| "Within weeks the place was already being used by shorebirds and colonized by invertebrates." | |
| Craig Cornu, South Slough National Estuarine Research Reserve |
|
When left alone, nature will eventually reclaim habitats altered by humans, but coastal resource managers are always looking for ways to speed up that process. Researchers in Oregon have undertaken a three-phase project using conventional and experimental techniques to accelerate salt marsh restoration.
"We were in a situation where we knew we wanted to do restoration because we have degraded lands," says Craig Cornu, stewardship program coordinator at South Slough National Estuarine Research Reserve in Charleston, Oregon. "What we wanted to do was restore these sites and learn as much as we could about accelerating the process."
The degraded lands Cornu refers to are former salt marshes that were diked and converted into pasture around the turn of the century. "By the time the Reserve was formed, the pastures had mostly been abandoned," Cornu explains. "In some areas, dikes and tidegates were deteriorating and tide waters were finding their way into the converted areas. This naturally started the conversion back to salt marsh."
But at some sites, natural recovery had been underway for 50 years, he notes, and "these areas just weren't as productive as one would think" after that length of time. To speed the recovery, the Winchester Tidelands Restoration Project was developed in 1993. The Reserve assembled an advisory group for the project that included experts from universities, agencies, and private industry. The group mapped out a three-phase strategy for restoring the salt marshes.
After receiving a grant from the U.S. Fish and Wildlife Service, staff began working on the first phase of the experiment, which called for using the material from the dikes to re-grade the marsh surface to three elevations to determine which elevation was most conducive to accelerated development. The top 12 inches of soil and grasses were to be removed, set aside, and re-spread after the 12-acre site was graded. The tide water would then be allowed to create its own channels. "None of this was particularly technical," Cornu says, "but it had never been tried before on this scale."
Construction was completed in 1996, and Cornu says the results looked like "scorched earth. We were expecting it to lay dormant the first winter and not be much use to anything. To the contrary, things started happening very quickly. Within weeks the place was already being used by shorebirds and colonized by invertebrates."
Cornu says the purpose of the restoration project, which will have all three phases complete by summer 2000, is to "test different techniques and push the envelope on how restoration is being done and how we can transfer that information to coastal managers. We hope that coastal managers will take what we've done and look at it critically to see if any of it will apply to their situation."
For more information on South Slough's Winchester Tidelands Restoration Project, contact Craig Cornu at (541) 888-5558, or e-mail him at cornu@harborside.com.
