299 research outputs found

    Global Conservation Priorities for Marine Turtles

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    Where conservation resources are limited and conservation targets are diverse, robust yet flexible priority-setting frameworks are vital. Priority-setting is especially important for geographically widespread species with distinct populations subject to multiple threats that operate on different spatial and temporal scales. Marine turtles are widely distributed and exhibit intra-specific variations in population sizes and trends, as well as reproduction and morphology. However, current global extinction risk assessment frameworks do not assess conservation status of spatially and biologically distinct marine turtle Regional Management Units (RMUs), and thus do not capture variations in population trends, impacts of threats, or necessary conservation actions across individual populations. To address this issue, we developed a new assessment framework that allowed us to evaluate, compare and organize marine turtle RMUs according to status and threats criteria. Because conservation priorities can vary widely (i.e. from avoiding imminent extinction to maintaining long-term monitoring efforts) we developed a conservation priorities portfolio system using categories of paired risk and threats scores for all RMUs (n = 58). We performed these assessments and rankings globally, by species, by ocean basin, and by recognized geopolitical bodies to identify patterns in risk, threats, and data gaps at different scales. This process resulted in characterization of risk and threats to all marine turtle RMUs, including identification of the world\u27s 11 most endangered marine turtle RMUs based on highest risk and threats scores. This system also highlighted important gaps in available information that is crucial for accurate conservation assessments. Overall, this priority-setting framework can provide guidance for research and conservation priorities at multiple relevant scales, and should serve as a model for conservation status assessments and priority-setting for widespread, long-lived taxa

    Regional Management Units for Marine Turtles: A Novel Framework for Prioritizing Conservation and Research across Multiple Scales

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    Background: Resolving threats to widely distributed marine megafauna requires definition of the geographic distributions of both the threats as well as the population unit(s) of interest. In turn, because individual threats can operate on varying spatial scales, their impacts can affect different segments of a population of the same species. Therefore, integration of multiple tools and techniques - including site-based monitoring, genetic analyses, mark-recapture studies and telemetry - can facilitate robust definitions of population segments at multiple biological and spatial scales to address different management and research challenges. Methodology/Principal Findings: To address these issues for marine turtles, we collated all available studies on marine turtle biogeography, including nesting sites, population abundances and trends, population genetics, and satellite telemetry. We georeferenced this information to generate separate layers for nesting sites, genetic stocks, and core distributions of population segments of all marine turtle species. We then spatially integrated this information from fine-to coarse-spatial scales to develop nested envelope models, or Regional Management Units (RMUs), for marine turtles globally. Conclusions/Significance: The RMU framework is a solution to the challenge of how to organize marine turtles into units of protection above the level of nesting populations, but below the level of species, within regional entities that might be on independent evolutionary trajectories. Among many potential applications, RMUs provide a framework for identifying data gaps, assessing high diversity areas for multiple species and genetic stocks, and evaluating conservation status of marine turtles. Furthermore, RMUs allow for identification of geographic barriers to gene flow, and can provide valuable guidance to marine spatial planning initiatives that integrate spatial distributions of protected species and human activities. In addition, the RMU framework - including maps and supporting metadata - will be an iterative, user-driven tool made publicly available in an online application for comments, improvements, download and analysis

    Chandra Observations of the Crab-like Supernova Remnant G21.5-0.9

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    Chandra observations of the Crab-like supernova remnant G21.5-0.9 reveal a compact central core and spectral variations indicative of synchrotron burn-off of higher energy electrons in the inner nebula. The central core is slightly extended, perhaps indicating the presence of an inner wind-shock nebula surrounding the pulsar. No pulsations are observed from the central region, yielding an upper limit of ~40% for the pulsed fraction. A faint outer shell may be the first evidence of the expanding ejecta and blast wave formed in the initial explosion, indicating a composite nature for G21.5-0.9.Comment: 4 pages, 2 figures, formatted with emulateapj, submitted to ApJ

    Mojave desert tortoise (Gopherus agassizii) thermal ecology and reproductive success along a rainfall cline

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    Desert resource environments (e.g. microclimates, food) are tied to limited, highly localized rainfall regimes which generate microgeographic variation in the life histories of inhabitants. Typically, enhanced growth rates, reproduction and survivorship are observed in response to increased resource availability in a variety of desert plants and short‐lived animals. We examined the thermal ecology and reproduction of US federally threatened Mojave desert tortoises (Gopherus agassizii), long‐lived and large‐bodied ectotherms, at opposite ends of a 250‐m elevation‐related rainfall cline within Ivanpah Valley in the eastern Mojave Desert, California, USA. Biophysical operative environments in both the upper‐elevation, “Cima,” and the lower‐elevation, “Pumphouse,” plots corresponded with daily and seasonal patterns of incident solar radiation. Cima received 22% more rainfall and contained greater perennial vegetative cover, which conferred 5°C‐cooler daytime shaded temperatures. In a monitored average rainfall year, Cima tortoises had longer potential activity periods by up to several hours and greater ephemeral forage. Enhanced resource availability in Cima was associated with larger‐bodied females producing larger eggs, while still producing the same number of eggs as Pumphouse females. However, reproductive success was lower in Cima because 90% of eggs were depredated versus 11% in Pumphouse, indicating that predatory interactions produced counter‐gradient variation in reproductive success across the rainfall cline. Land‐use impacts on deserts (e.g. solar energy generation) are increasing rapidly, and conservation strategies designed to protect and recover threatened desert inhabitants, such as desert tortoises, should incorporate these strong ecosystem‐level responses to regional resource variation in assessments of habitat for prospective development and mitigation efforts.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111753/1/inz212132.pd

