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Results for “Chesapeake Bay Journal”

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At least 37 records · Page 2Linked to original sources
USGS1993

Overwinter distribution of northern pintail populations in North America

Northern pintails ( Anas acuta ) exist as a single circumpolar breeding population but display weak fidelity to given breeding sites. If fidelity to wintering areas is strong, management on wintering grounds may allow local winter populations to increase. Thus, I delineated reference areas for wintering areas based on recovery data for pintails banded during the winter (Dec-Feb) in the United States. Fidelity to these reference areas varied with the strongest fidelity observed for pintails banded in areas along coastal areas or near large bodies of water such as western Washington-northwestern Oregon, central California, northwestern Utah, the Texas-Louisiana Gulf Coast, and the Greater Chesapeake Bay Region. My analysis suggests that pintails occurred in distinct wintering populations and that wintering ground affiliations to certain areas appear to be more stable population units than breeding ground affiliations. Consequently, winter banding programs may be useful in monitoring survival of specific wintering populations of concern.

North America↗
USGS2003

Determination of alkylphenol and alkylphenolethoxylates in biota by liquid chromatography with detection by tandem mass spectrometry and fluorescence spectroscopy

A quantitative method for the simultaneous determination of octylphenol, nonylphenol and the corresponding ethoxylates (1 to 5) in biota is presented. Extraction methods were developed for egg and fish matrices based on accelerated solvent extraction followed by a solid-phase extraction cleanup, using octadecylsilica or aminopropyl cartridges. Identification and quantitation were accomplished by liquid chromatography-electrospray tandem mass spectrometry (LC-MS-MS) and compared to the traditional liquid chromatography with fluorescence spectroscopy detection. LC-MS-MS provides high sensitivity and specificity required for these complex matrices and an accurate quantitation with the use of 13C-labeled internal standards. Quantitation limits by LC-MS-MS ranged from 4 to 12 ng/g in eggs, and from 6 to 22 ng/g in fish samples. These methods were successfully applied to osprey eggs from the Chesapeake Bay and fish from the Great Lakes area. Total levels found in osprey egg samples were up to 18 ng/g wet mass and as high as 8.2 ug/g wet mass in the fish samples.

Journal of Chromatography A↗
USGS2014

An approach for mapping large-area impervious surfaces: Synergistic use of Landsat-7 ETM+ and high spatial resolution imagery

A wide range of urban ecosystem studies, including urban hydrology, urban climate, land use planning, and resource management, require current and accurate geospatial data of urban impervious surfaces. We developed an approach to quantify urban impervious surfaces as a continuous variable by using multisensor and multisource datasets. Subpixel percent impervious surfaces at 30-m resolution were mapped using a regression tree model. The utility, practicality, and affordability of the proposed method for large-area imperviousness mapping were tested over three spatial scales (Sioux Falls, South Dakota, Richmond, Virginia, and the Chesapeake Bay areas of the United States). Average error of predicted versus actual percent impervious surface ranged from 8.8 to 11.4%, with correlation coefficients from 0.82 to 0.91. The approach is being implemented to map impervious surfaces for the entire United States as one of the major components of the circa 2000 national land cover database.

Canadian Journal of Remote Sensing↗
USGS1985

An aerial photographic census of Chesapeake Bay and North Carolina canvasbacks

We used conventional 35-mm photography to conduct an aerial photographic census of canvasbacks ( Aythya valisineria ) throughout Chesapeake Bay (tidal Maryland and Virginia) and coastal North Carolina, 26-30 January 1981. Flock size and sex ratio characteristics were determined from examination of color transparencies of 165 canvasback flocks totaling over 95,000 birds. A sex ratio of 2.91 males/female was determined from 68,769 birds, 80% of the birds in 150 flocks. Sex ratio for the Atlantic Flyway was projected as 2.90 males/female. We recorded the greatest number of canvasbacks and the widest range of flock size in Maryland waters; the fewest canvasbacks and the smallest average flock size in Virginia; and the fewest but on average the largest flocks of canvasbacks in North Carolina. Sex ratio varied latitudinally in the flyway with a tendency for males to occupy more northern and females more southern latitudes in winter. Sex ratio (males/female) was highest in Maryland (3.98), slightly lower in Virginia (3.71), and lowest in North Carolina (1.70). Locally, sex ratio varied with flock size. In Chesapeake Bay, small flocks (<100 birds) had lower sex ratio (P < 0.05) than medium (100-1,000) or large (>1,000) flocks. By providing large- sample sex ratio information, as well as exact counts of birds, we conclude that low-level 35-mm aerial photography is the most efficient and accurate means of determining canvasback population status in eastern coastal habitats.

