Diagnostic Tools and Technologies for Assessing Effects of Contaminants and Pathogens in Marine Wildlife
Project Status: This project began in January 2010 and was completed in December 2013
Chemical and pathogen pollutants transported into coastal waters from land-based sources pose health hazards for marine wildlife, particularly marine mammals that feed at the top of the coastal food chain. Unfortunately, impacts may go undetected until a catastrophic incident such as an unusual mortality event occurs. We are developing improved diagnostic tools and technologies to provide early warning of adverse health effects in marine wildlife resulting from exposure to pollutants.
Why We Care
As the human population expands in coastal areas and distribution of pathogens and hosts shift with changing climate, the risk for emerging hazards in the marine environment increases. While there is concern that marine wildlife may be negatively affected, there is also concern for human health. Marine wildlife may act directly as vectors or reservoirs for chemicals and pathogens to expose humans that consume contaminated seafood or recreate in coastal waters. Marine animals may also serve indirectly as sentinels to provide early warning of emerging threats in the coastal environment.
What We Did
We are working in collaboration with our partners to develop rapid-screening diagnostic tools and molecular methods including:
Genomic tools—such as microarrays and RNA sequence analysis—to identify biomarkers of chemical and pathogen exposure;
Assays and field equipment to provide rapid detection of infectious agents—both terrestrial and aquatic in nature—present in clinical samples collected from marine mammals; and
Assays to detect and quantify levels of multiple endocrine hormones in remotely biopsied marine mammal tissues.
Our partners include the Medical University of South Carolina, University of California–Davis, the National Marine Fisheries Service’s Office of Protected Resources and its National Marine Mammal Stranding Network, and NOAA’s Southwest Fisheries Science Center.
What We Found
We found that in some areas of the U.S. coast, legacy contaminants such as polychlorinated biphenyls (PCBs) that entered the environment decades ago have persisted and migrated over large distances. We have detected these contaminants in marine mammals and other marine biota, even in relatively undeveloped coastal marshes and protected areas. We have found that PCBs and other chemical contaminants are impacting the health of coastal dolphins, specifically affecting their endocrine systems and thus decreasing their survival and their ability to reproduce.
These diagnostic tools are at varying stages of development. We are using microarrays for testing dolphin and sea lion blood samples and enhancing these microarrays with RNA sequence analysis for expanded applications. We are using assays developed for pathogen detection in marine mammal clinical samples to rapidly screen samples from stranded marine mammals for the presence of pathogens such as Brucella, which can also infect people. Also, we are refining and validating assays to evaluate a broad spectrum of reproductive and stress hormones from marine mammal blubber.
Regions of Study: Atlantic Seaboard, Gulf of Mexico
Primary Contact: Lori Schwacke
Coastal Pollution (Chemical Contaminants, Pathogens and Microbes)
Related NCCOS Center: HML
- Mancia A., Lundqvist M.L., Romano T.A., et al. 2007. A dolphin peripheral blood leukocyte cDNA microarray for studies of immune function and stress reactions. Dev Comp Immunol. 31(5):520–529.
- Mancia A., Warr G.W., Almeida J.S., et al. 2010. Transcriptome Profiles: Diagnostic Signature of Dolphin Populations. Estuaries and Coasts. 33(4):919–929.
- Kucklick J.R., Schwacke L.S., Wells R.S., et al. 2011. Bottlenose dolphins as indicators of persistent organic pollutants in waters along the U.S. east and Gulf of Mexico coasts. Environmental Science & Technology. 45(10):4270–4277.
- Mancia A., Ryan J.C., Chapman R.W., et al. 2012. Health status, infection and disease in California sea lions (Zalophus californianus) studied using a canine microarray platform and machine-learning approaches. Dev Comp Immunol. 36(4):629–637.
- Schwacke LH, Zolman ES, Balmer BC, et al. 2012. Anemia, hypothyroidism and immune suppression associated with PCB exposure in bottlenose dolphins (Tursiops truncatus). Proceedings of the Royal Society: Biological Sciences. 279:48–57.