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Berlin, MD, United States

Schupp C.A.,Assateague Island National Seashore | Winn N.T.,Assateague Island National Seashore | Pearl T.L.,Assateague Island National Seashore | Kumer J.P.,Assateague Island National Seashore | And 2 more authors.
Estuarine, Coastal and Shelf Science | Year: 2013

On Assateague Island, an undeveloped barrier island along Maryland and Virginia, a foredune was constructed to protect the island from the erosion and breaching threat caused by permanent jetties built to maintain Ocean City Inlet. Scientists and engineers integrated expertise in vegetation, wildlife, geomorphology, and coastal engineering in order to design a habitat restoration project that would be evaluated in terms of coastal processes rather than static features. Development of specific restoration targets, thresholds for intervention, and criteria to evaluate long-term project success were based on biological and geomorphological data and coastal engineering models. A detailed long-term monitoring plan was established to measure project sustainability. The foredune unexpectedly acted as near-total barrier to both overwash and wind, and the dynamic ecosystem underwent undesirable habitat changes including conversion of early-succession beach habitat to herbaceous and shrub communities, diminishing availability of foraging habitat and thereby reducing productivity of the Federally-listed Threatened Charadrius melodus (piping plover). To address these impacts, multiple notches were cut through the constructed foredune. The metric for initial geomorphological success-restoration of at least one overwash event per year across the constructed foredune, if occurring elsewhere on the island-was reached. New overwash fans increased island stability by increasing interior island elevation. At every notch, areas of sparse vegetation increased and the new foraging habitat was utilized by breeding pairs during the 2010 breeding season. However, the metric for long-term biological success-an increase to 37% sparsely vegetated habitat on the North End and an increase in piping plover productivity to 1.25 chicks fledged per breeding pair-has not yet been met. By 2010 there was an overall productivity of 1.2 chicks fledged per breeding pair and a 1.7% decrease in sparsely vegetated habitat. Ideally, overwash restoration will sustain the availability of foraging habitat, but future foredune modifications may be necessary to maintain or increase overwash processes and piping plover habitat in the project area. © 2012. Source

Eggert L.S.,Smithsonian Institution | Eggert L.S.,University of Missouri | Powell D.M.,Wildlife Conservation Society | Ballou J.D.,Smithsonian Institution | And 6 more authors.
Journal of Wildlife Management | Year: 2010

Recently, a number of papers have addressed the use of pedigrees in the study of wild populations, highlighting the value of pedigrees in conservation management. We used pedigrees to study the horses (Equus caballus) of Assateague Island National Seashore, Maryland, USA, one of a small number of free-ranging animal populations that have been the subject of long-term studies. This population grew from 28 in 1968 to 175 in 2001, causing negative impacts on the island ecosystem. To minimize these effects, an immunocontraception program was instituted, and horse numbers are slowly decreasing. However, there is concern that this program may negatively affect the genetic health of the herd. We found that although mitochondrial DNA diversity is low, nuclear diversity is comparable to that of established breeds. Using genetic data, we verified and amended maternal pedigrees that had been primarily based on behavioral data and inferred paternity using genetic data along with National Park Service records of the historic ranges of males. The resulting pedigrees enabled us to examine demography, founder contributions, rates of inbreeding and loss of diversity over recent generations, as well as the level of kinship among horses. We then evaluated the strategy of removing individuals (using nonlethal means) with the highest mean kinship values. Although the removal strategy increased the retained diversity of founders and decreased average kinship between individuals, it disproportionately impacted sizes of the youngest age classes. Our results suggest that a combined strategy of controlled breeding and immunocontraception would be more effective than removing individuals with high mean kinships in preserving the long-term health and viability of the herd. © 2010 The Wildlife Society. Source

Carruthers T.J.B.,University of Cambridge | Beckert K.,University of Cambridge | Schupp C.A.,Assateague Island National Seashore | Saxby T.,University of Cambridge | And 7 more authors.
Estuarine, Coastal and Shelf Science | Year: 2013

To achieve desired environmental outcomes, environmental condition and trends need to be rigorously measured and communicated to resource managers, scientists, and a broader general audience. However, there is often a disconnect between responsive ecosystem monitoring and decision making for strategic long-term management. This project demonstrates how historical monitoring data can be synthesized and used for future planning and decision making, thereby closing the management feedback cycle. This study linked disparate datasets, collected for a variety of purposes and across multiple temporal and spatial scales, in order to assess and quantify current habitat conditions. The results inform integrated resource management decision-making at Assateague Island National Seashore (Maryland and Virginia, USA) by using ecological reference conditions to identify monitoring needs, areas of high vulnerability, and areas with potential for improved management. The approach also provides a framework that can be applied in the future to assess the effectiveness of these management decisions on the condition of island habitats, and is a replicable demonstration of incorporating diverse monitoring datasets into an adaptive management cycle. © 2012. Source

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