    High-density rhesus macaque oligonucleotide microarray design using early-stage rhesus genome sequence information and human genome annotations

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    BACKGROUND: Until recently, few genomic reagents specific for non-human primate research have been available. To address this need, we have constructed a macaque-specific high-density oligonucleotide microarray by using highly fragmented low-pass sequence contigs from the rhesus genome project together with the detailed sequence and exon structure of the human genome. Using this method, we designed oligonucleotide probes to over 17,000 distinct rhesus/human gene orthologs and increased by four-fold the number of available genes relative to our first-generation expressed sequence tag (EST)-derived array. RESULTS: We constructed a database containing 248,000 exon sequences from 23,000 human RefSeq genes and compared each human exon with its best matching sequence in the January 2005 version of the rhesus genome project list of 486,000 DNA contigs. Best matching rhesus exon sequences for each of the 23,000 human genes were then concatenated in the proper order and orientation to produce a rhesus "virtual transcriptome." Microarray probes were designed, one per gene, to the region closest to the 3' untranslated region (UTR) of each rhesus virtual transcript. Each probe was compared to a composite rhesus/human transcript database to test for cross-hybridization potential yielding a final probe set representing 18,296 rhesus/human gene orthologs, including transcript variants, and over 17,000 distinct genes. We hybridized mRNA from rhesus brain and spleen to both the EST- and genome-derived microarrays. Besides four-fold greater gene coverage, the genome-derived array also showed greater mean signal intensities for genes present on both arrays. Genome-derived probes showed 99.4% identity when compared to 4,767 rhesus GenBank sequence tag site (STS) sequences indicating that early stage low-pass versions of complex genomes are of sufficient quality to yield valuable functional genomic information when combined with finished genome information from a closely related species. CONCLUSION: The number of different genes represented on microarrays for unfinished genomes can be greatly increased by matching known gene transcript annotations from a closely related species with sequence data from the unfinished genome. Signal intensity on both EST- and genome-derived arrays was highly correlated with probe distance from the 3' UTR, information often missing from ESTs yet present in early-stage genome projects

    Persistent Leatherback Turtle Migrations Present Opportunities for Conservation

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    Effective transboundary conservation of highly migratory marine animals requires international management cooperation as well as clear scientific information about habitat use by these species. Populations of leatherback turtles (Dermochelys coriacea) in the eastern Pacific have declined by >90% during the past two decades, primarily due to unsustainable egg harvest and fisheries bycatch mortality. While research and conservation efforts on nesting beaches are ongoing, relatively little is known about this population of leatherbacks' oceanic habitat use and migration pathways. We present the largest multi-year (2004–2005, 2005–2006, and 2007) satellite tracking dataset (12,095 cumulative satellite tracking days) collected for leatherback turtles. Forty-six females were electronically tagged during three field seasons at Playa Grande, Costa Rica, the largest extant nesting colony in the eastern Pacific. After completing nesting, the turtles headed southward, traversing the dynamic equatorial currents with rapid, directed movements. In contrast to the highly varied dispersal patterns seen in many other sea turtle populations, leatherbacks from Playa Grande traveled within a persistent migration corridor from Costa Rica, past the equator, and into the South Pacific Gyre, a vast, low-energy, low-productivity region. We describe the predictable effects of ocean currents on a leatherback migration corridor and characterize long-distance movements by the turtles in the eastern South Pacific. These data from high seas habitats will also elucidate potential areas for mitigating fisheries bycatch interactions. These findings directly inform existing multinational conservation frameworks and provide immediate regions in the migration corridor where conservation can be implemented. We identify high seas locations for focusing future conservation efforts within the leatherback dispersal zone in the South Pacific Gyre

    Adapting the Marine Stewardship Council risk-based framework to estimate impacts on seabirds, marine mammals, marine turtles and sea snakes