Maryland, North Carolina, Virginia↗
USGS2010

Islands at bay: Rising seas, eroding islands, and waterbird habitat loss in Chesapeake Bay (USA)

Like many resources in the Chesapeake Bay region of the U.S., many waterbird nesting populations have suffered over the past three to four decades. In this study, historic information for the entire Bay and recent results from the Tangier Sound region were evaluated to illustrate patterns of island erosion and habitat loss for 19 breeding species of waterbirds. Aerial imagery and field data collected in the nesting season were the primary sources of data. From 1993/1994 to 2007/2008, a group of 15 islands in Tangier Sound, Virginia were reduced by 21% in area, as most of their small dunes and associated vegetation and forest cover were lost to increased washovers. Concurrently, nesting American black ducks ( Anas rubripes) declined by 66% , wading birds (herons-egrets) by 51%, gulls by 72%, common terns (Sterna hirundo) by 96% and black skimmers ( Rynchops niger ) by about 70% in this complex. The declines noted at the larger Bay-wide scale suggest that this study area maybe symptomatic of a systemic limitation of nesting habitat for these species. The island losses noted in the Chesapeake have also been noted in other Atlantic U.S. coastal states. Stabilization and/or restoration of at least some of the rapidly eroding islands at key coastal areas are critical to help sustain waterbird communities.

Virginia↗
USGS2018

Estimates of tidal-marsh bird densities using Bayesian networks

Conserving tidal-marsh bird communities requires strategies to address continuing pressures from human development to the effects of increasing rates of sea-level rise. Knowing tidal-marsh bird distributions and population sizes are important for developing these strategies. In the Northeast United States, where estimates of sea-level rise are 3 times higher than the global average, 5 bird species are tidal-marsh specialists: clapper rail (Rallus crepitans), willet (Tringa semipalmata), Nelson's sparrow (Ammospiza nelsoni), saltmarsh sparrow (A. caudacuta), and seaside sparrow (A. maritima). We used a regional marsh bird survey to develop Bayesian network models to identify factors that influence patch-scale species density and to estimate regional population sizes. We modeled species density as a function of habitat covariates at the patch, local, landscape, and regional spatial scales. Densities were most sensitive to patch location and dimension, patch geomorphic setting, indices of human development, and changes in mean sea level. We estimated 110,000 clapper rails (95% CI = 61,000–159,000), 111,000 willets (95% CI = 70,000–152,000), 7,000 Nelson's sparrows (95% CI = 4,000–10,000), 60,000 saltmarsh sparrows (95% CI = 40,000–80,000), and 234,000 seaside sparrows (95% CI = 112,000–356,000) from the United States–Canada border to, and including, the mouth of the Chesapeake Bay, Virginia, USA. Our abundance estimates can be used to identify priority conservation areas at multiple geographic scales and our models help identify key habitat and landscape components for tidal-marsh restoration and management to benefit tidal-marsh birds and can be modified for other species.

Maine, New Hampshire, Massachusetts, Rhode Island,↗
USGS2006

The effects of the Chesapeake Bay impact on calcareous nannofossil assemblages: patterns from the Watkins School core, Newport News, Virginia (USA)

The goal of this study was to assess the effect that the Late Eocene Chesapeake Bay bolide impact had on local patterns of calcareous nannofossil species composition, richness and preservation. Although calcareous nannofossil assemblages have been described from a handful of coreholes drilled within the impact structure, this is the first study to examine the calcareous nannofossils from the Watkins School core , which was recovered along the outer rim of the crater. A detailed stratigraphic assessment of the calcareous nannofossil assemblages across the synimpact-postimpact boundary was performed to determine whether the impact produced any local extinction. The results obtained suggest that, despite its size, the Chesapeake Bay impact did not significantly affect the local calcareous nannoplankton community. Little or no change was documented across the synimpact-postimpact boundary in calcareous nannofossil species composition, richness or preservation quality. These findings do not support the existence of a calcareous nannofossil 'dead zone' in this particular core; however, the presence of impact-fractured calcareous nannofossils does attest to the tremendous pressures generated by the impact.

Virginia↗
USGS1981

Environmental metal residues in tissues of canvasbacks

Reduction and deterioration of habitat and high nest predation have contributed to the decline of the continental populations of canvasbacks (Aythya valisineria) (Trauger 1974). Environmental metal contaminants also may adversely affect reproduction and survival of waterfowl (Heinz 1974, 1976a,b, 1979; Finley and Stendell 1978). White et al. (1979) ex- amined canvasbacks from Chesapeake Bay in 1975 and 1976 and found low levels of lead, cadmium, and mercury in certain tissues. Low levels of mercury in canvasbacks have also been reported from Wisconsin (Kleinert and Degurse 1972) and Saskatchewan (Vermeer and Armstrong 1972). Stendell et al. (1977) found mercury residues in 6 of 34 canvasback eggs collected in 1972 and 1973. The objective of my study was to ascertain levels of mercury, lead, cadmium, and nickel in canvasbacks from the upper Mississippi River

