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931.
Richard G. Lathrop Jr. Scott M. Haag Daniel Merchant Michael J. Kennish Benjamin Fertig 《Journal of Coastal Conservation》2014,18(3):299-308
With the increasing appreciation that sea grass habitats are in global decline, there is a great need to be able to efficiently and effectively assess and characterize the status and trends of sea grass in our coastal ecosystems. This paper examines the utility of remotely sensed vs. in situ plot-based monitoring using the Barnegat Bay-Little Egg Harbor (BB-LEH), New Jersey, USA estuarine system as a case study. Eelgrass (Zostera marina) is the dominant species, while widgeon grass (Ruppia maritima) is also common in lower salinity regions of the BB-LEH. Aerial imagery collected during the months of July and August 2009 was interpreted and mapped using object based image analysis techniques, similar to techniques used in the 2003 mapping survey of this system. Boat-based in situ monitoring data were collected concurrently with the aerial photography to assist the image interpretation and for an independent accuracy assessment. We compared the remotely-sensed mapping of sea grass cover change (in 2003 vs. 2009) vs. in situ plot-based monitoring conducted from 2004 through 2009. Comparison of the remotely-sensed vs. the in situ plot-change analysis suggests that the two methodologies had broadly similarly results, with the percent area showing declines in sea grass cover greater than those that exhibited increases. In conclusion, the two studies provide corroborating evidence that sea grass has declined in percent cover in the BB-LEH system during the decade of the 2000’s. While remotely-sensed surveys provide synoptic information for a “big picture” view on sea grass distribution, site specific in situ sampling is required to determine other aspects of sea grass status, e.g. above vs. below-ground biomass, blade length, shoot density, epiphytic loading, etc. Either method alone gives an incomplete picture. As demonstrated in this study, to fully characterize the spatial extent, health, and density of sea grass meadows across the entire estuary, combining remote sensing surveys concomitantly with comprehensive in situ assessment provides the most robust approach. 相似文献
932.
Scott T. McDonough David S. Woodward Michael J. Doherty Scott A. Underhill 《补救:环境净化治理成本、技术与工艺杂志》2013,23(2):121-125
The New York State Department of Environmental Conservation (NYSDEC) Division of Environmental Remediation (DER) issued a program policy focused on the overall sustainability of hazardous waste site cleanups on August 11, 2010. This DER‐31/Green Remediation program policy (DER‐31) was issued in accordance with 6 New York Codes, Rules and Regulations (NYCRR) Part 375 Environmental Remediation Programs. DER‐31 represents one of the first government‐issued green and sustainable remediation (GSR) policies in the United States. Consistent with other DER policies, DER‐31's provisions are broadly considered to be an expectation/requirement. GSR experts from within AECOM's Remediation Services (RS) Practice Area developed and implemented a GSR program designed to comply with DER‐31 provisions and have now broadly incorporated GSR into our New York remediation projects. Lessons learned from this experience in New York have influenced AECOM's global GSR program and implementation procedures and prompted the development of a new GSR tool (GSRxTM) for identifying and assessing GSR best management practices (BMPs), which has also been employed globally. © 2013 Wiley Periodicals, Inc. 相似文献
933.
934.
Matthew D. Einheuser A. Pouyan Nejadhashemi Lizhu Wang Scott P. Sowa Sean A. Woznicki 《Environmental management》2013,51(6):1147-1163
Land use change and other human disturbances have significant impacts on physicochemical and biological conditions of stream systems. Meanwhile, linking these disturbances with hydrology and water quality conditions is challenged due to the lack of high-resolution datasets and the selection of modeling techniques that can adequately deal with the complex and nonlinear relationships of natural systems. This study addresses the above concerns by employing a watershed model to obtain stream flow and water quality data and fill a critical gap in data collection. The data were then used to estimate fish index of biological integrity (IBI) within the Saginaw Bay basin in Michigan. Three methods were used in connecting hydrology and water quality variables to fish measures including stepwise linear regression, partial least squares regression, and fuzzy logic. The IBI predictive model developed using fuzzy logic showed the best performance with the R 2 = 0.48. The variables that identified as most correlated to IBI were average annual flow, average annual organic phosphorus, average seasonal nitrite, average seasonal nitrate, and stream gradient. Next, the predictions were extended to pre-settlement (mid-1800s) land use and climate conditions. Results showed overall significantly higher IBI scores under the pre-settlement land use scenario for the entire watershed. However, at the fish sampling locations, there was no significant difference in IBI. Results also showed that including historical climate data have strong influences on stream flow and water quality measures that interactively affect stream health; therefore, should be considered in developing baseline ecological conditions. 相似文献
935.
