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1.
The Florida Keys National Marine Sanctuary is a large, multiple-use marine protected area, including a network of fully protected marine zones, which was designated in 1990 to protect the coral reef ecosystem surrounding the Florida Keys. The South Florida Ecosystem Restoration (SFER) Initiative was formed in 1993 to restore more natural flows to the ecosystem, restore and enhance the natural system, and transform the built environment. These two large-scale efforts at ecosystem-based management are tightly linked, albeit asymmetrically because of the importance of restored flows of pure fresh water across the Everglades and into the coastal ecosystem. The growing population of South Florida, combined with increasing development, agriculture, and other human activities, imperils the entire South Florida ecosystem, from the headwaters of Lake Okeechobee to the Florida Reef Tract. This paper presents the evolution and characteristics of the Florida Keys National Marine Sanctuary and the SFER Initiative, which have both been tasked with addressing complex issues regarding ecosystem-based management. Key linkages between these programs involve connectivity, both physical and human, through circulation patterns and exchange processes in South Florida coastal waters and through the complex bureaucracy that has grown to manage human uses of natural resources.  相似文献   

2.
The Florida Keys National Marine Sanctuary (FKNMS) developed a zoning plan as part of its overall management plan, fully implemented as of 1997. The plan created several closed areas or harvest refugia in which consumptive activities are prohibited. This research reports results of surveys that we conducted with members of three stakeholder groups in the Florida Keys: commercial fishers, dive operators, and members of local environmental groups. Surveys requested responses regarding the information sources individuals tapped when learning of the zoning plan and the FKNMS; their degree of public participation; their perceptions and acceptance of the zoning strategy and the process of its design; and the expected outcomes of the zoning strategy. Many responses show significant differences among the three groups. Fishers felt highly alienated from the process of zone designation and displayed a sense of anger and powerlessness with respect to what they considered to be an attempt to exclude their group from the harvest refugia. Dive operators demonstrated the highest levels of participation in the designation process, but were concerned that refugia regulations could limit their activities in the future. Members of environmental groups were the strongest supporters of the harvest refugia concept and the FKNMS. This research suggests numerous ways in which marine resource managers could improve their public outreach and information dissemination strategies when developing future harvest refugia and marine protected areas.  相似文献   

3.
Preservation of marine habitats and water quality is paramount to the future economy of the Florida Keys. The Florida Keys National Marine Sanctuary (FKNMS) together with Monroe County have coordinated their actions to protect benthic habitats, improve water quality in the Sanctuary, and implement stormwater and wastewater infrastructure. Cooperation between the Sanctuary and Monroe County has resulted in the creation of No-Discharge Zones and public works projects both of which have succeeded in reducing pollutants into Sanctuary waters. Efforts to improve communication between the Sanctuary and County should still be made in order for improvements in water quality to be realized.  相似文献   

4.
Geotechnical characteristics of carbonate sediments from two test sites (Dry Tortugas Keys and Marquesas Keys) in the Lower Florida Keys were investigated as part of the Coastal Benthic Boundary Layer Special Research Program, through an extensive field coring and laboratory testing program conducted by the Marine Geomechanics Laboratory of the University of Rhode Island. Based on results from physical measurements, water content and wet bulk density values for both sites generally showed large variations in the upper 25 cm and little variation below this depth. Sediment samples exhibited low plasticity or nonplastic characteristics. Constant-rate-of-deformation consolidation test results showed strong apparent overconsolidation (stress state ratio >7.5) in the surface sediments (upper 50 cm) at the Dry Tortugas Keys, and light overconsolidation (stress state ratio <1.5) below 50-cm depth at the Marquesas Keys site. In-situ permeability values were between 10-4 and 10-7 cm/s at both sites and showed no strong depth dependence in the upper 2 m. Undrained shear strength profiles for Dry Tortugas Keys sediments indicated a marked stiffening with depth, whereas the Marquesas Keys sediments showed a gradual increase with depth. Consolidated isotropically undrained triaxial shear strength test results indicate that the undisturbed sediments had an average effective angle of internal friction of 38°, which is not fully realized until large axial strains on the order of 11% have accumulated. Evidence of cementation was not found in triaxial compression or consolidation test results. The general behavior and characteristics of these sediments are similar to those of granular materials, which is primarily due to their high calcium carbonate contents and lack of cementation.  相似文献   

