As polar bears move into closer proximity with humans, oil and gas developers working in the arctic may soon find themselves working near protected polar bear populations. Battelle has developed new environmental DNA (eDNA) collection methods to allow scientists to monitor polar bear populations using DNA left behind in their paw prints. A new study for the North Slope Borough of Alaska will validate eDNA methods for monitoring polar bear activity.
eDNA is DNA collected from cells or excretions left behind in water or sediments rather than collected from live animals. As animals move through the environment, they shed hair and skin cells and leave behind traces of DNA in urine, saliva and feces. Researchers can extract and sequence the DNA in environmental samples to determine what species are present or have passed through the area, from microbes to large animals. It allows for faster, easier and more cost-effective data collection for required biodiversity studies and environmental monitoring.
Battelle has already used genomics, including eDNA sampling methods, to monitor marine mammals including bowhead whales and gray whales. Genomic studies of bowhead whales, conducted on behalf of the North Slope Borough, were used to inform hunting quotas for indigenous villagers as well as oil & gas development activities. Similar studies are currently underway to provide new insights into gray whale population diversity and migration. Oil & gas companies can use data from eDNA studies to plan development activities and monitor environmental impact on protected species.
Current eDNA methods extract DNA from marine or freshwater environmental samples. This limits their utility for monitoring the movement of animals on land. Battelle has pioneered new methods that would allow DNA to be extracted from polar bear paw prints in snow. Snow samples from the paw prints are melted before extracting and amplifying DNA for analysis. This approach also promises to be transferrable to studies of non-aquatic species such as terrestrial bears.
DNA fingerprinting methods for polar bears are being developed using polar bear blood samples and environmental samples provided by the Columbus Zoo. The samples will be used to develop primers that can detect the presence of polar bears and to identify genetic loci (SNPs) that can be used to fingerprint individual bears. This will allow researchers to answer questions about population size, range and genetic variability to inform conservation efforts.
The North Slope Borough study begins this fall. In phase one, researchers will validate the eDNA collection methods. Phase two includes demonstration and validation of the DNA fingerprinting methods to track individual bears. Ultimately, data will be collected in order to estimate population size and set appropriate hunting quota limits for hunts conducted by the Eskimos in the North Slope. Indigenous populations in Alaska, Canada and parts of Russia depend on the bears for subsistence and ceremonial hunts in their traditional way of life.
Studies of polar bear genomics could help researchers monitor the success of conservation efforts and international treaties aimed at protecting polar bears. Polar bears are considered to be especially vulnerable to the effects of climate change. However, many polar bear populations have not been thoroughly studied, making it difficult to monitor changes in population size or genetic variability over time. eDNA studies could help to fill in some of these knowledge gaps by making it faster, safer and cheaper to gather genomic data.
Battelle scientists are continuing to study and validate new eDNA methods. Eventually, researchers hope to use similar methods to extract DNA from soil samples, further expanding the range over which land animals could be monitored and the species that could be studied.