Aquatic Biodiversity

We mapped patterns of aquatic biodiversity at regional and national scales to compare them with threats from climate change and land management. We also defined and mapped forest-associated fishes across the United States.

To facilitate aquatic invasive species monitoring at a regional scale, we developed multispecies eDNA field methods, laboratory analysis, and sample design. We then conducted a pilot project in large rivers, lakes and reservoirs on the east and west sides of the Cascade Range in Oregon to assess these newly developed field methods.

Aquatic biodiversity is a critical element of national-scale environmental protection and planning. The Southeastern United States is a global hotspot for aquatic biodiversity.

The Southeastern United States has the highest aquatic biodiversity across the conterminous 48 states. This region is a global biodiversity hotspot, particularly for crayfish and mussels but also for salamanders and turtles, which were not considered in our work. Imperiled aquatic species follow broader patterns of aquatic biota, with greater numbers of species listed under the U.S. Endangered Species Act occurring in the Southeast and Pacific Northwest.

The number of fish, crayfish, and freshwater mussel species listed under the Endangered Species Act by watershed across the conterminous United States.

Biodiversity of forest-associated fishes is greatest east of the Mississippi River.

Forest-associated fish species richness by watershed (hydrologic unit code 8), with darker shades symbolizing more species. (A) Fish species associated with areas having relatively low forest cover (26 to 50 percent). (B) Fish species associated with areas having moderate to high forest cover (51 to 75 percent). (C) Fish species that have more than three-quarters of their distribution in watersheds with very high forest cover (76 to 100 percent). Figure from Bury et al. (2021).

Environmental DNA Results: We developed field and laboratory methods for detecting plant and animal DNA from the same water sample. Primers were developed for 20 invasive taxa of particular interest to the Pacific Northwest Region of the USDA Forest Service. We found that field sampling successfully detected invasive plants and animals, thus providing a new method that can be applied across the region to detect invasive aquatic species much earlier than previously possible.

Focusing on forest-associated aquatic biodiversity provides foundational information for national- and local-scale planning for protection and conservation of biota.

Theoretical and applied work on aquatic biodiversity leverages emerging technology directly relevant to long-term monitoring and adaptive management. Multispecies environmental DNA field and laboratory methods for aquatic invasive species directly support the development and implementation of monitoring applications at a regional scale. Early detection allows for early eradication of aquatic invasive species. To intercept invasive species before they are fully established, sensitive environmental DNA samples can be taken to provide a foundation for monitoring that facilitates early detection and a rapid response.

Technicians filter water samples from Cow Creek, Oregon, to capture DNA from aquatic organisms. The DNA-laden filters were later processed in a laboratory to identify which species were present in the river. Figure from Flitcroft et al. (2018).

Collaborators

• Gwendolynn Bury (Oak Ridge Institute for Science and Education)

• U.S. Geological Survey

• USDA Forest Service Pacific Northwest Region

• Oregon State University