Journal of Wildlife Management↗
USGS2025

Highly pathogenic avian influenza virus H5N1 in double-crested cormorants (Nannopterum auritum) of the Chesapeake Bay, USA

Double-crested Cormorants ( Nannopterum auritum ) have historically exhibited low levels of infection and antibodies to avian influenza virus (AIV). The recent global expansion of clade 2.3.4.4b A/goose/Guangdong/1/1996 highly pathogenic (HP) avian influenza virus H5N1 (HPAI H5N1) has resulted in large-scale mortalities across diverse waterbird taxa including cormorants. We sampled 32 and 29 Double-crested Cormorants breeding in the Chesapeake Bay, US, during the summers of 2023 and 2024, respectively, to assess HPAI H5N1 infection and AIV antibodies. Although no mortality was observed in the area, one bird sampled in 2023 was infected with HPAI H5N1. Additionally, 21/31 individuals in 2023 and 10/25 individuals in 2024 for which sera were collected had AIV antibodies. Based on additional testing using hemagglutination inhibition, virus neutralization, and an enzyme-linked lectin assay, 94 and 100% (2023 and 2024, respectively) of the seropositive birds tested positive for antibodies to both H5 and N1, suggesting previous infection with HPAI H5N1. These results are consistent with survival and limited clinical effects related to HPAI H5N1 infections. Furthermore, these results suggest that population immunity to HPAI H5N1 within the Chesapeake Bay might reduce future infections and potential population impacts should HP H5N1 remain on the landscape, though immunity may be waning across time. Because results are based on a single population, additional testing for both infection and antibodies as well as continued monitoring could enhance understanding of antibody persistence.

Maryland, Virginia↗
USGS1991

Environmental contaminants in bald eagle eggs

Bald Eagle eggs (1968-84) were analyzed for organochlorine pesticides, PCBs and mercury. DDE declined in WI, ME and the Chesapeake Bay. DDE was most closely related to shell thickness and reproduction at sampled breeding areas. Sixteen ppm DDE (wet weight) was associated with 15% shell thinning. Reproduction was normal when eggs at sampled breeding areas contained <3.6 ppm DDE; success was nearly halved between 3.6 and 6.3 ppm and halved again when concentrations exceeded 6.3 ppm. Other contaminants were associated with poor reproduction and eggshell thinning; however, their impact appeared secondary to that of DDE.

Journal of Raptor Research↗
USGS2000

Capturing American black ducks in tidal waters

We modified conventional, funnel-entrance dabbling duck bait traps to increase captures for banding of American Black Ducks (Anas rubripes) in tidal saltmarsh habitats of Smith Island, Maryland, one of the few remaining strongholds for breeding Black Ducks in the Chesapeake Bay. Traps and trapping techniques were adapted to tidal creeks and refined to improve capture rate, reduce mortality, and minimize interference by gulls. Best results were achieved by synchronizing trapping with predawn, low-tide foraging patterns of Black Ducks. Trap entrances were critical to retaining ducks, and use of loafing platforms reduced overall mortality to 3% of captures per year. We captured 3071 Black Ducks during the 14-year period, 1984-199

Journal of Field Ornithology↗
USGS1997

Avian cholera in ospreys: first occurrence and possible mode of transmission

In 1994, six Ospreys (Pandion haliaetus) were recovered during the later stages of an epizootic of avian cholera (Pasteurella multocida) in diving ducks and seabirds on Chesapeake Bay in Maryland and Virginia. Pasteurella multocida was isolated from four Ospreys submitted for bacterial examination. This is believed to be the first report of avian cholera in Ospreys. The same isolate, serotype 3,4, was isolated from the Ospreys, diving ducks,and seabirds collected during the epizootic. Possible modes of transmission of avian cholera in Ospreys were either the ingestion of sick waterfowl or use of infected carcasses or bones as nest material.

Maryland, Virginia↗
USGS1976

Blood values of the canvasback duck by age, sex and season

Blood samples were obtained from canvasback ducklings from Manitoba and Saskatchewan and from immature and adult canvasbacks on the Mississippi River near LaCrosse, Wisconsin and the Chesapeake Bay. These samples were used to determine baseline data on red cell counts, hematocrit, total protein, glucose, cholesterol, hemaglobin and distribution of plasma proteins. Calculations were also made to determine mean corpuscular volume, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration. The major differences noted were between ducklings and adults. The former having higher total protein and lower hematocrit, glucose and cholesterol values. These hematologic values were collected in order to provide baseline information on apparently healthy canvasbacks, thereby providing disease investigators with a standard of comparison.