5.
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6.
The decline of the world's fisheries and the inability of traditional management frameworks to maintain them, has led managers to adopt alternative management frameworks. The use of dedicated access privileges have often been shown to have varying popularity among factions within the commercial fishing industry and managers. Here, we examine commercial fishers' preference for alternative management frameworks in the context of a unique multispecies fisheries of the Florida Keys. By surveying commercial fishers, we find that that the size of operation plays no role in affecting fisher perception regarding dedicated access privileges. Furthermore, fishers who are organized are less likely to support dedicated access privilege frameworks. Overall, we do not find enough support in the fishing industry for the implementation of dedicated access privileges in the Florida Keys. These findings can provide inputs in developing effective management plans in the region.  相似文献   

7.
 This special issue of Geo-Marine Letters, “Benthic Boundary Layer Processes in the Lower Florida Keys,” includes 12 papers that present preliminary results from the Key West Campaign. The Dry Tortugas and Marquesas Keys test sites were selected by a group of 115 scientists and technicians to study benthic boundary layer processes in a carbonate environment controlled by bioturbation and biogeochemical processes. Major activities included remote sediment classification; high-frequency acoustic scattering experiments; sediment sampling for radiological, geotechnical, biological, biogeochemical, physical, and geoacoustic studies; and hydrodynamic studies using an instrumented tetrapod. All these data are being used to improve our understanding of the effects of environmental processes on sediment structure and behavior.  相似文献   

8.
Recent studies have demonstrated that sponge‐eating fishes alter the community of sponges on coral reefs across the Caribbean. Sponge species that lack chemical defenses but grow or reproduce faster than defended species are more abundant on reefs where sponge‐eating fishes have been removed by overfishing. Does predator‐removal have an effect on the distribution of sponges at smaller spatial scales? We conducted transect surveys of sponge species that are palatable to sponge predators in proximity to refuge organisms that are chemically or physically defended (fire coral, gorgonians, hard corals) on the heavily overfished reefs of Bocas del Toro, Panama, and a reef in the Florida Keys where sponge‐eating fishes are abundant. In Panama, palatable sponge species were not distributed in close association with refuge organisms, while in the Florida Keys, palatable sponge species were strongly associated with refuge organisms. The presence of fish predators alters the meter‐scale pattern of sponge distribution, and defense by association enhances biodiversity by allowing palatable sponges to persist on reefs where sponge‐eating fishes are abundant.  相似文献   

9.
Stochastic Events and Dynamics of a Mangrove Root Epifaunal Community   总被引：2，自引：0，他引：2  
Abstract. Submerged roots of red mangroves ( Rhizophora mangle ) in the Florida Keys were photographed at 1– or 2-month intervals for 38 months to measure population dynamics of the epifaunal invertebrate species. Photographs were analysed for species composition and abundance and information on life spans, persistence, mortality, and seasonality. Larval recruitment to artificial surfaces was used to assess reproductive seasonality. As a measure of stability, populations were tested for narrow stochastic boundedness.
In contrast to reports for a tropical mangrove root community, the Florida Keys root community showed enormous variability despite being dominated by long-lived species with low, largely non-seasonal recruitment. Species composition on individual roots changed dramatically on short time scales. Populations of the major species were not narrowly bounded on most roots and there was little evidence for a closely regulated community.
Variability of this community related to the frequency and intensity of stochastic perturbations. Physical disturbance due to strong tidal Rows appeared to be the most important structuring process. Species-specific predation and fragmentation of sponges were also important. These features contribute to the instability of the community by producing dramatic fluctuations in species abundances and preventing competitive processes from producing a more stable, equilibrium community. Temporal measurement scale was an additional important consideration in this habitat. Structuring processes occurred on very short time scales (1–2 months) and analysis on longer time scales gave inaccurate impressions of community dynamics.  相似文献   