Jongmin Yoon T. Scott Sillett Scott A. Morrison Cameron K. Ghalambor 《Behavioral ecology and sociobiology》2013,67(10):1691-1697
Males of some oscine passerines learn and share songs of neighboring males. This process can lead to the formation of song pattern neighborhoods or microhabitat song dialects. The degree to which song sharing occurs between populations and the spatial scale over which neighboring males share songs, however, can vary widely, and interpopulation comparisons have suggested that song sharing is more common in residents than in migrants. Here, we examine two populations of the orange-crowned warbler (Oreothlypis celata) to quantify patterns of song sharing at the northern (long-distance migrant) and southern (short-distance migrant) edges of the breeding distribution and to test if return rate, territory fidelity, and breeding dispersal explain the patterns found in the two populations. The southern population (O. celata sordida breeding on Santa Catalina Island, California; 33°N) had a higher annual return rate to their territories and exhibited higher song sharing in neighborhoods than their counterparts (O. celata celata breeding in Fairbanks, Alaska; 64°N). Year-to-year patterns of territory fidelity and breeding dispersal distances were similar between populations. Our results suggest that if migratory distance generally covaries with the proportion of returning males, this could explain different levels of song sharing between the short- and long-distance migrants. 相似文献
936.
Evaluating the Effects of Three Forms of Marine Reserve on Northern Abalone Populations in British Columbia, Canada 总被引:2,自引:0,他引:2
S. Scott Wallace 《Conservation biology》1999,13(4):882-887
Abstract: Marine reserves have been suggested as tools for assisting the management of fisheries by protecting vulnerable marine species from overexploitation. Although there is a theoretical basis for believing that marine reserves may serve as management tools, there are few marine reserves in the world in which to test their effectiveness. My research evaluated three forms of marine reserve on the south coast of Vancouver Island, British Columbia, Canada. I used northern abalone ( Haliotis kamtschatkana ), a severely depleted shellfish in this region, as an indicator of the effectiveness of the reserves. Abalone populations in eight sites receiving different degrees of spatial protection were counted and measured in situ during the spring of 1996 and 1997. In all sites with enforced harvest closures, populations of abalone were greater, and one site with nearly 40 years of protection had on average much larger (older) abalone. Reproductive output, as a function of abundance and size, was also greater in the enforced reserve areas. Larval dispersal from reserves, and hence the benefit to exploited areas, was not formally surveyed. Nevertheless, the results of my study, combined with knowledge of present abalone populations, life history, and regional hydrodynamics, suggest that establishment of reserves is justified in the absence of perfect knowledge of larval dispersal. 相似文献
937.
938.