Canada, United States↗
USGS2024

Identifying the forage base and critical forage taxa for Chesapeake waterbirds

To effectively maximize the conservation value of management plans intended to capture ecosystem-wide health, it is essential to obtain an understanding of emergent patterns in dietary dynamics spanning many species. Chesapeake Bay, USA, is a critical ecosystem used annually by a diverse assortment of waterbird species, including several of conservation concern. However, the ecosystem is threatened by many ecological pressures driven largely by the dense human population of the surrounding region. These issues necessitate proactive monitoring and management efforts to track the health of ecosystems like the Chesapeake Bay. Such monitoring efforts of population dynamics require adequate data on the connections between trophic levels to understand how changes to the forage base might influence higher trophic levels, such as these diverse avian predators. However, we have historically lacked standardized quantitative data drawing these connections at the community level, as well as the relative importance of these taxa in the diet of such predators. We collated existing quantitative data on avian dietary composition to construct a database on the diets of 58 waterbird species that make use of the Chesapeake Bay. From this database, we quantified the relative importance of forage taxa to the diet of each waterbird species. Such data can enable managers to develop a comprehensive suite of forage taxa indicators whose abundance and distributions can be monitored as a proxy for ecosystem health. It is our goal that this database be harnessed as a tool to enable conservation practitioners to prioritize indicator taxa for monitoring purposes, contributing towards conservation plans that best address the health of the ecosystem at large.

Delaware, Maryland, Virginia↗
USGS2014

Catinaster virginianus sp. nov.: A new species of Catinaster from the middle Miocene Mid-Atlantic Coastal Plain

High-resolution analysis of sediments from four coreholes associated with the Chesapeake Bay impact crater has resulted in the identification of a new species, Catinaster virginianus. This species is similar to Catinaster coalitus coalitus, but differs in having a proximal stem. The first occurrence of C. virginianus is in Zone NN5, and is older than any previously identified Catinaster . This species has been identified previously as Catinaster sp. from the Gulf of Mexico and the Carpathian Foredeep and suggests both a global distribution and synchronous stratigraphic range. Morphologic similarities with Discoaster variabilis may suggest a taxonomic relationship to the D. variabilis lineage.

Chesapeake Bay↗
USGS2023

Societal benefits of floodplains in the Chesapeake Bay and Delaware River watersheds: Sediment, nutrient, and flood regulation ecosystem services

Floodplains provide critical ecosystem services to people by regulating floodwaters and retaining sediments and nutrients. Geospatial analyses, field data collection, and modeling were integrated to quantify a portfolio of services that floodplains provide to downstream communities within the Chesapeake Bay and Delaware River watersheds. The portfolio of services included floodplain sediment and nutrient retention and flood regulation. Sediment and nutrient retention were quantified and valued for all non-tidal wadable streams in the Chesapeake Bay and Delaware River watersheds. Predicted nitrogen fluxes from measurements of streambanks and floodplain geomorphic changes were summarized at various scales (river basin, state, and county) and valued using a benefits transfer approach. Floodplain flood regulation services were assessed through a pilot study focused on the Schuylkill River watershed in the Delaware River watershed. Geospatial analysis and published flood frequency estimates were used to assess baseline and counterfactual (i.e., floodplain storage removed) scenarios. Flood regulation was valued using the Federal Emergency Management Agency's Hazus model to compare differences in structural damage to private residences under baseline and counterfactual scenarios. The estimated value of floodplain sediment and nutrient retention was \$223 million United States dollars (USD) per year in the Chesapeake Bay watershed and \$38 million USD per year in the Delaware River watershed. Sediment and nutrient retention benefits were offset by a streambank erosion cost of \$123 million and \$14 million USD annually in the Chesapeake and Delaware watersheds, respectively. In the Schuylkill River watershed floodplain flood regulation was valued at \$860,000 USD per year, with an additional \$7.2 million USD annually provided through floodplain sediment and nutrient retention. Together this portfolio of floodplain ecosystem services indicates that floodplains provide substantial benefits to people by trapping nutrients and storing floodwaters.

Chesapeake Bay and Delaware River watersheds↗
USGS1992

Implanting radio transmitters in wintering canvasbacks

To conduct telemetry studies of wintering canvasbacks ( Aythya valisineria ) on Chesapeake Bay [Maryland, USA], we needed to devise a suitable method of radio transmitter attachment. We describe as aseptic, intraabdominal surgical technique, using the inhalation anesthetic isoflurane, to implant 20-g radio transmitters in free-ranging canvasbacks. We evaluated the technique over 3 winters (1987-89), when an annual average of 83 female canvasbacks received implant surgery during a 9-day period in mid-December. Of 253 ducks, 248 (98%) were implanted successfully, and 200 (80.65) completed the 70-day study until early March. No mortality or abnormal behavior from surgery was identified post-release.

Maryland, Virginia↗