998 resultados para Coral lagoons,


Relevância:

20.00% 20.00%

Publicador:

Resumo:

The offshore shelf and canyon habitats of the OCNMS are areas of high primary productivity and biodiversity that support extensive groundfish fisheries. Recent acoustic surveys conducted in these waters have indicated the presence of hard-bottom substrates believed to harbor unique deep-sea coral and sponge assemblages. Such fauna are often associated with shallow tropical waters, however an increasing number of studies around the world have recorded them in deeper, cold-water habitats in both northern and southern latitudes. These habitats are of tremendous value as sites of recruitment for commercially important fishes. Yet, ironically, studies have shown how the gear used in offshore demersal fishing, as well as other commercial operations on the seafloor, can cause severe physical disturbances to resident benthic fauna. Due to their exposed structure, slow growth and recruitment rates, and long life spans, deep-sea corals and sponges may be especially vulnerable to such disturbances, requiring very long periods to recover. Potential effects of fishing and other commercial operations in such critical habitats, and the need to define appropriate strategies for the protection of these resources, have been identified as a high-priority management issue for the sanctuary.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This Freely Associated States Shallow-water Coral Ecosystem Mapping Implementation Plan (FAS MIP) presents a framework for the development of shallow-water (~0–40 m; 0–22 fm) benthic habitat and possibly bathymetric maps of critical areas of the Freely Associated States (FAS). The FAS is made up of three self-governing groups of islands and atolls—the Republic of Palau (Palau), the Federated States of Micronesia (FSM), and the Republic of the Marshall Islands (RMI)—that are affiliated with the United States through Compacts of Free Association. This MIP was developed with extensive input from colleges, national and state regulatory and management agencies, federal agencies, non-governmental organizations, and individuals involved in or supporting the conservation and management of the FAS’s coral ecosystems. A list of organizations and individuals that provided input to the development of this MIP is provided in Appendix 1. This MIP has been developed to complement the Coral Reef Mapping Implementation Plan (2nd Draft) released in 1999 by the U.S. Coral Reef Task Force’s Mapping and Information Synthesis Working Group. That plan focused on mapping United States and FAS shallow-water (then defined as <30 m) coral reefs by 2009, based on available funding and geographic priorities, using primarily visual interpretation of aerial photography and satellite imagery. This MIP focuses on mapping the shallow-water (now defined as 0–40 m, rather than 0–30 m) coral ecosystems of the FAS using a suite of technologies and map development procedures. Both this FAS MIP and the 1999 Coral Reef Mapping Implementation Plan (2nd Draft) support to goals of the National Action Plan to Conserve Coral Reefs (U.S. Coral Reef Task Force, 2000). This FAS MIP presents a framework for mapping the coral ecosystems of the FAS and should be considered an evolving document. As priorities change, funding opportunities arise, new data are collected, and new technologies become available, the information presented herein will change.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The Southern Florida Shallow-water Coral Ecosystem Mapping Implementation Plan (MIP) discusses the need to produce shallow-water (~0-40 m; 0-22 fm) benthic habitat and bathymetric maps of critical areas in southern Florida and moderate-depth (~40-200 m; 22 -109 fm) bathymetric maps for all of Florida. The ~0-40 m depth regime generally represents where most hermatypic coral species are found and where most direct impacts from pollution and coastal development occur. The plan was developed with extensive input from over 90 representatives of state regulatory and management agencies, federal agencies, universities, and non-governmental organizations involved in the conservation and management of Florida’s coral ecosystems. Southern Florida’s coral ecosystems are extensive. They extend from the Dry Tortugas in the Florida Keys as far north as St Lucie Inlet on the Atlantic Ocean coast and Tarpon Springs on the Gulf of Mexico coast. Using 10 fm (18 m) depth curves on nautical charts as a guide, southern Florida has as much as 84 percent (30,801 sq km) of 36,812 sq km of potential shallow-water (<10 fm; <18 m) coral ecosystems the tropical and subtropical U.S. Moreover, southern Florida’s coral ecosystems contribute greatly to the regional economy. Coral ecosystem-related expenditures generated $4.4 billion in sales, income, and employment and created over 70,000 full-time and part-time jobs in the region during the recent 12-month periods when surveys were conducted.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Coral bleaching is a significant contributor to the worldwide degradation of coral reefs and is indicative of the termination of symbiosis between the coral host and its symbiotic algae (dinoflagellate; Symbiodinium sp. complex), usually by expulsion or xenophagy (symbiophagy) of its dinoflagellates. Herein, we provide evidence that during the earliest stages of environmentally induced bleaching, heat stress and light stress generate distinctly different pathomorphological changes in the chloroplasts, while a combined heat- and light-stress exposure induces both pathomorphologies; suggesting that these stressors act on the dinoflagellate by different mechanisms. Within the first 48 hours of a heat stress (32°C) under low-light conditions, heat stress induced decomposition of thylakoid structures before observation of extensive oxidative damage; thus it is the disorganization of the thylakoids that creates the conditions allowing photo-oxidative-stress. Conversely, during the first 48 hours of a light stress (2007 µmoles m−2 s−1 PAR) at 25°C, condensation or fusion of multiple thylakoid lamellae occurred coincidently with levels of oxidative damage products, implying that photo-oxidative stress causes the structural membrane damage within the chloroplasts. Exposure to combined heat- and light-stresses induced both pathomorphologies, confirming that these stressors acted on the dinoflagellate via different mechanisms. Within 72 hours of exposure to heat and/or light stresses, homeostatic processes (e.g., heat-shock protein and anti-oxidant enzyme response) were evident in the remaining intact dinoflagellates, regardless of the initiating stressor. Understanding the sequence of events during bleaching when triggered by different environmental stressors is important for predicting both severity and consequences of coral bleaching

