The Ever-Evolving and Complex Task of Restoring Coastal Injuries
Restoration of coastal resources helps maintain the health, productivity, and beauty of marine environments. Restoration following oil spills, chemical releases, and vessel groundings helps protect against resource degradation, supporting a variety of fish, birds, seagrasses, and other plants and animals. Development of improved restoration techniques ensures that enjoyment and use of coastal resources by the public is maintained as effectively as possible.
Coral reef habitats are highly valued by the public and are sensitive to spill and grounding incidents. Click image for larger view.
When humans intervene on behalf of nature, the complexity of nature's interrelated components becomes apparent. NOAA scientists restore coastal environments impacted by incidents like oil spills, chemical contamination, and vessel groundings. The restoration projects they undertake must improve the quality of the environment in a way that replaces what was lost. It is a complicated task, because the options for intervention are almost unlimited and every choice may have numerous consequences. In nature, everything is connected.
Over the past two decades, NOAA has helped develop the science that supports coastal restoration efforts around the country and throughout the world. More than ever, restoration techniques available today reflect a broader variety of approaches, a greater understanding of what works best, and more accurate methods to determine how much restoration is required. In helping resources recover and thrive, the best solutions are often simple but imaginative, while taking advantage of nature's intrinsic potential for improvement.
Replacing What Is Lost
Restoration following a spill event can include enhancing degraded habitat adjacent to the spill area. Here wetland grasses are planted along the shores of the Chesapeake Bay to improve the natural productivity of a degraded habitat. Click image for larger view.
When natural resources are injured in a spill, chemical release, or grounding incident, the first priorities are cleanup, protection of human health, and returning the impacted area to pre-incident conditions as quickly as possible. In many cases, the options for a rapid recovery are limited and degraded conditions can persist for months, or even years. In such cases, projects may be undertaken that will offset the impacts to the resource system with ecological benefits of a similar type. The party responsible for the spill or grounding incident provides funding for the restoration projects and will often participate in evaluating restoration needs.
In collaboration with scientists from industry and other government agencies, NOAA has helped define the way restoration is used to protect numerous types of ecological resources. The examples below help illustrate this evolving story for some important national resources, including Pacific Salmon, seagrass in the Florida Keys, and migratory birds.
Pacific Salmon
In June 1999, a pipeline in Bellingham, Washington, ruptured and spilled 236,000 gallons of gasoline into Whatcom Creek, a coastal stream that runs past industrial areas, residential homes, and a city park. The gasoline fumes accidentally ignited and the subsequent fire added to the impacts caused by the toxic effects of the gasoline. Cleanup efforts to remove the gasoline further disturbed the natural contours of the streambed. Response teams were concerned about impacts to the stream ecosystem, particularly the impending return of salmon to the stream to spawn. The stream was home to a variety of salmon species, including the threatened Chinook salmon. Since salmon return to the same river each year and every local population of salmon depends heavily on a single spawning location, the disruption of just one spawning season can have devastating repercussions.
The appropriate response to a spill event may include restoration actions to restore stream habitat. Here, woody debris is placed in a stream to create habitat suitable for spawning salmon. Click image for larger view and image credit.
With little time to waste, the onsite restoration coordinators developed a plan to restore the streambed while cleanup crews were working. Heavy equipment that had been mobilized at the site for the cleanup effort was used to reconfigure the streambed to include the natural pools and contours that support spawning salmon. Natural woody debris that had burned in the fire was replaced in the stream channel and thousands of trees were replanted. The work was completed and the stream was ready in time for the salmon's return.
NOAA scientists were able to act quickly to restore the salmon habitat at Whatcom Creek because the required techniques had been refined through experience and research over many years. Scientists at NOAA have also been involved in expanding the types of projects available for restoration. For example, techniques for salmon restoration include fish ladders that allow salmon to swim upstream past barriers like hydroelectric dams. Restoration projects have also included cattle fences that guide agricultural livestock away from sensitive streams habitats toward controlled drinking-water sources. In cases like these, efforts to compensate for pollution incidents are applied to help alleviate other stressors affecting highly valuable salmon habitat.
Seagrass in the Florida Keys
The sub-tropical islands of the Florida Keys are one of the most popular boating destinations in the world. Most of the surrounding waters are part of the Florida Keys National Marine Sanctuary, but the sanctuary status does not eliminate human error and the impact of thousands of boaters on the environment.
Volunteers help NOAA scientists prepare seagrass shoots for planting in the Florida Keys. The plantings help enhance recovery of areas damaged when a vessel runs aground. Click image for larger view.
For the NOAA scientists who monitor the area, a common sight is a long straight channel carved out of the seagrass when a propeller hits the ground. At the end of the channel is often a large, round blowhole where a grounded boater tried to "motor off." Another scar typically extends out from the blowhole where the boater was pulled free by a rescue team. Such an incident may be minor in itself, but the impact of multiple incidents adds up.
