998 resultados para Mingan Islands


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High elevation montane areas are called ``sky islands'' when they occur as a series of high mountains separated by lowland valleys. Different climatic conditions at high elevations makes sky islands a specialized type of habitat, rendering them naturally fragmented compared to more continuous habitat at lower elevations. Species in sky islands face unsuitable climate in the intervening valleys when moving from one montane area to another. The high elevation shola-grassland mosaic in the Western Ghats of southern India form one such sky island complex. The fragmented patches make this area ideal to study the effect of the spatial orientation of suitable habitat patches on population genetic structure of species found in these areas. Past studies have suggested that sky islands tend to have genetically structured populations, possibly due to reduced gene flow between montane areas. To test this hypothesis, we adopted the comparative approach. Using Amplified Fragment Length Polymorphisms, we compared population genetic structures of two closely related, similar sized butterfly species: Heteropsis oculus, a high elevation shola-grassland specialist restricted to the southern Western Ghats, and Mycalesis patnia, found more continuously distributed in lower elevations. In all analyses, as per expectation the sky island specialist H. oculus exhibited a greater degree of population genetic structure than M. patnia, implying a difference in geneflow. This difference in geneflow in turn appears to be due to the natural fragmentation of the sky island complexes. Detailed analysis of a subset of H. oculus samples from one sky island complex (the Anamalais) showed a surprising genetic break. A possible reason for this break could be unsuitable conditions of higher temperature and lower rainfall in the intervening valley region. Thus, sky island species are not only restricted by lack of habitat continuity between montane areas, but also by the nature of the intervening habitat.

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The M-w 8.6 and 8.2 strike-slip earthquakes that struck the northeast Indian Ocean on 11 April 2012 resulted in coseismic deformation both at near and distant sites. The slip distribution, deduced using seismic-wave analysis for the orthogonal faults that ruptured during these earthquakes, is sufficient to predict the coseismic displacements at the Global Positioning System (GPS) sites, such as NTUS, PALK, and CUSV, but fall short at four continuous sites in the Andaman Islands region. Slip modeling, for times prior to the events, suggests that the lower portion of the thrust fault beneath the Andaman Islands has been slipping at least at the rate of 40 cm/yr, in response to the 2004 Sumatra-Andaman coseismic stress change. Modeling of GPS displacements suggests that the en echelon and orthogonal fault ruptures of the 2012 intraplate oceanic earthquakes could have possibly accelerated the ongoing slow slip, along the lower portion of the thrust fault beneath the islands with a month-long slip of 4-10 cm. The misfit to the coseismic GPS displacements along the Andaman Islands could be improved with a better source model, assuming that no local process contributed to this anomaly.

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Background: Serovars of Salmonella enterica, namely Typhi and Typhimurium, reportedly, are the bacterial pathogens causing systemic infections like gastroenteritis and typhoid fever. To elucidate the role and importance in such infection, the proteins of the Type III secretion system of Salmonella pathogenicity islands and two component signal transduction systems, have been mainly focused. However, the most indispensable of these virulent ones and their hierarchical role has not yet been studied extensively. Results: We have adopted a theoretical approach to build an interactome comprising the proteins from the Salmonella pathogeneicity islands (SPI) and two component signal transduction systems. This interactome was then analyzed by using network parameters like centrality and k-core measures. An initial step to capture the fingerprint of the core network resulted in a set of proteins which are involved in the process of invasion and colonization, thereby becoming more important in the process of infection. These proteins pertained to the Inv, Org, Prg, Sip, Spa, Ssa and Sse operons along with chaperone protein SicA. Amongst them, SicA was figured out to be the most indispensable protein from different network parametric analyses. Subsequently, the gene expression levels of all these theoretically identified important proteins were confirmed by microarray data analysis. Finally, we have proposed a hierarchy of the proteins involved in the total infection process. This theoretical approach is the first of its kind to figure out potential virulence determinants encoded by SPI for therapeutic targets for enteric infection. Conclusions: A set of responsible virulent proteins was identified and the expression level of their genes was validated by using independent, published microarray data. The result was a targeted set of proteins that could serve as sensitive predictors and form the foundation for a series of trials in the wet-lab setting. Understanding these regulatory and virulent proteins would provide insight into conditions which are encountered by this intracellular enteric pathogen during the course of infection. This would further contribute in identifying novel targets for antimicrobial agents. (C) 2014 Elsevier Ltd. All rights reserved.