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    Information available on impacts of fisheries on target or bycatch species varies greatly, requiring development of risk assessment tools to determine potentially unacceptable levels. Seabirds, marine mammals, marine turtles and sea snakes are particularly vulnerable given their extreme life histories, and data are often lacking on their populations or bycatch rates with which to quantify fisheries impacts. The Marine Stewardship Council (MSC) use a semi-quantitative Productivity Susceptibility Analysis (PSA) that is applicable to all species, target and non-target, to calculate risk of impact and to provide a score for relevant Performance Indicators for fisheries undertaking certification. The most recent MSC Fisheries Standard Review provided an opportunity to test the appropriateness of using this tool and whether it was sufficiently precautionary for seabirds, marine mammals and reptiles . The existing PSA was tested on a range of species and fisheries and reviewed in relation to literature on these species groups. New taxa-specific PSAs were produced and then reviewed by taxa-specific experts and other relevant stakeholders (e.g., assessors, fisheries managers, non-governmental conservation organizations). The conclusions of the Fishery Standard Review process were that the new taxa-specific PSAs were more appropriate than the existing PSA for assessing fisheries risk for seabirds, marine mammals and reptiles, and that, as intended, they resulted in precautionary outcomes. The taxa-specific PSAs provide useful tools for true data-deficient fisheries to assess relative risk of impact. Where some data are available, the MSC could consider developing or adapting other approaches to support robust and relevant risk assessments

    Updating requirements for Endangered, Threatened and Protected species MSC Fisheries Standard v3.0 to operationalise best practices

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    Bycatch in fisheries is a key threat to non-target marine species, particularly for those species that have life histories with low productivity or poor conservation status. In this paper, the requirements of the new Marine Stewardship Council (MSC) Fisheries Standard (hereafter “the Standard”) are summarised relevant to Endangered, Threatened and Protected (ETP) species. This covers both how species are designated as ETP, and how performance of management is assessed with respect to ETP species, when scoring fisheries against the Standard. The process used to select these requirements is described, including a review of the requirements for earlier versions of the Standard and the scoring of these requirements in assessment reports for a selection of fisheries that have achieved MSC certification. The review identified a lack of consistency in the implementation of scoring guidelines, which was in part due to a lack of clarity in the requirements of the Standard. The revised Standard has been designed to achieve more consistent implementation of the requirements with respect to management of impacts on ETP species, and to align the requirements more closely with global best practice. The requirements may be used as a template for fisheries managers seeking to prioritise bycatch species for improved management and setting more specific and measurable objectives in relation to population status and minimising mortalities

    Retrieving C and O Abundance of HR 8799 c by Combining High- and Low-Resolution Data

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    The formation and evolution pathway for the directly-imaged multi-planetary system HR 8799 remains mysterious. Accurate constraints on the chemical composition of the planetary atmosphere(s) are key to solving the mystery. We perform a detailed atmospheric retrieval on HR 8799~c to infer the chemical abundances and abundance ratios using a combination of photometric data along with low- and high-resolution spectroscopic data (R\sim20-35,000). We specifically retrieve [C/H], [O/H], and C/O and find them to be 0.550.39+0.36^{+0.36}_{-0.39}, 0.470.32+0.31^{+0.31}_{-0.32}, and 0.670.15+0.12^{+0.12}_{-0.15} at 68\% confidence. The super-stellar C and O abundances, yet a stellar C/O ratio, reveal a potential formation pathway for HR 8799~c. Planet c, and likely the other gas giant planets in the system, formed early on (likely within \sim1 Myr), followed by further atmospheric enrichment in C and O through the accretion of solids beyond the CO iceline. The enrichment either preceded or took place during the early phase of the inward migration to the planet current locations.Comment: 19 pages, 6 figures, 3 tables, accepted to AAS journal

    Global Conservation Priorities for Marine Turtles

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    Where conservation resources are limited and conservation targets are diverse, robust yet flexible priority-setting frameworks are vital. Priority-setting is especially important for geographically widespread species with distinct populations subject to multiple threats that operate on different spatial and temporal scales. Marine turtles are widely distributed and exhibit intra-specific variations in population sizes and trends, as well as reproduction and morphology. However, current global extinction risk assessment frameworks do not assess conservation status of spatially and biologically distinct marine turtle Regional Management Units (RMUs), and thus do not capture variations in population trends, impacts of threats, or necessary conservation actions across individual populations. To address this issue, we developed a new assessment framework that allowed us to evaluate, compare and organize marine turtle RMUs according to status and threats criteria. Because conservation priorities can vary widely (i.e. from avoiding imminent extinction to maintaining long-term monitoring efforts) we developed a “conservation priorities portfolio” system using categories of paired risk and threats scores for all RMUs (n = 58). We performed these assessments and rankings globally, by species, by ocean basin, and by recognized geopolitical bodies to identify patterns in risk, threats, and data gaps at different scales. This process resulted in characterization of risk and threats to all marine turtle RMUs, including identification of the world's 11 most endangered marine turtle RMUs based on highest risk and threats scores. This system also highlighted important gaps in available information that is crucial for accurate conservation assessments. Overall, this priority-setting framework can provide guidance for research and conservation priorities at multiple relevant scales, and should serve as a model for conservation status assessments and priority-setting for widespread, long-lived taxa
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