Changes in the regulation and use of some organic chemicals have caused environmental concentrations to stabilize or decline during the past 35 years coincident with a rebound in the osprey (Pandion haliaetus) population of the Chesapeake Bay.
The U.S. Environmental Protection Agency (EPA) classifies more than 70 percent of Chesapeake Bay tidal waters as impaired by toxic contaminants. To track these contaminants and their effects on bay ospreys, water, fish, osprey eggs, and blood samples from osprey chicks were sampled along Chesapeake Bay tributaries in Pennsylvania, Maryland, and Virginia, including several sites the EPAconsiders "Regions of Concern." These findings were published in three manuscripts, with the article published in the journal Integrated Environmental Assessment and Management, being named the Best Student Paper published in a Society of Environmental Toxicology and Chemistry journal for 2015.
Results from samples collected during the summer nesting season from 2011 through 2013 were compared to results from a 2000–1 study that showed levels of polychlorinated biphenyls (PCBs) had not changed significantly, not only in the last 10 years, but during the past 35 years. Residues of the pesticide dichlorodiphenyltrichloroethane (DDT) and the related compound, dichlorodiphenyl-dichloroethylene (p,p'-DDE), had decreased by approximately 80 percent during the same period of time to concentrations below the levels that caused the eggshell thinning responsible for osprey and bald eagle population declines in the 20th century. Although polybrominated diphenyl ethers (PBDE) flame retardants (also potentially toxic to wildlife) had declined slightly, samples from nests located near wastewater treatment plants (WWTPs) indicate that hotspots remain. Although Bay osprey populations have rebounded, one marker of genetic damage in osprey chick blood samples from some Regions of Concern and WWTPs was elevated compared to samples taken at a relatively uncontaminated reference site, which indicates the ongoing effects of these contaminants.
Currently used (2016) pharmaceuticals were also evaluated in this study to assess their bioaccumulation potential. The bioaccumulation potential was calculated by determining the concentration of these contaminants in prey fish and water near nesting sites to predict uptake in fish and ospreys. To complement the exposure model, water, fish, and osprey nestling blood were analyzed for 23 active pharmaceuticals or their metabolites and an artificial sweetener. Of the 18 analytes detected in water, 8 were found in fish blood but only 1 in osprey nestling blood (antihypertensive diltiazem). Although all of the detected compounds were well below the human therapeutic concentrations, their effects at the observed concentrations (or of their metabolites) are unknown.
Overall, the osprey population is thriving in the Chesapeake Bay. Their population has increased from 1,450 pairs in the 1970s to 3,500 during the mid-1990s. Recent observations in several tributaries indicate that the Chesapeake Bay osprey population may be approaching 10,000 pairs, which is more than 6 times greater than their nadir during the DDT-use era.
This study was funded by the U.S. Geological Survey (USGS) Chesapeake Bay Program, USGS Ecosystem Mission Area's Environmental Health Program (Contaminant Biology Program and Toxic Substances Hydrology), and Texas Sea Grant Program.
Below are other science projects associated with this project.
Long-term Studies Examine Contaminant Exposure and Reproduction of Ospreys Nesting in Two Large United States Estuaries
Endocrine Disrupting Compounds in the Chesapeake Bay Watershed Science Team
Pharmaceuticals and the Water-Fish-Osprey Food Web
Ospreys used as sentinel for pollution
See below for related publications.
Chesapeake Bay fish–osprey (Pandion haliaetus) food chain: Evaluation of contaminant exposure and genetic damage
Exposure and food web transfer of pharmaceuticals in ospreys (Pandion haliaetus): Predictive model and empirical data
Decadal re-evaluation of contaminant exposure and productivity of ospreys (Pandion haliaetus) nesting in Chesapeake Bay Regions of Concern
Contaminant exposure and reproductive success of Ospreys (Pandion haliaetus) nesting in Chesapeake Bay regions of concern
- Overview
Changes in the regulation and use of some organic chemicals have caused environmental concentrations to stabilize or decline during the past 35 years coincident with a rebound in the osprey (Pandion haliaetus) population of the Chesapeake Bay.
Game camera image of an osprey taken on Poplar Island, Maryland. Game cameras were used to identify species of fish fed to osprey nestlings. Photo Credit: Game camera placed by Rebecca S. Lazarus, USGS. The U.S. Environmental Protection Agency (EPA) classifies more than 70 percent of Chesapeake Bay tidal waters as impaired by toxic contaminants. To track these contaminants and their effects on bay ospreys, water, fish, osprey eggs, and blood samples from osprey chicks were sampled along Chesapeake Bay tributaries in Pennsylvania, Maryland, and Virginia, including several sites the EPAconsiders "Regions of Concern." These findings were published in three manuscripts, with the article published in the journal Integrated Environmental Assessment and Management, being named the Best Student Paper published in a Society of Environmental Toxicology and Chemistry journal for 2015.
Results from samples collected during the summer nesting season from 2011 through 2013 were compared to results from a 2000–1 study that showed levels of polychlorinated biphenyls (PCBs) had not changed significantly, not only in the last 10 years, but during the past 35 years. Residues of the pesticide dichlorodiphenyltrichloroethane (DDT) and the related compound, dichlorodiphenyl-dichloroethylene (p,p'-DDE), had decreased by approximately 80 percent during the same period of time to concentrations below the levels that caused the eggshell thinning responsible for osprey and bald eagle population declines in the 20th century. Although polybrominated diphenyl ethers (PBDE) flame retardants (also potentially toxic to wildlife) had declined slightly, samples from nests located near wastewater treatment plants (WWTPs) indicate that hotspots remain. Although Bay osprey populations have rebounded, one marker of genetic damage in osprey chick blood samples from some Regions of Concern and WWTPs was elevated compared to samples taken at a relatively uncontaminated reference site, which indicates the ongoing effects of these contaminants.
