Description

Numbers of bald eagles Haliaeetus leucocephalus nesting along the lower Columbia River have doubled in the last six years, yet fiveyear running productivity averages are well below statewide values for eagles nesting in other areas of Oregon and Washington. While productivity of eagles along the Columbia River is low, nesting success in other areas of the two states is close to the goals established to delist the species from the Federal Endangered Species list. Previous contaminant studies conducted from 1985 to 1987 along the river found poor productivity associated with elevated DDE dichlorodiphenyldichloroethane and total polychlorinated biphenyls PCBs in eagle eggs. In addition, 2,3,7,8tetrachlorodibenzopdioxin TCDD and 2,3,7,8tetrachlorodibenzofuran TCDF concentrations were found in five eggs collected in 1987 and 1991. From 199495, fresh bald eagle eggs were collected from nests in 19 of 43 occupied territories along the river. Eggshell thickness was determined on all eggs, and the contents were analyzed for organochlorine pesticides, total PCBs, polychlorinated dibenzopdioxins PCDDs, polychlorinated dibenzofurans PCDFs, and planar PCBs nonortho and monoortho substituted congeners. Halogenated dioxinlike compounds in eggs were also evaluated based on a H4IIE rat hepatoma bioassay. Productivity and egg contaminant results from l 994 to 1995 were compared to a previous study to evaluate changes over time. Recent increases in productivity averages were due to new pairs nesting along the river, yet productivity at 23 older breeding areas remained low and was not different P0.713 between the two study periods. Eggshells averaged 11 percent thinner than shells measured prior to the use of the pesticide DDT dichlorodiphenyltrichloroethane, and thickness of eggs from older breeding territories had not improved P0.404 between the two study periods. Decreases in p,pDDE P0.022 and total PCBs P 0.0004 in eggs from older breeding areas occurred between the two study periods, but concentrations were still above values associated with poor productivity. TCDD toxic equivalents TEQs exceeded estimated noeffect values for bald eagles during both studies. Bald eagle productivity over a fiveyear time period encompassing egg collection was not correlated to individual organochlorine compounds. Some dioxins, furans, planar PCBs, and TEQ values were correlated to nest location as river mile, with highest concentrations occurring at downriver breeding territories near the mouth. Although total productivity has increased due to the success of new nesting pairs moving into the region, results indicate that organochlorine contaminants continue to impact the breeding success of lower Columbia River eagles. The greatest impact of appears to occur at older breeding territories, which were located predominantly in the lower estuary below river mile 60. Eagles nesting toward the mouth of the river may be at greater risk of exposure to some dioxinlike compounds, and the reproductive success of some new pairs nesting in this area could be impacted in the future.

General Information

• This data is described at

  http://catalog.data.gov/dataset/changes-in-productivity-and-environmental-contaminants-in-bald-eagles-nesting-along-the-lo Do you think this data is incorrect? Let us know

• This data is published by

  US Fish and Wildlife Service, Department of the Interior Do you think this data is incorrect? Let us know

Legal Information

• The rights statement is at

  http://catalog.data.gov/dataset/changes-in-productivity-and-environmental-contaminants-in-bald-eagles-nesting-along-the-lo Do you think this data is incorrect? Let us know

• Outside the US, this data is available under

  Creative Commons CCZero Do you think this data is incorrect? Let us know

• There are

  yes, and the rights are all held by the same person or organisation Do you think this data is incorrect? Let us know

• The content is available under

  Creative Commons CCZero Do you think this data is incorrect? Let us know

• The rights statement includes data about

  its data licence Do you think this data is incorrect? Let us know

• This data contains

  no data about individuals Do you think this data is incorrect? Let us know

Practical Information

• The data appears in this collection

  http://catalog.data.gov/organization/fws-gov Do you think this data is incorrect? Let us know

• The accuracy or relevance of this data will

  go out of date but it is timestamped Do you think this data is incorrect? Let us know

• The data is

  backed up offsite Do you think this data is incorrect? Let us know

Technical Information

• This data is published at

  http://ecos.fws.gov/ServCatFiles/reference/holding/21540?accessType=DOWNLOAD Do you think this data is incorrect? Let us know

• The format of this data is

  a standard open format Do you think this data is incorrect? Let us know

Social Information

• The documentation includes machine-readable data for

  title Do you think this data is incorrect? Let us know

• The documentation includes machine-readable data for

  description Do you think this data is incorrect? Let us know

• The documentation includes machine-readable data for

  identifier Do you think this data is incorrect? Let us know

• The documentation includes machine-readable data for

  landing page Do you think this data is incorrect? Let us know

• The documentation includes machine-readable data for

  publisher Do you think this data is incorrect? Let us know

• The documentation includes machine-readable data for

  keyword(s) or tag(s) Do you think this data is incorrect? Let us know

• The documentation includes machine-readable data for

  distribution(s) Do you think this data is incorrect? Let us know

• The documentation includes machine-readable data for

  release date Do you think this data is incorrect? Let us know

• The documentation includes machine-readable data for

  modification date Do you think this data is incorrect? Let us know

• The documentation includes machine-readable data for

  temporal coverage Do you think this data is incorrect? Let us know

• The documentation about each distribution includes machine-readable data for

  release date Do you think this data is incorrect? Let us know

• The documentation about each distribution includes machine-readable data for

  a URL to access the data Do you think this data is incorrect? Let us know

• The documentation about each distribution includes machine-readable data for

  a URL to download the dataset Do you think this data is incorrect? Let us know

• The documentation about each distribution includes machine-readable data for

  type of download media Do you think this data is incorrect? Let us know

• Find out how to contact someone about this data at

  http://catalog.data.gov/dataset/changes-in-productivity-and-environmental-contaminants-in-bald-eagles-nesting-along-the-lo Do you think this data is incorrect? Let us know

• Find out how to suggest improvements to publication at

  http://www.data.gov/issue/?media_url=http://catalog.data.gov/dataset/changes-in-productivity-and-environmental-contaminants-in-bald-eagles-nesting-along-the-lo Do you think this data is incorrect? Let us know