19 research outputs found

    Accounting for Unintended Consequences of Resource Policy: Connecting Research that Addresses Displacement of Environmental Impacts

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    Natural resource policies enacted to protect environmental integrity play an important role in promoting sustainability. However, when resources are shared ecologically, economically, or through a common, global interest, policies implemented to protect resource sustainability in one domain can displace, and in some cases magnify, environmental degradation to other domains. Although such displacement has been recognized as a fundamental challenge to environmental and conservation policy within some resource sectors, there has been little cross‐disciplinary and cross‐sectoral integration to address the problem. This suggests that siloed knowledge may be impeding widespread recognition of the ubiquity of displacement and the need for mitigation. Here, we connect research across multiple disciplines to promote a broader discussion and recognition of the processes and pathways that can lead to displaced impacts that countermand or undermine resource policy and outline a number of approaches that can mitigate displacement

    A Method for Estimating Marine Habitat Values Based on Fish Guilds, with Comparisons between Sites in the Southern California Bight

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    Habitat valuation is an essential tool for tracking changes in habitat quality and in adjudicating environmental mitigation. All current methods for estimating habitat values of coastal marine sites rely heavily on the opinion of experts or on data variables that can readily be manipulated to influence the outcome. As a result, unbiased, quantitative comparisons between the values of different marine habitats are generally unavailable. We report here on a robust, objective technique for the valuation of marine habitats that makes use of data that are commonly gathered in surveys of marine fish populations: density, fidelity, and mean size. To insure comparability across habitats, these variables are assessed for guilds of fishes, rather than for single species. The product of the three guild-based parameters is transformed to its square root and then summed across all guilds in the habitat, yielding a single measure of habitat value for each site surveyed. To demonstrate the usefulness of this approach, we have analyzed data from existing surveys of 13 marine sites in the Southern California Bight, encompassing 98 fish species from 23 guilds. For seven of the sites, it was possible to develop estimates of the confidence interval of the habitat valuation, using a resampling technique. Variance estimates from resampling in one habitat mirrored those derived from analysis of annual variation. The resultant ranking of habitat types was: kelp beds \u3e shallow artificial reefs \u3e wetlands \u3e protected shallow waters (soft bottom) \u3e shallow open coastal sand (depth \u3c30 m) \u3e soft bottom habitat on the continental shelf (30 m \u3c depth \u3c200 m) \u3e soft bottom habitat on the continental slope (depth \u3e200 m). Although our data sets were restricted to Southern California, similar data could be obtained from any reasonably well-studied marine environment. The guild-based valuation technique may, therefore, be broadly applicable to the analysis of other marine ecosystems

    Satellite Network Performance Measurements Using Simulated Multi-User Internet Traffic

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    As a number of diverse satellite systems (both Low Earth Orbit and Geostationary systems) are being designed and deployed, it becomes increasingly important to be able to test these systems under realistic traffic loads. While software simulations can provide valuable input into the system design process, it is crucial that the physical system be tested so that actual network devices can be employed and tuned. These tests need to utilize traffic patterns that closely mirror the expected user load, without the need to actually deploy an end-user network for the test. In this paper, we present trafgen. trafgen uses statistical information about the characteristics of sampled network traffic to emulate the same type of traffic over the test network. This paper compares sampled terrestrial network traffic with emulated satellite network traffic over the NASA ACTS satellite

    Abstract

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    As a number of diverse satellite systems (both Low Earth Orbit and Geostationary systems) are being designed and deployed, it becomes increasingly important to be able to test these systems under realistic traffic loads. While software simulations can provide valuable input into the system design process, it is crucial that the physical system be tested so that actual network devices can be employed and tuned. These tests need to utilize traffic patterns that closely mirror the expected user load, without the need to actually deploy an end-user network for the test. In this paper, we present trafgen. trafgen uses statistical information about the characteristics of sampled network traffic to emulate the same type of traffic over the test network. This paper compares sampled terrestrial network traffic with emulated satellite network traffic over the NASA ACTS satellite
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