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Scientific and anecdotal observations during recent decades have suggested that the structure and function of the coral reef ecosystems around St. John, U.S. Virgin Islands have been impacted adversely by a wide range of environmental stressors. Major stressors included the mass die-off of the long-spined sea urchin (Diadema antillarum) in the early 1980s, a series of hurricanes (David and Frederick in 1979, and Hugo in 1989), overfishing, mass mortality of Acropora species and other reef-building corals due to disease and several coral bleaching events. In response to these adverse impacts, the National Centers for Coastal Ocean Science (NCCOS), Center for Coastal Monitoring and Assessment, Biogeography Branch (CCMA-BB) collaborated with federal and territorial partners to characterize, monitor, and assess the status of the marine environment around the island from 2001 to 2012. This 13-year monitoring effort, known as the Caribbean Coral Reef Ecosystem Monitoring Project (CREM), was supported by the NOAA Coral Reef Conservation Program as part of their National Coral Reef Ecosystem Monitoring Program. This technical memorandum contains analysis of nine years of data (2001-2009) from in situ fish belt transect and benthic habitat quadrat surveys conducted in and around the Virgin Islands National Park (VIIS) and the Virgin Islands Coral Reef National Monument (VICR). The purpose of this document is to: 1) Quantify spatial patterns and temporal trends in (i) benthic habitat composition and (ii) fish species abundance, size structure, biomass, and diversity; 2) Provide maps showing the locations of biological surveys and broad-scale distributions of key fish and benthic species and assemblages; and 3) Compare benthic habitat composition and reef fish assemblages in areas under NPS jurisdiction with those in similar areas not managed by NPS (i.e., outside of the VIIS and VICR boundaries). This report provides key information to help the St. John management community and others understand the impacts of natural and man-made perturbations on coral reef and near-shore ecosystems. It also supports ecosystem-based management efforts to conserve the region’s coral reef and related fauna while maintaining the many goods and ecological services that they offer to society.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

NOAA’s National Centers for Coastal Ocean Science Biogeography Branch has mapped and characterized large portions of the coral reef ecosystems inside the U.S. coastal and territorial waters, including the U.S. Caribbean. The complementary protocols used in these efforts have enabled scientists and managers to quantitatively and qualitatively compare marine ecosystems in tropical U.S. waters. The Biogeography Branch used similar protocols to generate new benthic habitat maps for Fish Bay, Coral Bay and the St. Thomas East End Reserve (STEER). While this mapping effort marks the third time that some of these shallow-water habitats (≤40 m) have been mapped, it is the first time that nearly 100% of the seafloor has been characterized in each of these areas. It is also the first time that high resolution imagery describing seafloor depth has been collected in each of these areas. Consequently, these datasets provide new information describing the distribution of coral reef ecosystems and serve as a spatial baseline for monitoring change in the Fish Bay, Coral Bay and the STEER. Benthic habitat maps were developed for approximately 64.3 square kilometers of seafloor in and around Fish Bay, Coral Bay and the STEER. Twenty seven percent (17.5 square kilometers) of these habitat maps describe the seafloor inside the boundaries of the STEER, the Virgin Islands National Park and the Virgin Islands Coral Reef National Monument. The remaining 73% (46.8 square kilometers) describe the seafloor outside of these MPA boundaries. These habitat maps were developed using a combination of semi-automated and manual classification methods. Habitats were interpreted from aerial photographs and LiDAR (Light Detection and Ranging) imagery. In total, 155 distinct combinations of habitat classes describing the geology and biology of the seafloor were identified from the source imagery.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

