Most migratory shorebird species are declining, some are endangered, and some may be vulnerable to contaminants on long distance travel between wintering grounds and high latitude breeding grounds. We examined whether shorebirds accumulated trace elements at the Delaware Bay (New Jersey) stopover by testing the null hypothesis that there was no difference in the levels of arsenic, cadmium, chromium, lead, mercury, and selenium in blood of three species of shorebirds collected early in their stopover compared to levels in blood collected about two weeks later near the end of the stopover, before departing for breeding grounds. There were significantly higher levels of all metals and metalloids in the blood of ruddy turnstone (Arenaria interpres) later in May than earlier.
View Article and Find Full Text PDFUnderstanding the relationship between heavy metal and selenium levels in biota and their foods is important, but often difficult to determine because animals eat a variety of organisms. Yet such information is critical to managing species populations, ecological integrity, and risk to receptors (including humans) from consumption of certain prey. We examine levels of cadmium, lead, mercury, and selenium in biota from Delaware Bay (New Jersey, USA) to begin construction of a "springtime" food web that focuses on shorebirds.
View Article and Find Full Text PDFIdentifying animals as sentinels for humans and other animal species is an excellent method for understanding exposure to environmental contamination at different times and places. Shorebirds are useful sentinels because they have a world-wide distribution, eat a range of prey, and are eaten by a range of other species, including humans. We collected blood from semipalmated sandpipers (Calidris pusilla) wintering in northern (Suriname N = 71) and northeastern (Brazil N = 61) South America to examine levels of heavy metals and metalloids (arsenic, selenium), and compare them to blood levels in sandpipers at a heavily used stopover site in New Jersey (N = 30; Delaware Bay, NJ).
View Article and Find Full Text PDFIt is essential to understand contaminant exposure and to compare levels of contaminants in organisms at different ages to determine if there is bioaccumulation, and to compare levels encountered in different geographical areas. In this paper, we report levels of mercury, lead, cadmium, cobalt, arsenic and selenium in the blood of semipalmated sandpipers () wintering in Suriname as a function of age, and compare them to blood levels in northbound migrants at a stopover in Delaware Bay, New Jersey. We found (1) young birds had higher levels of cadmium, cobalt, and lead than adults (after second year birds); (2) there were no age-related differences for arsenic, mercury and selenium; (3) only four of the possible 16 inter-metal correlations were significant, at the 0.
View Article and Find Full Text PDFUnderstanding the relationship between metal level in predators and their prey is an important issue, and is usually difficult to determine because animals eat a variety of organisms. However, shorebirds that stop over during spring migration along Delaware Bay (New Jersey) stay for only 2-3 weeks, and eat mainly horseshoe crab () eggs. In this paper, we examine the relationship between metal levels in horseshoe crab eggs, and blood and feather levels of metals in red knot (; = 30), sanderling (; = 20) and semipalmated sandpiper (; = 38) from Delaware Bay.
View Article and Find Full Text PDFArch Environ Contam Toxicol
May 2017
We investigated levels of arsenic mercury, lead, cadmium, and chromium in Red Knot (Calidris canutus), Semipalmated Sandpipers (Calidris pusilla), and Sanderling (Calidris alba) migrating through Delaware Bay, New Jersey to determine if contaminant levels are likely to be causing negative effects on the populations of these shorebirds, to compare among species, and to explore differences among individuals collected early and late during their migration stopover. We analyzed blood and feathers, both nonlethal ways of exploring contaminants in birds. Blood contaminant analysis provides a direct measure of recent dietary exposure, whereas feathers reflect body burden at the time of feather molt.
View Article and Find Full Text PDFStakeholder contributions to conservation projects often occur during the problem formulation stage, yet the role of stakeholders throughout the process is seldom considered. We examine the diversity of state and federal agencies, conservation organizations, other non-governmental organizations, environmental justice communities, consultants, industry, and the general public in the conservation of red knot (Calidris canutus rufa) and black skimmer (Rynchops niger) in New Jersey. We suggest that (1) governmental agencies provide the legal, regulatory, and management framework, but it is often the universities, conservation organizations, consultants, and the public that conduct the research and perform activities that lead to increased research and conservation efforts; (2) departments within agencies may have conflicting mandates, making it difficult to resolve differences in actions; (3) there is often conflict among and within state agencies and conservation organizations about roles and priorities; and (4) the role of the public is critical to ongoing research and conservation efforts.