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Mangrove forests in meso-tidal areas are completely drained during low tides, forming only temporary habitats for fish. We hypothesised that in such temporary habitats, where stranding risks are high, distance from tidal creeks that provided access to inundated areas during receding tides would be the primary determinant of fish distribution. Factors such as depth, root density and shade were hypothesised to have secondary effects. We tested these hypotheses in a tidally drained mangrove patch in the Andaman Islands, India. Using stake nets, we measured fish abundance and species richness relative to distance from creeks, root density/m(2), shade, water depth and size (total length) of fish. We also predicted that larger fish (including potential predators) would be closer to creeks, as they faced a greater chance of mortality if stranded. Thus we conducted tethering trials to examine if predation would be greater close to the creeks. Generalised linear mixed effects models showed that fish abundance was negatively influenced by increasing creek distance interacting with fish size and positively influenced by depth. Quantile regression analysis showed that species richness was limited by increasing creek distance. Proportion of predation was greatest close to the creeks (0-25 m) and declined with increasing distance. Abundance was also low very close to the creeks, suggesting that close to the creeks predation pressure may be an important determinant of fish abundance. The overall pattern however indicates that access to permanently inundated areas, may be an important determinant of fish distribution in tidally drained mangrove forests.

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A new bufonid amphibian, belonging to a new monotypic genus, is described from the Andaman Islands, in the Bay of Bengal, Republic of India, based on unique external morphological and skeletal characters which are compared with those of known Oriental and other relevant bufonid genera. Blythophryne gen. n. is distinguished from other bufonid genera by its small adult size (mean SVL 24.02 mm), the presence of six presacral vertebrae, an absence of coccygeal expansions, presence of an elongated pair of parotoid glands, expanded discs at digit tips and phytotelmonous tadpoles that lack oral denticles. The taxonomic and phylogenetic position of the new taxon (that we named as Blythophryne beryet gen. et sp. n.) was ascertained by comparing its 12S and 16S partial genes with those of Oriental and other relevant bufonid lineages. Resulting molecular phylogeny supports the erection of a novel monotypic genus for this lineage from the Andaman Islands of India.

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Natural disasters pose a threat to isolated populations of species with restricted distributions, especially those inhabiting islands. The Nicobar long tailed macaque. Macaca fascicularis umbrosus, is one such species found in the three southernmost islands (viz. Great Nicobar, Little Nicobar and Katchal) of the Andaman and Nicobar archipelago, India. These islands were hit by a massive tsunami (Indian Ocean tsunami, 26 December 2004) after a 9.2 magnitude earthquake. Earlier studies Umapathy et al. 2003; Sivakumar, 2004] reported a sharp decline in the population of M. f. umbrosus after thetsunami. We studied the distribution and population status of M. f. umbrosus on thethree Nicobar Islands and compared our results with those of the previous studies. We carried out trail surveys on existing paths and trails on three islands to get encounter rate as measure of abundance. We also checked the degree of inundation due to tsunami by using Normalized Difference Water Index (NDWI) on landsat imageries of the study area before and after tsunami. Theencounter rate of groups per kilometre of M. f. umbrosus in Great Nicobar, Little Nicobar and Katchal was 0.30, 0.35 and 0.48 respectively with the mean group size of 39 in Great Nicobar and 43 in Katchal following the tsunami. This was higher than that reported in the two earlier studies conducted before and after the tsunami. Post tsunami, there was a significant change in the proportion of adult males, adult females and immatures, but mean group size did not differ as compared to pre tsunami. The results show that population has recovered from a drastic decline caused by tsunami, but it cannot be ascertained whether it has reached stability because of the altered group structure. This study demonstrates the effect of natural disasters on island occurring species.