Application of a scenario-based modeling system to evaluate the air quality impacts of future growth
Jülide Kahyaoğlu-Koračin Scott D. Bassett David A. Mouat Alan W. Gertler 《Atmospheric environment (Oxford, England : 1994)》2009,43(5):1021-1028
The structure and design of future urban development can have significant adverse effects on air pollutant emissions as well as other environmental factors. When considering the future impact of growth on mobile source emissions, we generally model the increase in vehicle kilometers traveled (VKT) as a function of population growth. However, diverse and poorly planned urban development (i.e., urban sprawl) can force higher rates of motor vehicle use and in return increase levels of pollutant emissions than alternative land-use scenarios. The objective of this study is to develop and implement an air quality assessment tool that takes into account the influence of alternative growth and development scenarios on air quality.The use of scenario-based techniques in land use planning has been around since the late 1940s and been tested in many different applications to aid in decision-making. In this study, we introduce the development of an advanced interactive scenario-based land use and atmospheric chemistry modeling system coupled with a GIS (Geographical Information System) framework. The modeling system is designed to be modular and includes land use/land cover information, transportation, meteorological, emissions, and photochemical modeling components. The methods and modularity of the developed system allow its application to both broad areas and applications.To investigate the impact of possible land use change and urbanization, we evaluated a set of alternative future patterns of land use developed for a study area in Southwest California. Four land use and two population variants (increases of 500k and 1M) were considered. Overall, a Regional Low-Density Future was seen to have the highest pollutant emissions, largest increase in VKT, and the greatest impact on air quality. On the other hand, a Three-Centers Future appeared to be the most beneficial alternative future land-use scenario in terms of air quality. For all cases, the increase in population was the main factor leading to the change on predicted pollutant levels. 相似文献
939.
Scott Chambers Wlodek Zahorowski Kiyoshi Matsumoto Mitsuo Uematsu 《Atmospheric environment (Oxford, England : 1994)》2009,43(2):271-279
Three years of hourly atmospheric radon measurements at Sado Island (Japan) are discussed and compared with corresponding measurements at Gosan (South Korea), and Hok Tsui (China). In conjunction with back trajectory analysis, Sado radon data are used to characterise the seasonal variability in fetch regions of air masses subject to extremes of terrestrial influence. In winter, fetch regions of air masses that have experienced the greatest terrestrial influence covered southern Siberia; in summer, the terrestrial fetch was dominated by Japan; throughout the remaining months the terrestrial fetch encompassed the Korean Peninsula and far eastern China. Summer radon data are then used to estimate the radon flux from central Honshu (23.5 mBq m?2 s?1), which varied regionally between 10.6 and 47.9 mBq m?2 s?1. The Sado radon record reported here completes a 4-site, multi-year dataset of hourly radon concentrations across East Asia and the central Pacific (spanning 16° of latitude), which constitutes a unique evaluation tool for transport and mixing schemes of atmospheric and chemical transport models. 相似文献
940.
Fowler SW 《Journal of environmental radioactivity》2011,102(5):448-461
The distribution and behaviour of the natural-series alpha-emitter polonium-210 in the marine environment has been under study for many years primarily due to its enhanced bioaccumulation, its strong affinity for binding with certain internal tissues, and its importance as a contributor to the natural radiation dose received by marine biota as well as humans consuming seafoods. Results from studies spanning nearly 5 decades show that 210Po concentrations in organisms vary widely among the different phylogenic groups as well as between the different tissues of a given species. Such variation results in 210Po concentration factors ranging from approximately 103 to over 106 depending upon the organism or tissue considered. 210Po/210Pb ratios in marine species are generally greater than unity and tend to increase up the food chain indicating that 210Po is preferentially taken up by organisms compared to its progenitor 210Pb. The effective transfer of 210Po up the food chain is primarily due to the high degree of assimilation of the radionuclide from ingested food and its subsequent strong retention in the organisms. In some cases this mechanism may lead to an apparent biomagnification of 210Po at the higher trophic level. Various pelagic species release 210Po and 210Pb packaged in organic biodetrital particles that sink and remove these radionuclides from the upper water column, a biogeochemical process which, coupled with scavenging rates of this radionuclide pair, is being examined as a possible proxy for estimating downward organic carbon fluxes in the sea. Data related to preferential bioaccumulation in various organisms, their tissues, resultant radiation doses to these species, and the processes by which 210Po is transferred and recycled through the food web are discussed. In addition, the main gaps in our present knowledge and proposed areas for future studies on the biogeochemical behaviour of 210Po and its use as a tracer of oceanographic processes are highlighted in this review. 相似文献