View Article and Find Full Text PDFUnderstanding temporal changes in contaminant levels in coastal environments requires comparing levels of contaminants from the same species from different time periods, particularly if species are declining. Several species of shorebirds migrating through Delaware Bay have declined from the 1980s to the present. To evaluate some contaminants as cause for the declines, we examine levels of mercury, lead, cadmium, arsenic, chromium and selenium in feathers of red knot (, = 46 individuals), semipalmated sandpiper (, = 70) and sanderling (, = 32) migrating through Delaware Bay, New Jersey, USA, from 1991 to 1992 ( = 40), 1995 ( = 28), and 2011-2012 ( = 80) to determine if levels have changed.
View Article and Find Full Text PDFEnviron Monit Assess
October 2014
The health of horseshoe crab (Limulus polyphemus) eggs is important not only to maintain horseshoe crab populations, but because they are a resource for higher trophic levels, such as fish and shorebirds. We examined the concentrations of arsenic, cadmium, chromium, lead, manganese, mercury, and selenium in the eggs of horseshoe crabs from Delaware Bay (between New Jersey and Delaware, USA) in 1993, 1994, 1995, 1999, 2000, and 2012 to determine if there were significant temporal changes and if levels appear to pose a health risk to the crabs themselves, or to predators that consume them. All metal levels declined in horseshoe crab eggs between 1994 and 2012, although the declines were much less consistent for lead and chromium than that for mercury and cadmium.
View Article and Find Full Text PDFThere is an abundance of field data on levels of metals for feathers in a variety of birds, but relatively few data for tissues, especially for migrant species from one location. In this paper we examine the levels of arsenic, cadmium, chromium, lead, manganese, mercury and selenium in muscle, liver, brain, fat and breast feathers from migrant semipalmated sandpipers (Calidris pusilla) collected from Delaware Bay, New Jersey. Our primary objectives were to (1) examine variation as a function of tissue, (2) determine the relationship of metal levels among tissues, and (3) determine the selenium:mercury molar ratio in different tissues since selenium is thought to protect against mercury toxicity.
View Article and Find Full Text PDFThis study investigated the impacts of urban wetlands and their adjacent residential environments on the transmission dynamics of West Nile virus (WNV) within the state of New Jersey (USA). A working hypothesis was that urban wetlands decrease the local prevalence of WNV through the dilution effect from increased bird diversity, and through relative reductions in the numbers of competent avian host and mosquito species commonly associated with WNV. Surveys of mosquito and bird communities were undertaken at six urban wetlands and their adjacent residential environments over two seasons (2009, 2010).
View Article and Find Full Text PDFThe New Jersey Meadowlands are located within the heavily urbanized New York/New Jersey Harbor Estuary and have been subject to contamination due to effluent and runoff from industry, traffic, and homes along the Hackensack River and nearby waterways. These extensive wetlands, though heavily impacted by development and pollution, support a wide array of bird and other wildlife species. Persistent contaminants may pose threats to birds in these habitats, affecting reproduction, egg hatchability, nestling survival, and neurobehavioral development.
View Article and Find Full Text PDFArch Environ Contam Toxicol
October 2008
Scientists interested in contamination normally deal only with pollution itself, not with people's perceptions of pollution or the relationship between pollution and land use. The overall objective of this article was to examine the relationship between people's perceptions of pollution and their views on future land use. People were interviewed at an Earth Day Festival near the Department of Energy's Brookhaven National Laboratory (BNL) on Long Island, New York.
View Article and Find Full Text PDFThe New Jersey Meadowlands is an important natural area, a diverse mosaic of wetland habitats positioned within the heavily urbanized NY City Metropolitan area and the NY/NJ Harbor. Persistent contaminants may pose threats to wildlife inhabiting these habitats, affecting reproduction, egg hatchability, nestling survivorship, and neurobehavioral development. Metals of concern in the Meadowlands include arsenic, cadmium, chromium, lead, and mercury.
View Article and Find Full Text PDFThere is considerable concern for the health of spawning populations of horseshoe crabs (Limulus polyphemus) along the east coast of North America because of an increase in the harvest, an apparent decrease in population levels, and the dependence of migrating shorebirds on a superabundant supply of horseshoe crab eggs during their migratory stopover on Delaware Bay. In addition to overfishing, population declines could be caused or recovery slowed, by pollution. In this paper, we examine the levels of metals (arsenic, cadmium, chromium, lead, manganese, mercury, and selenium) in the eggs, leg muscle, and apodeme of 100 horseshoe crabs collected at nine sites from Maine to Florida.
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