NOAA’s National Centers for Coastal Ocean Science (NCCOS)-Center for Coastal Monitoring and Assessment’s (CCMA) Biogeography Branch, National Park Service (NPS), US Geological Survey, and the University of Hawaii used acoustic telemetry to quantify spatial patterns and habitat affinities of reef fishes around the island of St. John, US Virgin Islands. The objective of the study was to define the movements of reef fishes among habitats within and between the Virgin Islands Coral Reef National Monument (VICRNM), the Virgin Islands National Park (VIIS), and Territorial waters surrounding St. John. In order to better understand species’ habitat utilization patterns among management regimes, we deployed an array of hydroacoustic receivers and acoustically tagged reef fishes. Thirty six receivers were deployed in shallow near-shore bays and across the shelf to depths of approximately 30 m. One hundred eighty four individual fishes were tagged representing 19 species from 10 different families with VEMCO V9-2L-R64K transmitters. The array provides fish movement information at fine (e.g., day-night and 100s meters within a bay) to broad spatial and temporal scales (multiple years and 1000s meters across the shelf). The long term multi-year tracking project provides direct evidence of connectivity across habitat types in the seascape and among management units. An important finding for management was that a number of individuals moved among management units (VICRNM, VINP, Territorial waters) and several snapper moved from near-shore protected areas to offshore shelf-edge spawning aggregations. However, most individuals spent the majority of their time with VIIS and VICRNM, with only a few wide-ranging species moving outside the management units. Five species of snappers (Lutjanidae) accounted for 31% of all individuals tagged, followed by three species of grunts (Haemulidae) accounting for an additional 23% of the total. No other family had more than a single species represented in the study. Bluestripe grunt (Haemulon sciurus) comprised 22% of all individuals tagged, followed by lane snappers (Lutjanus synagris) at 21%, bar jack (Carangoides ruber) at 11%, and saucereye porgy (Calamus calamus) at 10%. The largest individual tagged was a 70 cm TL nurse shark (Ginglymostoma cirratum), followed by a 65 cm mutton snapper (Lutjanus analis), a 47 cm bar jack, and a 41 cm dog snapper (Lutjanus jocu). The smallest individuals tagged were a 19 cm blue tang (Acanthurus coeruleus) and a 19.2 cm doctorfish (Acanthurus chirurgus). Of the 40 bluestriped grunt acoustically tagged, 73% were detected on the receiver array. The average days at large (DAL) was 249 (just over 8 months), with one individual detected for 930 days (over two and a half years). Lane snapper were the next most abundant species tagged (N = 38) with 89% detected on the array. The average days at large (DAL) was 221 with one individual detected for 351 days. Seventy-one percent of the bar jacks (N = 21) were detected on the array with the average DALs at 47 days. All of the mutton snapper (N = 12) were detected on the array with an average DAL of 273 and the longest at 784. The average maximum distance travelled (MDT) was ca. 2 km with large variations among species. Grunts, snappers, jacks, and porgies showed the greatest movements. Among all individuals across species, there was a positive and significant correlation between size of individuals and MDT and between DAL and MDT.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Digital maps of the coral reef ecosystem (<~30m deep) of Majuro Atoll, Republic of the Marshall Islands, were created through visual interpretation of remote sensing imagery. Digital Globe’s Quickbird II satellite images were acquired between 2004 and 2006 and georeferenced to within 1.6 m of their true positions. Reef ecosystem features were digitized directly into a GIS at a display scale of 1:4000 using a minimum feature size of 1000 square meters. Benthic features were categorized according to a classification scheme with attributes including zone (location, such as lagoon or forereef, etc.), structure (bottom type, such as sand or patch reef, etc.) and percent hard bottom. Ground validation of habitat features was conducted at 311 sites in 2009. Resulting maps consisted of 1829 features covering 366 square kilometers. Results demonstrate that reef zones occurred in a typical progression of narrow bands from offshore, though forereef, reef flat, shoreline, land, backreef, and lagoon habitats. Lagoon was the largest zone mapped and covered nearly 80% of the atoll, although much of it was too deep to have structures identified from the satellite imagery. Dominant habitat structures by area were pavement and aggregate reef, which covered 29% and 18% of the mapped structures, respectively. Based on the number of features, individual and aggregated patch reefs comprised over 40% of the features mapped. Products include GIS based maps, field videos and pictures, satellite imagery, PDF atlas, and this summary report. Maps and associated data can be used to support science and management activities on Majuro reef ecosystems including inventory, monitoring, conservation, and sustainable development applications.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Coral reef ecosystems are some of the most complex and important ecosystems in the marine environment. They are also among the most biologically diverse and economically valuable ecosystems on earth, producing billions of dollars in food, as well as providing a suite of ecological services, such as recreation and tourism activities and coastal protection from storm and wave action. Yet, despite their value and importance, these fragile ecosystems are declining at an alarming rate (Waddell and Clarke (eds.) 2008) due to a myriad of threats both natural and manmade, including climate change, fishing pressure, and runoff and sedimentation. In response, the Unites States Coal Reef Task Force was established in 1998 by Presidential Executive Order 13089 to lead U.S. efforts to preserve and protect the nation’s coral reef ecosystems. In order to better understand the current state of coral reef ecosystems and successfully mitigate the impacts of stressors, informational products, such as benthic (or sea floor) habitat maps, are critical. Benthic habitat maps support the ability to prioritize areas for further study and protection, and offer a baseline to evaluate the changes in ecosystems over time. In 2000, the United States Coral Reef Task Force charged NOAA with leading federal efforts to produce comprehensive digital maps of all U.S. shallow-water (approximately 0 to 30 m in depth) coral reef ecosystem habitats.