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The Channel Islands—sometimes called the Galapagos of North America—are known for their great beauty, rich biodiversity, cultural heritage, and recreational opportunities. In 1980, in recognition of the islands’ importance, the United States Congress established a national park encompassing 5 of California’s Channel Islands (Santa Barbara, Anacapa, Santa Cruz, Santa Rosa, and San Miguel Islands) and waters within 1 nautical mile of the islands. In the same year, Congress declared a national marine sanctuary around each of these islands, including waters up to 6 nautical miles offshore. Approximately 60,000 people visit the Channel Islands each year for aquatic recreation such as fishing, sailing, kayaking, wildlife watching, surfing, and diving. Another 30,000 people visit the islands for hiking, camping, and sightseeing. Dozens of commercial fishing boats based in Santa Barbara, Ventura, Oxnard, and other ports go to the Channel Islands to catch squid, spiny lobster, sea urchin, rockfish, crab, sheephead, flatfish, and sea cucumber, among other species. In the past few decades, advances in fishing technology and the rising number of fishermen, in conjunction with changing ocean conditions and diseases, have contributed to declines in some marine fishes and invertebrates at the Channel Islands. In 1998, citizens from Santa Barbara and Ventura proposed establishment of no-take marine reserves at the Channel Islands, beginning a 4-year process of public meetings, discussions, and scientific analyses. In 2003, the California Fish and Game Commission designated a network of marine protected areas (MPAs) in state waters around the northern Channel Islands. In 2006 and 2007, the National Oceanic and Atmospheric Administration (NOAA) extended the MPAs into the national marine sanctuary’s deeper, federal waters. To determine if the MPAs are protecting marine species and habitats, scientists are monitoring ecological changes. They are studying changes in habitats; abundance and size of species of interest; the ocean food web and ecosystem; and movement of fish and invertebrates from MPAs to surrounding waters. Additionally, scientists are monitoring human activities such as commercial and recreational fisheries, and compliance with MPA regulations. This booklet describes some results from the first 5 years of monitoring the Channel Islands MPAs. Although 5 years is not long enough to determine if the MPAs will accomplish all of their goals, this booklet offers a glimpse of the changes that are beginning to take place and illustrates the types of information that will eventually be used to assess the MPAs’ effectiveness. (PDF contains 24 pages.)

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ENGLISH: The tendency of the tunas, especially the yellowfin (Neothunnus macropterus) to be more abundant in the near vicinity of islands and seamounts, or "banks", than in the surrounding oceanic areas, is well known to commercial fishermen. This has been confirmed by statistical analysis of fishing vessel logbook records, which demonstrates that the catch-per-day's-fishing is, indeed, higher in the near vicinity of these features. It is hypothesized that islands and seamounts cause changes in the physical circulation or the biochemical cycle resulting in greater supplies of food for tunas in their immediate environs. In order to examine this hypothesis, and in order to study possible mechanisms involved, the "Island Current Survey" was undertaken from 8 May to 12 June, 1957, under the joint auspices of the Inter-American Tropical Tuna Commission and the Scripps Institution of Oceanography. Surveys of varying nature and extent were made from M/V Spencer F. Baird near Alijos Rocks, Clarion Island, Shimada Bank and Socorro Island (Figure 1). These studies sought to provide knowledge of the action of islands and seamounts in arresting, stalling or deflecting the mean current past them, in establishing convergence and divergence in the surface flow, in producing vertical motion (mixing and upwelling), and in influencing the primary production and the standing crops of phytoplankton and zooplankton. Each survey is discussed below in detail. Observations made at a front on 10 June will be discussed in another paper. SPANISH: Los pescadores que realizan la pesca comercial conocen muy bien la tendencia de los atunes, en particular del atún aleta amarilla (Neothunnus macropterus), de presentarse en mayor abundancia en las cercanías inmediatas a las islas y cimas submarinas, o "bancos", que en las áreas oceánicas circundantes. Este hecho ha sido confirmado par el análisis estadístico de los registros de los cuadernos de bitácora de las embarcaciones pesqueras, demostrándose que la captura par dias de pesca es, en efecto, más abundante en la inmediata proximidad de tales formaciones. Hipotéticamente se admite que las islas y las cimas submarinas provocan cambios en la circulación física o en el ciclo bioquímico, lo cual se pone de manifiesto a través de un mejor abastecimiento de alimento para los atunes en sus cercanías inmediatas. Con la finalidad de verificar esta hipótesis y de estudiar los mecanismos que ella involucra, se realizó la “Island Current Survey” del 8 de mayo al 12 de junio de 1957, bajo los auspicios de la Comisión Interamericana del Atún Tropical y de la Institución Scripps de Oceanografia. Con el barco Spencer F. Baird se hicieron observaciones de distintas clases y alcances cerca de las Rocas Alijos, la Isla Clarion, el Banco Shimada y la Isla Socorro (Figura 1). Estos estudios tuvieron por objeto adquirir conocimientos sobre la acción que ejercen las islas y cimas submarinas sobre la corriente promedio, ya sea deteniéndola, reduciendo su velocidad o desviando su curso, así como estableciendo convergencia o divergencia en su flujo de superficie, o provocando un movimiento vertical (mezcla y afloramiento) e influyendo en la producción primaria y en las existencias de fitoplancton y zooplancton. Cada operación será tratada a continuación por separado. Las observaciones hechas el dia 10 de junio sobre un frente serán objeto de otra publicación.