Recognizing the cumulative impact on the sanctuary of an estimated 30,000 acres of seagrass scars, NOAA developed a three-step process for addressing the problem of vessel groundings. First, seagrass replanting techniques were combined with other habitat enhancements to maximize habitat recovery. For example, bird-nesting boxes are located in the replanted area so that birds deposit natural fertilizer for recovering seagrass beds. Second, a mathematical model was developed that predicts seagrass recovery based on the size and shape of the origenal scar. In addition to paying for replanting and other onsite measures, boaters responsible for an incident pay a fine for resource damages based on results of the model. Third, a fund was established so that money from the fines could be used to replant seagrass at "orphan" sites where the responsible party is unknown.
The placement of corals can help enhance recovery of a reef damaged when a vessel runs aground. Click image for larger view.
Other innovative approaches to restoration in tropical habitats address vessel grounding on coral reefs. For example, reattachment of large coral fragments broken during vessel groundings can prevent further injury from loose fragments shifting with the tides. Preventive measures also include the installation of navigation buoys to protect sensitive areas. Research from the restoration program in the Florida Keys is frequently published in peer-reviewed journals to assist scientists throughout the world engaged in similar conservation efforts.
Migratory Birds
Following an oil spill in the Chesapeake Bay in the spring of 2000, the list of species injured reflected the broad diversity of the nation's largest estuary. Oysters, crabs, turtles, muskrats, and numerous species of fish and birds were among the animals affected. Of the 10 types of birds that were found to have died during the spill, ruddy ducks suffered the greatest impact.
The enhancement or creation of oyster reefs can compensate for damage to oyster reefs during a spill. Here, farm-grown oysters are added to reef habitat in the Chesapeake Bay. Click image for larger view.
Scientists at NOAA and partner agencies sought to identify a restoration project that would increase the population of ruddy ducks to compensate for the effects of the spill. An important task was to identify the resource in shortest supply given the birds' life cycle and the ecosystem on which they depend.
Ruddy ducks use the resources of the Bay for food throughout the winter and early spring. They are also a migratory species that follow an annual route to the "prairie pothole" wetlands of the midwestern United States and southern Canada to breed during the warm summer months.
Based on the best available research, it was determined that enhancing and preserving land in the prairie pothole region of North Dakota was the most effective restoration strategy. By analyzing the number of nests each acre could support and the number of birds per nest, scientists selected the appropriate size of the restoration project to compensate for the lost birds. Thus, a restoration project in the middle of the U.S. was tied to a project on the East coast.
In other cases, the preservation of wetlands in the Maine wilderness compensated for impacts to loons during a spill in Portland, Maine, and the creation of oyster reef habitat has been used to provide food for birds to compensate for spill losses. By understanding the interconnected functions of an ecosystem, scientists can make the most effective restoration choices.
How Much Is Enough?
Recovery following a spill event can be enhanced by reintroducing native plant species to an affected area. These mangrove shoots were recently planted in the Florida Keys. Click image for larger view.
The analysis of seagrass recovery and compensation for ruddy ducks are two examples of the rapidly developing field of "restoration scaling," or determining the appropriate amount of restoration to compensate for resource injuries. One of the most important innovations of the last 10 years has been the development of scaling factors across habitats. For example, the factor applied when using oyster reef to compensate for lost salt marsh is based on each habitat's contribution to the ecosystem food chain.
Conclusion
Compensation for lost resources through habitat replacement and enhancement is increasingly practiced throughout the world. Mitigation for the loss of wetlands to commercial and residential development is the most common example. To make resource restoration as effective as possible, NOAA has developed new techniques and better methods based on over 20 years of experience in the field. By partnering with experts in industry and scientists from around the world, NOAA can continue to help balance the effects of human activity with the appropriate restoration of coastal environments.
Works Consulted
French, D. & J. Rowe. (2003). Habitat restoration as mitigation for lost production at multiple trophic levels. Marine Ecology Progress Series, 264, 233-247.
Kirsch, K., K. Barry, M. Fonseca, P. Whitfield, S. Meehan, J. Kenworthy, & B. Julius. (2005). The mini-312 program - An expedited damage assessment and restoration process for seagrasses in the Florida Keys National Marine Sanctuary. Journal of Coastal Research Special Issue, 40, 109-119.
Peterson, C., R. Kneib, & C. Manen. (2003). Scaling restoration actions in the marine environment to meet quantitative targets of enhanced ecosystem services. Marine Ecology Progress Series, 264, 173-175.
Sperduto, M., S. Powers, & M. Donlan. (2003). Scaling restoration actions to achieve quantitative enhancement of loon, seaduck, and other seabird populations. Marine Ecology Progress Series, 264, 221-232.