Conducting a census of species using environmental DNA.
Tracking down species with DNA. I’m Bob Hirshon and this is Science Update.
Anything that walks, hops, swims, or slithers through an environment leaves a trail of DNA from skin, hair, and other cells left behind. Using DNA amplification techniques, scientists can now take small samples of soil or water, and identify every living creature in that environment. That’s what molecular ecologist Abbey Paulson is doing at a variety of sites in Acadia National Park in Maine.
This research will establish a baseline level of biodiversity in the park: so what species are here and at what abundances. And that will let us gauge into the future, as climate change happens and other global change phenomena, how those things are affecting the communities and ecosystems in the park.
That information will help national park staff make better decisions on how to protect and preserve park resources. I’m Bob Hirshon, for AAAS, the science society.
Making Sense of the Research
Dr. Elizabeth "Abbey" Paulson, whose research is featured in this Science Update, received the first Second Century Stewardship Science Fellowship by the Schoodic Institute in July 2016. Her research focuses on the environmental DNA analysis of various habitats in Acadia National Park.
So what exactly is Paulson studying? She is studying the three types of ecosystems at Acadia National Park—soil, intertidal, and freshwater—to try to understand the biodiversity across Acadia’s Mount Desert Island, the Schoodic Peninsula, and Isle au Haut.
Intertidal communities are those where organisms live between the low and high tide lines. At low tide, the intertidal zone is exposed whereas at high tide, the intertidal area is underwater. Intertidal ecologists, therefore, study the interactions between intertidal organisms and their environment.
In order to try to track this biodiversity, Paulson is analyzing the DNA traces left behind by the organisms that have been in the area. This process is called environmental DNA surveying—or eDNA—and it relies on a relatively new technology that is just beginning to be applied in environmental research. eDNA—defined here as genetic material obtained directly from environmental samples (soil, sediment, water, etc.) without any obvious signs of biological source material—is an efficient, non-invasive, and easy-to-standardize sampling approach. Coupled with sensitive, cost-efficient, and ever-advancing DNA sequencing technology, it may be an appropriate candidate for the challenge of biodiversity monitoring.
Environmental DNA surveying seeks to overcome some of the drawbacks to traditional environmental monitoring, including difficulty in tellling apart closely related species and unintended harm to habitats or species. These traditional techniques have sometimes resulted in flawed species databases.
By doing the environmental DNA surverying, Paulson hopes to capture a genetic snapshot of biodiversity. This baseline data can then be compared with earlier biodiversity surveys, some of which date back 100 years. Ultimately, the information that Paulson is gathering can help to guide specific park-management and conservation practices, such as culvert maintenance and planning.
Now try and answer these questions:
- Where is Abbey Paulson conducting her research? Why?
- What technique is Dr. Paulson using in her research?
- What three types of ecosystems is Dr. Paulson studying?
- What are intertidal communities?
- How does eDNA overcome some of the drawbacks of traditional environmentl monitoring?
You can check out the Bird Migration & Climate Change Science Update to learn more about other research that is taking place at Acadia National Park.
The fellowship that Dr. Paulson received is part of a partnership between the Schoodic Institute and the American Association for the Advancement of Science (AAAS). This research supports the goals of the Second Century Stewardship Partnership, with a focus on research relevant to informing stewardship and management of Acadia National Park and the potential to advance science education, communication, and public engagement.
This Science Update can be used to show your students the type of work being conducted by scientists out in the field. It's a good example of how different kinds of people are involved in scientific research and that it isn't always conducted in a laboratory. It would be a good lesson to use to help address learning goals in the Nature of Science chapter of Benchmarks for Science Literacy.
To help extend the ideas in this Science Update by having your students listen to All Species Inventory, which looks at the field of taxonomy, one of the oldest practices in biology, and how a group of scientists and Silicon Valley entrepreneurs is trying to bring it into the twenty-first century.
Plants 1: Plant Parents
6-8 | Hands-On
Identification and Classification of Grassland Plants
Genes, Environments, and Behavior 1
Preserving Health through Biological Diversity
Using Field Notebooks for Biodiversity Study
9-12 | Hands-On