10.
Recent observations using moored current meters, shipboard ADCP transects, salinity mapping and drifters have been used to study the residual circulation including wind drift in western Florida Bay.Rapid, nearly synoptic surveys of salinity over a large area was an effective tracer-mapping technique, when salinity gradients were sufficiently strong, and provided qualitative information on Lagrangian water motion for the entire study area. The salinity maps indicated a general south-eastward advection, which was only subordinate to tidal mixing in a narrow zone adjacent to the Florida Keys.Drifter data collected simultaneously, allowed quantitative estimates to be added to the transport pattern suggested by salinity maps. The selectively deployed drifters yielded estimates of total drift velocities. In addition, moored current meters and shipboard current profiling were used to determine the distribution of flow across the mouth of the bay facing the Gulf of Mexico and the transport through Long Key Channel, a major connection between the bay and the Atlantic Ocean.Analysis showed that from 64 to over 92% of the drifter trajectory variances could be explained by the combination of a local wind drift, expressed in terms of a wind drift factor multiplied by the surface shear velocity, and an ambient current. For a 1 m high drifter deployed at the surface of the water column, the wind drift factor was found to be approximately 0·125m, making the drift speed roughly equal to 0·45% of wind speed. The mean drifter speeds were linearly proportional to mean transport estimates derived from the current meter observations in Long Key Channel, enhancing confidence in both data sets.The total south-eastward directed residual current varied between 100 and 5000 m day−1and was weaker in summer than in winter, when southward winds associated with periodic passage of cold fronts boost the residual flow. The estimated contribution from local wind drift varied between 500 m day−1in summer to 1000 m day−1in winter. The remaining contribution to the observed Lagrangian residual circulation in western Florida Bay is caused by other forcing, including tidal rectification, remote wind forcing and large-scale current systems (the Gulf Stream and Florida Current systems).  相似文献   

11.
 Between 2 and 6 February, 1995, a 25 km2 area at the Dry Tortugas (Florida Keys) was surveyed with a 100 kHz side-scan sonar system and 3.5-kHz subbottom profiler. The side-scan system revealed a pattern of alternating high and low backscatter. The subbottom profiler showed areas with no acoustic penetration between sediment troughs. The combination of both methods allowed delineation of the boundaries in high-backscatter regions, and sediment samples allowed correlations between high backscatter and coarser-grained sediments.  相似文献   

12.
In the absence of consensus on the quantity and level of zoning protection required for coral reef and lagoon ecosystems, which process can guide decision makers? The Great Barrier Reef Marine Park Authority (GBRMPA) worked with experts in a collaborative process to develop a set of Biophysical Operational Principles to guide the design of a network of no-take areas. First, 82 expert scientists were asked to provide data and advice on the physical, biological and ecological dimensions of the Great Barrier Reef ecosystem. They recommended that an independent Scientific Steering Committee (the Committee) was set up. How this Committee worked successfully with the GBRMPA staff is detailed here in a manner to enable other resource managers to adopt the process if they are working in data-limited marine environments.  相似文献   

