MSL's approach to eelgrass is spreading
More than 60 percent of the world's population lives near the coast. In addition to the growing development and economic importance of coastal areas, there is a major push for maintaining and restoring coastal ecosystems.
Sustainable development, which once might have focused on maintaining an ecosystem, has blossomed into net ecosystem improvement, or restoring an ecosystem to "better" than its existing state.
This is the focus of the restoration team at PNNL's Marine Sciences Laboratory. "There are so many factors influencing plant restoration success that you can't control," said Ron Thom, who heads MSL's restoration work. "To deal with this uncertainty, we have to plan a net increase in ecosystem function on our projects."
To ensure the effectiveness of MSL's restoration work, Thom and his colleagues have developed a process for working with eelgrass--which is critical for providing shelter and food to young salmon and many other saltwater fish--that maximizes the probability of success. "Our whole program is set up in the adaptive management framework, that is, learn by doing and at the same time, acknowledge up front that there's uncertainty," Thom said.
Adaptive management is not a new concept, Thom said, but its application to habitat restoration is new. "MSL developed guidance on how to use adaptive management that is now being used nationally for restoration. It's not necessarily our specific methods, but adaptive management principles are now being applied to restoration programs in the Mississippi Delta and Florida Everglades."
Thom and his team are pioneers in developing an understanding of growth requirements for eelgrass in the Northwest. They assess each potential site to see if it is suitable to grow the plant. If the probability of eelgrass success is high or moderate based on site assessment, researchers will plant.
The site is monitored with adaptive management principles in mind. "We're shooting for a certain goal but we may not make it because there are things we're uncertain about. So we set up alternatives up front and use monitoring to tell us which alternatives we'll need," Thom said.
Experimental alternatives are part of the adaptive management process. For example, the Washington State Department of Transportation recently called on experts from MSL and the University of Washington to minimize eelgrass destruction when it expanded the Clinton Ferry dock. Previous attempts to preserve existing eelgrass and replant beds destroyed by construction had often failed, but scientists' understanding of eelgrass plant needs led to a creative solution.
Scientists suggested dock designers put glass blocks in the dock's walkways. They also advised the underside of the dock be painted with a bright reflective coating. Both suggestions were designed to increase the amount of light the transplanted eelgrass plants receive.
Thom and his team salvaged eelgrass from the site before construction began and planted it in tanks at MSL, raising about 30,000 eelgrass starts. Later they replanted the dock area and a similar area for reference.
The ferry terminal project is a success. Scientists count 18,000 more eelgrass plants today than before dock expansion, a huge improvement.