U.S. Geological Survey scientists monitoring an osprey nest on Back River, Maryland. Photo Credit: Peter C. McGowan, U.S. Fish and Wildlife Service. Currently used (2016) pharmaceuticals were also evaluated in this study to assess their bioaccumulation potential. The bioaccumulation potential was calculated by determining the concentration of these contaminants in prey fish and water near nesting sites to predict uptake in fish and ospreys. To complement the exposure model, water, fish, and osprey nestling blood were analyzed for 23 active pharmaceuticals or their metabolites and an artificial sweetener. Of the 18 analytes detected in water, 8 were found in fish blood but only 1 in osprey nestling blood (antihypertensive diltiazem). Although all of the detected compounds were well below the human therapeutic concentrations, their effects at the observed concentrations (or of their metabolites) are unknown.
Overall, the osprey population is thriving in the Chesapeake Bay. Their population has increased from 1,450 pairs in the 1970s to 3,500 during the mid-1990s. Recent observations in several tributaries indicate that the Chesapeake Bay osprey population may be approaching 10,000 pairs, which is more than 6 times greater than their nadir during the DDT-use era.
This study was funded by the U.S. Geological Survey (USGS) Chesapeake Bay Program, USGS Ecosystem Mission Area's Environmental Health Program (Contaminant Biology Program and Toxic Substances Hydrology), and Texas Sea Grant Program.
- Science
Below are other science projects associated with this project.
Long-term Studies Examine Contaminant Exposure and Reproduction of Ospreys Nesting in Two Large United States Estuaries
In a series of studies from 2010 to 2018, U.S. Geological Survey (USGS) scientists detected low levels of legacy contaminants and pharmaceuticals in osprey (Pandion haliaetus) and their food chain within the Chesapeake and Delaware River estuaries. Osprey reproductive success increased during the same period and was determined to be adequate to sustain a stable population in both estuaries.Endocrine Disrupting Compounds in the Chesapeake Bay Watershed Science Team
The Chesapeake Bay is the largest estuary in the United States and provides critical resources to fish, wildlife and people. For more than a decade, recreational fish species have been plagued with skin lesions and intersex conditions (the presence of male and female sex characteristics in the same fish) that biologists attributed to exposures to endocrine disrupting chemicals (EDCs)...Pharmaceuticals and the Water-Fish-Osprey Food Web
Pharmaceuticals have found their way into the environment. The impact on wildlife is unknown. Ospreys occupy the top of the food web, often nest in highly industrialized or urban areas, and eat only fish, making them an ideal sentinel for monitoring localized contaminants.Ospreys used as sentinel for pollution
Monitoring the buildup of chemical compounds in ospreys helps scientists track toxics in our waterways. - Publications
See below for related publications.
Chesapeake Bay fish–osprey (Pandion haliaetus) food chain: Evaluation of contaminant exposure and genetic damage
From 2011 to 2013, a large-scale ecotoxicological study was conducted in several Chesapeake Bay (USA) tributaries (Susquehanna River and flats, the Back, Baltimore Harbor/Patapsco Rivers, Anacostia/ middle Potomac, Elizabeth and James Rivers) and Poplar Island as a mid-Bay reference site. Osprey (Pandion haliaetus) diet and the transfer of contaminants from fish to osprey eggs were evaluated. TheAuthorsRebecca S. Lazarus, Barnett A. Rattner, Peter C. McGowan, Robert C. Hale, Natalie K. Karouna-Reiner, Richard A. Erickson, Mary Ann OttingerExposure and food web transfer of pharmaceuticals in ospreys (Pandion haliaetus): Predictive model and empirical data
The osprey (Pandion haliaetus) is a well-known sentinel of environmental contamination, yet no studies have traced pharmaceuticals through the water–fish–osprey food web. A screening-level exposure assessment was used to evaluate the bioaccumulation potential of 113 pharmaceuticals and metabolites, and an artificial sweetener in this food web. Hypothetical concentrations in water reflecting “wasteAuthorsRebecca S. Lazarus, Barnett A. Rattner, Bowen Du, Peter C. McGowan, Vicki S. Blazer, Mary Ann OttingerDecadal re-evaluation of contaminant exposure and productivity of ospreys (Pandion haliaetus) nesting in Chesapeake Bay Regions of Concern
The last large-scale ecotoxicological study of ospreys (Pandion haliaetus) in Chesapeake Bay was conducted in 2000-2001 and focused on U.S. EPA-designated Regions of Concern (ROCs; Baltimore Harbor/Patapsco, Anacostia/middle Potomac, and Elizabeth Rivers). In 2011-2012, ROCs were re-evaluated to determine spatial and temporal trends in productivity and contaminants. Concentrations of p,p'-DDE wereAuthorsRebecca S. Lazarus, Barnett A. Rattner, Peter C. McGowan, Robert C. Hale, Sandra L. Schultz, Natalie K. Karouna-Renier, Mary Ann OttingerContaminant exposure and reproductive success of Ospreys (Pandion haliaetus) nesting in Chesapeake Bay regions of concern
The Chesapeake Bay osprey population has more than doubled in size since restrictions were placed on the production and use of DDT and other toxic organochlorine contaminants in the 1970s. Ospreys are now nesting in the most highly polluted portions of the Bay. In 2000 and 2001, contaminant exposure and reproduction were monitored in ospreys nesting in regions of concern, including Baltimore HarboAuthorsBarnett A. Rattner, P. C. McGowan, N. H. Golden, J. S. Hatfield, P. C. Toschik, R.F. Lukei, R. C. Hale, I. Schmitz-Afonso, C.P. Rice