13.
《Ocean & Coastal Management》2006,49(3-4):164-187
The Netherlands is considering large-scale offshore sand extraction to meet the increasing demand for building sand, as the current supply of sand from land is insufficient. To develop a well-considered management policy to address this problem, knowledge about future morphological changes offshore caused by such an extraction is necessary. Such knowledge is not yet available. To support decisions about large-scale sand extraction, we developed a morphological model, which indicates possible effects of such extraction. However, because no field data is available, we cannot meet the requirement of decision makers to validate this model. Therefore, its results are controversial and difficult to use in decision-making. In this study, firstly we evaluate whether validation of the model would help the decision-making process about large-scale sand extraction? Secondly, we explore how we can use the invalidated model results in decision-making. And finally, we explore how to improve both the model and the use of the model without validation.Our opinion is that validation of the model will not solve the problem that decision makers deal with, and that although invalidated, decision makers can use the model results by using them as early warning signals. Interviews with the key players, to define the willingness to use the model results for decision-making, lead to useful recommendations to improve the model. These interviews were the first step of constructive technology assessment (CTA), which focuses on broadening the design and implementation process to stimulate the integration of societal criteria in the development of the model. Besides, these interviews appeared to have a positive influence on the willingness of the key players to use the model for decision-making. In general, we conclude that CTA, modulating the interaction between model and decision process, is a useful method for model makers that can help to make their models useful tools for decision-making.  相似文献   

14.
Populations of continuously distributed marine organisms that disperse via pelagic larvae are often assumed to exist in a state of genetic panmixia because of their potential ability for long‐distance dispersal. However, obligate symbionts may have more restricted gene flow due to recruitment limitations, making host specificity an important potential driver of biodiversity. To explore the tension between broad dispersal ability and limited recruitment potential, we used sequences of mtDNA cytochrome c oxidase subunit I (COI) to assess the fine‐scale phylogeography of the cleaner shrimp, Ancylomenes pedersoni, an obligate symbiont of sea anemones, along 300 km of the Florida Reef Tract (FRT). The results indicate high genetic diversity within A. pedersoni populations along the FRT. Pair‐wise ?ST values indicate significant genetic structuring between northern (Fort Lauderdale and Upper Keys) and southwestern (Lower Keys) populations, with significant isolation by distance. Two divergent COI haplotype lineages were detected through statistical parsimony analysis: one evenly distributed across the entire FRT (Clade 1) and one found primarily in two sample localities in the Lower Keys (Clade 2). Phylogenetic analyses using 16S‐rDNA indicates that this genetic diversity is of paraphyletic origin, and possibly the result of multiple colonization events. These results reveal a complex demographic and evolutionary history for A. pedersoni populations and provide the first evidence of highly divergent intra‐specific lineages independently colonizing the FRT. Because the FRT is a highly impacted coral reef system, understanding phylogeographic patterns along it has value beyond documentation of the factors that generate genetic diversity in tropical reef systems: these data are critical for creating scientifically based management strategies.  相似文献   

15.
 Functional group analysis was used to determine the major bioturbators in the Dry Tortugas, Florida Keys. The surface community is dominated by surface deposit feeding polychaetes and burrowing bivalves capable of mixing the top 0–4 cm of the sediment on time scales of days to weeks. Bioturbation by the Notomastus sp. and Callianassa sp. deep community effectively removes primary sedimentary structures. Their fossilized burrow structures may be geologically important in this system. Surface microtopography is controlled by stabilizing and destabilizing forces that determine the potential for surface resuspension and sediment transport in the Dry Tortugas.  相似文献   

16.
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17.
This paper develops a fuzzy pattern recognition model for group decision making to solve the problem of lectotype optimization of offshore platforms. The lack of data and the inexact or incomplete information for criteria are the main cause of uncertainty in the evaluation process, therefore it is necessary to integrate the judgments from different decision makers with different experience, knowledge and preference. This paper first uses a complementary principle-based pairwise comparison method to obtain the subjective weight of the criteria from each decision maker. A fuzzy pattern recognition model is then developed to integrate the judgments from all the decision makers and the information from the criteria, under the supervision of the subjective weights. Finally a case study is given to show the efficiency and robustness of the proposed model.  相似文献   

