The ocean might as well be Mars. Like astronomers grasping at ways to identify life on a distant planet, marine scientists have no easy method for detecting sea creatures’ presence in the vast watery realm.
An emerging technique – analyzing DNA in skin, scales and feces animals leave behind – has shown promise for revealing hidden ecosystems on land and in fresh water. But deep ocean environments have largely proven too complex for the approach. Now, Stanford scientists show progress in using this analysis to overcome complicated water movements and other obstacles to detect ocean animals in locations where the water can be more than 7,200 feet deep.
“We want to know what’s out there,” said study lead author Elizabeth A. Andruszkiewicz, a graduate student in Stanford’s Department of Civil and Environmental Engineering. “Eventually, this technology may answer bigger questions, such as how communities of organisms have adapted to environmental changes over time.”
The Stanford-led study also marks the first time the approach has been used in the deep waters of Monterey Bay, an important ecosystem in the California Current, which flows southward along the western coast of North America. In addition to being highly productive ecosystems, these areas have been the focus of relatively intensive ongoing research by institutions such as the Monterey Bay Aquarium Research Institute (a partner in the study). The resulting archived water samples and long-term data-sets present unique opportunities for e-DNA analysis of ecological change over time.
Collecting e-DNA is fairly straightforward – a basic water sample does the trick – and scientists can archive these samples for long periods by freezing them. The approach promises a faster, more comprehensive and less invasive way to measure abundance and distribution of organisms. It might also be able to detect invasive species or changes in the distribution of endangered species.
