991 resultados para Sand-lime products


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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.

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Marine protected areas (MPAs) represent a form of spatial management, and geospatial information on living marine resources and associated habitat is extremely important to support best management practices in a spatially discrete MPA. Benthic habitat maps provide georeferenced information on the geomorphic structure and biological cover types in the marine environment. This information supports an enhanced understanding of ecosystem function and species habitat utilization patterns. Benthic habitat maps are most useful for marine management and spatial planning purposes when they are created at a scale that is relevant to management actions. We sought to improve the resolution of existing benthic habitat maps created during a regional mapping effort in Hawai`i. Our results complemented these existing regional maps and provided more detailed, finer-scale habitat maps for a network of MPAs in West Hawai`i. The map products created during this study allow local planners and managers to extract information at a spatial scale relevant to the discrete management units, and appropriate for local marine management efforts on the Kona Coast. The resultant benthic habitat maps were integrated in a geographic information system (GIS) that also included aerial imagery, underwater video, MPA regulations, summarized ecological data and other relevant and spatially explicit information. The integration of the benthic habitat maps with additional “value added” geospatial information into a dynamic GIS provide a decision support tool with pertinent marine resource information available in one central location and support the application of a spatial approach to the management of marine resources. Further, this work can serve as a case study to demonstrate the integration of remote sensing products and GIS tools at a fine spatial scale relevant to local-level marine spatial planning and management efforts.

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For more than 25 years all sea turtle products have been prohibited from international commerce by the 170-member nations of the Convention on International Trade in Endangered Species (CITES). Sea turtles continue to be threatened by direct take (including poaching) and illegal trade despite multi-national protection efforts. Although take may contribute significantly to sea turtle decline, illegal take is difficult to measure since there are few quantified records associated with legal fisheries and fewer still for illegal take (poaching). We can, however, quantify one portion of the illegal sea turtle trade by determining how many illegal products were seized at United States ports of entry over a recent 10-year period. The United States Fish and Wildlife Service (USFWS) oversees the import and export of wildlife and wildlife products, ensuring that wildlife trade complies with United States laws and international treaties. Additionally, the USFWS has legal authority to target suspected illegal wildlife activity through undercover and field investigations. In an effort to assess the scale of illegal sea turtle take and trade, we have conducted a 10-year (1994 – 2003) review of the law enforcement database maintained by the USFWS. This database tracks the number and type of wildlife cases, the quantity of seized products, and the penalties assessed against violators. These data are minimum estimates of the sea turtle products passing through the United States borders, as smuggled wildlife is oftentimes not detected.

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Digital maps of the shallow (<~30m deep) coral reef ecosystems of Majuro Atoll, Republic of the Marshall Islands, were created through visual interpretation of remote sensing imagery acquired between 2004 and 2006. Reef ecosystem features were digitized directly into a Geographic Information System. 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. This atlas consists of 27 detailed maps displaying reef zone and structure of coral ecosystems around Majuro. Adjacent maps in the atlas overlap slightly to ensure complete coverage. Maps and associated products can be used to support science and management activities on Majuro reef ecosystems including inventory, monitoring, conservation, and sustainable development applications. Maps are not to be used for navigation.

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