18.
Physical and biological processes controlling spatial and temporal variations in material concentration and exchange between the Southern Everglades wetlands and Florida Bay were studied for 2.5 years in three of the five major creek systems draining the watershed. Daily total nitrogen (TN), and total phosphorus (TP) fluxes were measured for 2 years in Taylor River, and ten 10-day intensive studies were conducted in this creek to estimate the seasonal flux of dissolved inorganic nitrogen (N), phosphorus (P), total organic carbon (TOC), and suspended matter. Four 10-day studies were conducted simultaneously in Taylor, McCormick, and Trout Creeks to study the spatial variation in concentration and flux. The annual fluxes of TOC, TN, and TP from the Southern Everglades were estimated from regression equations. The Southern Everglades watershed, a 460-km2 area that includes Taylor Slough and the area south of the C-111 canal, exported 7.1 g C m−2, 0.46 g N m−2, and 0.007 g P m−2, annually. Everglades P flux is three to four orders of magnitude lower than published flux estimates from wetlands influenced by terrigenous sedimentary inputs. These low P flux values reflect both the inherently low P content of Everglades surface water and the efficiency of Everglades carbonate sediments and biota in conserving and recycling this limiting nutrient. The seasonal variation of freshwater input to the watershed was responsible for major temporal variations in N, P, and C export to Florida Bay; approximately 99% of the export occurred during the rainy season. Wind-driven forcing was most important during the later stages of the dry season when low freshwater head coincided with southerly winds, resulting in a net import of water and materials into the wetlands. We also observed an east to west decrease in TN:TP ratio from 212:1 to 127:1. Major spatial gradients in N:P ratios and nutrient concentration and flux among the creek were consistent with the westward decrease in surface water runoff from the P-limited Everglades and increased advection of relatively P-rich Gulf of Mexico (GOM) waters into Florida Bay. Comparison of measured nutrient flux from Everglades surface water inputs from this study with published estimates of other sources of nutrients to Florida Bay (i.e. atmospheric deposition, anthropogenic inputs from the Florida Keys, advection from the GOM) show that Everglades runoff represents only 2% of N inputs and 0.5% of P input to Florida Bay.  相似文献   

19.
Local jurisdictions play a critical role in climate change mitigation and adaptation. This study analyzes the theoretical framework of locally driven climate change actions and uses geographic information system (GIS) to map local jurisdictions’ climate change policy efforts in three Pacific states - California, Oregon, and Washington. The results of our study indicate statistically significant differences in geographic clusters and variations across jurisdictions. An Ordinary Least Squares (OLS) regression model was used to examine climate risk, emission stress, and socioeconomic context variables to detect influence on local climate change policy efforts. The explanatory results indicate that coastal proximity, population density, vehicles emission, and education variables significantly influence local jurisdictions’ climate change actions. The findings contribute to local organizational decision model research and can help local communities to develop more effective climate change policies.  相似文献   

20.
Distribution of yttrium and rare earths in Florida Bay sediments   总被引：3，自引：1，他引：2  
The distribution of yttrium and rare earth elements (YREEs) in surface sediments was measured on samples collected from 40 stations in Florida Bay (June 2000 and February 2001). Florida Bay is the largest shallow carbonate estuary in South Florida with nearly pristine conditions. It receives fresh waters from some rivers and several canals from the Everglades which contribute rare earth elements and metals to the Bay. This paper is the first extensive study of YREEs in Florida Bay. Concentrations of YREEs (Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu) were determined by ICP-MS. The YREEs show a similar distribution pattern for the two months studied. The maximum concentrations were found in the western and north-central zones (near the Everglades) and the minimum concentrations were found in the south-central zone near the Florida Keys. The pattern of YREEs in Florida Bay sediments correlated strongly with those in the North American Shale Composite, indicating a dominant crustal source for these elements. However, the REE concentrations in Florida Bay sediments are depleted with respect to NASC. All REEs exhibited a strong correlation with Fe and Al from continental input and river runoff from the Everglades. The heavy REEs and Y showed a strong correlation with Al (R2 > 0.84). The light and medium REEs showed a strong correlation with Fe (R2 > 0.9). Correlations of all the YREEs with Mn were slightly lower (R2  0.7–0.75). The concentration of all the YREEs, Al and Fe are dependent on the bottom types and zones in the Bay, except Mn which decreases as it moves from the land to the sea.  相似文献   

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