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EVALUATION OF MARINE
CONTAMINANTS AND DEBRIS 
IN SEADUCKS


The health of seaducks is poorly understood and little is known about contaminant levels in these marine animals. Seaducks can be the primary animals impacted by ocean pollution and are susceptible to ingestion or contamination by floating material. Therefore, it is important to study the baseline health status of these animals and to understand the likely impacts that result from marine debris. There are ongoing efforts to study baseline contaminants in marine mammals through the NOAA marine mammal program, and so this project will focus on seaducks.

The USGS collects seaducks for analyses of ingested food items. This project will examine other tissues for levels of contaminants. Evaluation of the quality and quantity of contaminants affecting seaduck has not been documented.

Clear documentation of contaminant loads in this population of Atlantic seaducks has not been established. Gross external examinations will include evaluation of obvious anomalies, overall body condition, weight, and age. Internal gross examinations will include evaluation of gross in situ organ appearance and sex determination. Gizzard contents will be evaluated for identification of foreign materials as part of another ongoing project looking at food habits. Contaminants to be examined include heavy metals (tin, mercury, selenium, cadmium) and PCBs (Arochlor 1254). Tributyltin is found in anti-fouling paint used on ship hulls to prevent creatures like barnacles from attaching, and accumulates in marine invertebrates which are ingested by marine animals throughout the food chain. Methylmercury is the most toxic form of mercury and the most bioaccumulative. 

It is also the most dominant form of mercury in fish. Burning of fossil fuels with atmospheric deposition accounts for greater than 50% of environmental mercury. Toxic effects can be found in kidneys and reproductive organs and become endocrine disruptors. Selenium is an essential, but potentially toxic element with a narrow margin of tolerance in animals. It is also known to co-accumulate with mercury and may actually enhance its toxic effects. Selenium in irrigation water runoffs contribute to developmental problems and death of fish and bird embryos. 

Cadmium has increased in the environment primarily due to metal smelting and burning of fossil fuels. It accumulates in sediments and is a source of contamination of benthic organisms often ingested by birds. Toxic signs in birds include kidney and reproductive organ failure in addition to contributing to biochemical stressors resulting in immunosuppression . Potential tissues to be collected for contaminants include liver, kidney, muscle or brain. Tissues from the above project will be utilized for contaminant analyses and results will be made available to the federal agencies collaborating to supply the carcasses for the project.

Tissue collection will be conducted from approximately 100 seaducks along the Atlantic seaboard. Analyses will be conducted at the Toxicology Laboratory at the Virginia-Maryland Regional College of Veterinary Medicine, Blacksburg, VA.

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