these two regions and the maximum age of Southeast Florida (age 12) was still half that of the previously reported eastern Gulf (age 23). Broward County was divided into three reef zones each at different depths (5-m, 10-m, and 20-m) and growth rate and survival rate were compared between zones. Results showed a decrease in maximum fork length with reef depth (857-mm, 420-mm, 352-mm), as well as an increase in mean age (age 3, 4, 5), maximum age (9, 10, 12), and survival (42%, 65%, 73%), respectively. The decrease in observed growth rate of an area as a whole (e.g. Florida Keys) may represent an example of Lee’s phenomena caused by increased top-down selective fishing pressure. However, the growth rates of individual hogfish are most likely a result of differences in habitat and food resource availability. This study provides baseline age and growth information for hogfish in Southeast Florida prior to the recent changes to the fishery regulations, which will help fisheries management better understand the effects of alternative management strategies

    Ecosystem Indicators for Southeast Florida Beaches

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    Beaches are landscapes valued greatly by society that, when left intact, support both ecological processes and sustainable use. In Southeast Florida, alteration of beaches for human activities has resulted in substantial loss of naturally functioning beach habitat and reduced biological diversity. Of particular importance is the impact on beach ecosystems by the nearby urban environment. Beaches are dynamic ecosystems that require space to respond to natural or anthropogenic drivers and pressures. In Southeast Florida urban development has restricted or eliminated the ability of most beaches to react in a manner that conserves the natural beach ecosystem. The frequent result has been oceanfront areas with little or no intact habitat and limited opportunities for restoration, though disturbed beaches may still provide opportunities for ocean access, recreation, and other socioeconomic benefits in highly urbanized areas. In this study we present a framework for selecting relevant ecosystem and human dimension indicators for the beaches of Southeast Florida based on a conceptual ecosystem model. To capture the level of beach disturbance relatively pristine beaches and heavily altered beaches are endpoints in a continuum of beach development. Across this continuum nine indicators were developed to quantify beach condition. For ecosystem and human dimension assessment purposes, beaches were placed in one of two overarching categories: undeveloped to relatively undeveloped, or developed to highly developed. Nine selected indicators are then assessed as good (3), fair (2), or poor (1). The indicator scores are then summed to produce a total condition score for a particular beach. This simple ‘stop-light’ method is applicable even when there are limited data and provides a useful relative determination of ecosystem condition. Case studies employing this methodology are presented for three Southeast Florida beaches ranging from mostly natural to highly developed condition. The indicators directly address both ecosystem and human dimension goals to maintain healthy, sustainable, and useable beaches and shorelines in Southeast Florida. They balance the ecological benefit of remaining natural beaches with the societal benefit of recreational opportunities and access for a beach that can no longer sustain a suitable ecosystem. Each indicator is interpreted in the context of the trade-offs among multiple ecosystem and human dimension services provided by most beaches in Southeast Florida

    A new species of Neonella (Araneae: Salticidae) from southeast Florida

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    A new species of Neonella is described that has a distribution apparently restricted to the southeast coast of Florida. So far, it has only been found in Brevard and Monroe counties. It is closely related to N. mayaguez Galiano from Puerto Rico

    Variation in Coral Recruitment and Juvenile Distribution Along the Southeast Florida Reef Tract

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    Coral recruitment in Southeast Florida is being outpaced by mortality, resulting in population declines in many species. Identifying the coral species most likely to recruit and survive on Southeast Florida reefs and evaluating spatial variation in recruitment and survivorship is crucial for managing decreasing coral populations. This study focuses on 12 sites in Broward and Miami-Dade counties that have served as long-term stations for monitoring adult coral cover and demographics. At each site, thirty-two 225cm2 grooved terracotta settlement tiles were attached to the substrate in winter of 2015 and retrieved in winter of 2016 to evaluate scleractinian and octocoral recruitment rates. Thirty-two corresponding 0.25 m2 quadrats were surveyed in situ for coralsconditions, such as Poritidae, Siderastreidae, and Octocorallia, exhibit signs of recruitment success and/or juvenile survivorship. Scleractinian recruitment was not variable spatially, but juvenile densities varied on site-level spatial scales, suggesting that differential survivorship structures adult scleractinian communities. This study will inform reef management and restoration efforts within Southeast Florida by identifying sites and species with potential to recover from disturbance through natural recruitment processes

