Monitoring Contaminants in the Arctic and
Subarctic Using Banked Seabird Eggs
More than 95% of the seabirds breeding in the continental United States nest at colonies in the Bering and Chukchi seas and Gulf of Alaska. In 1999, the U.S. Fish and Wildlife Service Alaska Maritime National Wildlife Refuge (USFWS-AMNWR), the U.S. Geological Survey Biological Resources Division (USGS-BRD), and NIST implemented the Seabird Tissue Archival and Monitoring Project (STAMP) to monitor contaminants in Alaska’s marine environments.
The project was designed as an ongoing long-term effort to track geographic and temporal trends in environmental quality by collecting Alaskan seabird eggs using standardized protocols, processing and banking the contents under conditions that ensure chemical stability during long-term (decadal) storage, and analyzing subsamples of the stored material to determine baseline levels of persistent bioaccumulative contaminants (e.g., chlorinated pesticides, polychlorinated biphenyls [PCBs], brominated flame retardants [polybrominated diphenyl ethers—PBDEs], butyltin compounds, and mercury). The seabird egg collection is maintained in NIST’s Marine Environmental Specimen Bank at the Hollings Marine Laboratory.
Seabirds are an important group of upper trophic-level marine organisms with potential for accumulating lipophilic contaminants. Analyses of seabird tissues, particularly eggs, have played important roles in temporal and spatial environmental monitoring of persistent organic pollutants (POPs—e.g., PCBs, chlorinated pesticides) and mercury in Canada and Europe. Through real-time analysis, specimen banking, and future retrospective analysis, the project will provide a means to monitor both legacy environmental contaminants and chemicals of emerging environmental concern and provides the capability to verify analytical results by accessing banked samples and reanalyzing them using more sensitive and accurate methods in the future.
Since 1999, STAMP has collected and banked eggs from five species of seabirds (common and thick-billed murre, glaucous and glaucous-winged gull, and black-legged kittiwake) with colonies distributed throughout the major marine regions of Alaska: Chukchi Sea and Bering Sea representing the Arctic and Gulf of Alaska representing the subarctic. Analytical work has concentrated on the two murre and two gull species. The murres are deep divers that feed on fish and invertebrates and the contents of their eggs integrate contaminant levels in the marine system. Gulls are more characteristic of the coastal environments and feed at various levels in the food web. Incorporation of gulls into the Project was due to their importance in Alaska Native subsistence diets (although murre eggs are also used for subsistence) and the request by the Bureau of Indian Affairs that gulls be considered for the project.
Through funding support from the North Pacific Research Board, new information on chlorinated pesticides, polychlorinated biphenyls (PCBs), brominated flame retardants, mercury, and organotin compounds in Alaska’s marine regions was produced by seabird egg analyses at NIST laboratories at the Hollings Marine Laboratory.
Results, suggest that eggs of murres are excellent for temporal and geographical monitoring contaminants in the marine ecosystem. Analysis of murre eggs collected in 2002-2005 confirmed earlier indications (from analysis of eggs collected in 1999–2002) of the presence of consistent geographic contaminant patterns. Persistent organic pollutant (POP) and mercury levels were generally higher in eggs from the Gulf of Alaska than those from the Bering and Chukchi seas. Also, almost 100% of the total mercury content of the eggs was found to be methylmercury. Temporal trends in the data covering the period 1999 – 2005 suggest that some POPs (e.g., PCBs, DDT, HCBs) are declining in the eggs. This does not appear to be the case for mercury.
Recent analytical results from STAMP resulted in additional support from NPRB to investigate what appear to be significantly higher levels of mercury in murre eggs from Norton Sound as compared to results from other colonies in the Bering Sea. The project is using more intensive collections of eggs from murres and gulls throughout the region to determine if this pattern is consistent and if food web characteristics or differences in mercury sources and cycling might be involved. Previous analysis of mercury stable isotopes in a subset of eggs showed that distinct isotope patterns exist over broad geographic regions. The project is now focusing this approach to the Norton Sound region by investigating the use of mercury isotopes as a proxy for sources and biogeochemical cycling, coupled with C and N stable isotopes to examine the effects of food webs on this determination.
- Temporal and geographic trends in the level of contaminants in the major marine regions of Alaska are being established through the analysis of seabird egg specimens banked at the Marine Environmental Specimen Bank.
- Banked seabird egg specimens are being used in a study to use mercury isotopes coupled with carbon and nitrogen stable isotopes to determine sources and cycling of mercury in the environment and the effects of food webs on this determination.
- STAMP is internationally recognized as a contributor to the Arctic Monitoring and Assessment Programme and in 2008 was designated as a component of the international AMAP/CAFF Coordinated Monitoring Effort.