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Research cruises were conducted in August-October 2007 to complete the third annual remotely operated vehicle (ROV)-based assessments of nearshore rocky bottom finfish at ten sites in the northern Channel Islands. Annual surveys at the Channel Islands have been conducted since 2004 at four sites and were expanded to ten sites in 2005 to monitor potential marine protected area (MPA)effects on baseline fish density. Six of the ten sites are in MPAs and four in nearby fished reference areas. In 2007 the amount of soft-only substrate on the 141 track lines surveyed was again estimated in real-time in order to target rocky bottom habitat. These real-time estimates of hard and mixed substrate for all ten sites averaged 57%, 1% more than the post-processed average of 56%. Surveys generated 69.9 km of usable video for use in finfish density calculations, with target rocky bottom habitat accounting for 56% (39.1 km) for all sites combined. The amount of rocky habitat sampled by site averaged 3.8 km and ranged from 3.3 km sampled at South Point, a State Marine Reserve (SMR) off Santa Rosa Island, to 4.7 km at Anacapa Island SMR. A sampling goal of 75 transects at all 10 sites was met using real-time habitat estimates combined with precautionary over-sampling by 10%. A total of seventy kilometers of sampling is projected to produce at least seventy-five 100 m2 transects per site. Thirteen of 26 finfish taxa observed were selected for quantitative evaluation over the time series based on a minimum criterion of abundance (0.05/100 m2). Ten of these 13 finfish appear to be more abundant at the state marine reserves relative to fished areas when densities were averaged across the 2005 to 2007 period. One of the species that appears to be more abundant in fished areas was señorita, a relatively small prey species that is not a commercial or recreational target. (PDF contains 83 pages.)