    Recovery of Injured Giant Barrel Sponges, Xestospongia muta, Offshore Southeast Florida

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    Giant barrel sponges, Xestospongia muta, are abundant and important components of the southeast Florida reef system, and are frequently injured from anthropogenic and natural disturbances. There is limited information on the capacity of X. muta to recover from injury and on methods to reattach X. muta fragments. In late 2002, hundreds of barrel sponges offshore southeast Florida (Broward County) were accidentally injured during an authorized dredging operation. In early 2003, two to three months post-injury, 93% of 656 assessed injured sponges appeared to be recovering. In 2006, three years post-injury, nearly 90% of 114 monitored sponges continued to show signs of recovery. Growth rates were estimated by measuring sponge height above visual injury scars and ranged from 0.7 cm yr- ¹ to 6.0 cm yr- ¹. Information on the artificially reattached fragments is limited but did show that X. muta fragments can reattach. This study provides evidence that X. muta in southeast Florida can naturally recover. Details on sponge size class associated recovery processes and growth were not collected due to event associated legal issues limiting the study. Studies to determine detailed growth rates and recovery success for different injury and restoration scenarios will further facilitate restoration decision making by resource managers

    A characterization of a Southeast Florida stony coral assemblage after a disease event

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    Coral reefs have declined globally due to anthropogenic stressors increasing the frequency and severity of bleaching and disease events. In 2014, a stony coral tissue loss disease (SCTLD) outbreak occurred off the coast of southeast Florida and subsequently spread throughout the region. Data collected by the Southeast Florida Reef Evaluation and Monitoring Project (SECREMP) were used to examine the regional impacts of the disease event on the Southeast Florida stony coral assemblage. A long-term annual monitoring project, SECREMP samples permanent sites along the Southeast Florida Reef Tract (SEFRT) from Miami-Dade County north to Martin County. Analysis of stony coral demographic data from 21 sites revealed regional SCTLD prevalence increased significantly, and significant region-wide declines in stony coral diversity and density were observed. From 2014 to 2018, species-specific susceptibility to the disease were evident, with Meandrina meandritesand Dichocoenia stokesiboth losing \u3e 90% of all live tissue by 2016. The reef building, complexity-contributing species Montastraea cavernosaand Orbicellaspp. lost significant tissue (55% and 70% respectively) as a result of this disease event. Overall, up to 64% of all live tissue was lost and at least 11 of 28 total species were impacted by SCTLD. Of the colonies that suffered complete mortality, many were among the largest individuals in the dataset. Loss of large, sexually mature colonies lowers reproductive capabilities and thus severely inhibits the potential for recovery. Juvenile surveys showed many of the large, structurally complex species had little to no juveniles within the sample sites, while eurytopic generalist species made up more than 76% of all juveniles. This disease event resulted in acute mortality and altered ecosystem function to the point where recovery is uncertain. To facilitate recovery, local resource managers need to understand the severity of the disease outbreak on the coral assemblage and mitigate local anthropogenic stressors

    The biology and fishery of Atlantic sailfish Istiophorus platypterus from southeast Florida

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    (Document has 31 pages.

    Analysis of Factors Influencing Southeast Florida Coral Reef Community Composition

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    The southeast Florida reef system lies offshore a heavily populated and urbanized coast. These high latitude reefs are not only affected by their geography but also by anthropogenic factors that accompany an urban area such as dredging activities, ship groundings, waste water outfalls, runoff and beach erosion. Sedimentation has been shown to influence stony coral community composition including dominance, abundance, cover, diversity, and colony size. Using annual monitoring data collected since 2000, the southeastern Florida reef community is being analyzed to examine if and how sedimentation and other factors such as depth, distance from shore and distance from port channels might influence community composition. All data was collected by SCUBA divers conducting 30m2 belt transect surveys at 24 sites offshore Broward County (southeast), Florida within a depth range of 6 to 18 meters. Stony coral data included colony size, abundance, diversity, percent cover, and mortality. Sponge and octocoral density were collected to gather a more complete picture of community composition. Three sediment bottles at each annually monitored site were collected every 60 days. Weight and grain size of the contents were analyzed and used to determine sedimentation rates at each site. Additionally, the reefs off the southeast Florida coast can be categorized into unique habitat types. These habitat types are also being considered when studying reef community composition and its relationship to sedimentation and other factors
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