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Since 1999, NOAA’s Biogeography Branch of the Center for Coastal Monitoring and Assessment (CCMA-BB) has been working with federal and territorial partners to characterize, monitor, and assess the status of the marine environment around northeastern St. Croix, U.S. Virgin Islands. This effort is part of the broader NOAA Coral Reef Conservation Program’s (CRCP) National Coral Reef Ecosystem Monitoring Program (NCREMP). With support from CRCP’s NCREMP, CCMA conducts the “Caribbean Coral Reef Ecosystem Monitoring project” (CREM) with goals to: (1) spatially characterize and monitor the distribution, abundance, and size of marine fauna associated with shallow water coral reef seascapes (mosaics of coral reefs, seagrasses, sand and mangroves); (2) relate this information to in situ fine-scale habitat data and the spatial distribution and diversity of habitat types using benthic habitat maps; (3) use this information to establish the knowledge base necessary for enacting management decisions in a spatial setting; (4) establish the efficacy of those management decisions; and (5) develop data collection and data management protocols. The monitoring effort in northeastern St. Croix was conducted through partnerships with the National Park Service (NPS) and the Virgin Islands Department of Planning and Natural Resources (VI-DPNR). The geographical focal point of the research is Buck Island Reef National Monument (BIRNM), a protected area originally established in 1961 and greatly expanded in 2001; however, the work also encompassed a large portion of the recently created St. Croix East End Marine Park (EEMP). Project funding is primarily provided by NOAA CRCP, CCMA and NPS. In recent decades, scientific and non-scientific observations have indicated that the structure and function of the coral reef ecosystem around northeastern St. Croix have been adversely impacted by a wide range of environmental stressors. The major stressors have included the mass Diadema die off in the early 1980s, a series of hurricanes beginning with Hurricane Hugo in 1989, overfishing, mass mortality of Acropora corals due to disease and several coral bleaching events, with the most severe mass bleaching episode in 2005. The area is also an important recreational resource supporting boating, snorkeling, diving and other water based activities. With so many potential threats to the marine ecosystem and a dramatic change in management strategy in 2003 when the park’s Interim Regulations (Presidential Proclamation No. 7392) established BIRNM as one of the first fully protected marine areas in NPS system, it became critical to identify existing marine fauna and their spatial distributions and temporal dynamics. This provides ecologically meaningful data to assess ecosystem condition, support decision making in spatial planning (including the evaluation of efficacy of current management strategies) and determine future information needs. The ultimate goal of the work is to better understand the coral reef ecosystems and to provide information toward protecting and enhancing coral reef ecosystems for the benefit of the system itself and to sustain the many goods and services that it offers society. This Technical Memorandum contains analysis of the first six years of fish survey data (2001-2006) and associated characterization of the benthos (1999-2006). The primary objectives were to quantify changes in fish species and assemblage diversity, abundance, biomass and size structure and to provide spatially explicit information on the distribution of key species or groups of species and to compare community structure inside (protected) versus outside (fished) areas of BIRNM. (PDF contains 100 pages).

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A literature review was conducted to locate information on the flow of energy from primary producers to the fishery stocks of the Puerto Rican-Virgin Islands insular shelf. This report uses site-specific information to describe the major ecological subsystems, or habitats, of the region, to identify the more common species and the subsystems in which they occur, to quantify productivity and biomass, and to outline trophic relationships. Discussions on each topic and subsystem vary in substance and detail, being limited by the availability and accessibility of information. (PDF contains 189 pages) Seven distinct subsystems are described: mangrove estuary, seagrass bed, coral reef, algal plain, sand/mud bottom, shelf break, and overlying pelagic. Over 50 tables provide lists of species found in each habitat on various surveys dating back to 1956. Estimates of density, relative abundance, and productivity are provided when possible. We evaluated whether sufficient information exists to support an analysis of the energy basis of fishery production in the area, beginning with the design and development of an ecosystem model. Data needs in three categories - species lists, biomass, and trophic relations - were examined for each subsystem and for each of three species groups - primary producers, invertebrates, and fish. We concluded that adequate data, sufficient for modeling purposes, are available in 16 (25%) of 64 categories; limited data, those requiring greater extrapolation, are available in 35 (55%) categories; and no data are available in 13 (20%) categories. The best-studied subsystems are seagrass beds and coral reefs, with at least limited data in all categories. Invertebrates, the intermediate link in the food web between primary producers and fishes, are the least quantified group in the region. Primary production and fishes, however, are relatively well-studied, providing sufficient data to support an ecosystem-level analysis and to initiate a modeling effort.

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The Scientific Forum on the Gulf of Mexico: The Islands in the Stream Concept took place in January 2008 in Sarasota, Florida. The purpose of the meeting was to bring together scientists and managers from around the Gulf of Mexico to discuss a range of topics on our knowledge of the Gulf of Mexico, from its geology to larger-scale connectivity to the Caribbean region, and their applications to the concept of a more integrated approach to area-based management. The forum included six panels of invited experts who spoke on the oceanographic and biological features in the Gulf of Mexico, including connections with Mexico and the Mesoamerican barrier reef system, and the legal and regulatory structure currently in place. The charge to the group was to share information, identify gaps in our knowledge, identify additional potential areas for protection, and discuss available science about connectivity and the potential value of establishing a marine protected area network in the Gulf of Mexico. (PDF has 108 pages.)