Recognizing Coral Adaptations to Environmental Stressors, National Park of American Samoa
Ofu Lagoon, part of the National Park of American Samoa, contains a healthy coral reef habitat that supports a diversity of species. The park is working with university partners towards the goal of understanding the unique adaptations of the coral in Ofu Lagoon to multiple environmental stressors associated with climate change.
The coral reefs in and around the park support more than 975 fish species and 250 coral species, and a high diversity of invertebrates. Disturbances such as cyclones are expected to increase with climate change, but the principal threat to coral reefs is global warming, which increases nearshore water temperatures and, in turn, increases coral disease and coral bleaching events. Coral reefs within the park and worldwide are expected to experience substantial mortality, up to 90% loss by the end of the century. Ocean acidification, which is caused by increased levels of carbon dioxide in the atmosphere, prevents corals from absorbing the calcium carbonate they need to maintain their skeletons, and dissolves the stony skeletons that support corals and reefs.
The park works closely with territorial government agencies and advisory groups to develop solutions to concerns related to coral reef health and expected impacts of climate change. This is not only an effective collaboration but it is also necessary, because the park leases rather than owns the lands and waters within its boundaries, and so must negotiate management plans and actions with traditional landowners and village councils in addition to American Samoa government agencies.
Outcomes and Conclusions
Results of these studies help the park in planning long-term management efforts, such as identifying new candidates for marine protected areas. It would be most effective to target areas that are expected to have higher resiliency to climate change provided that other locally controlled stressors (such as destructive fishing practices) are reduced; examples include shaded areas at the base of cliffs, and reef edges that experience cold-water upwelling events. Although actions such as shading and cool-water discharge would not allow coral to adapt to changing conditions or slow climate change, these strategies could be implemented for short-term solutions, such as briefly protecting small areas of reef, while longer-term management decisions are resolved.
This case study is part of the 2015 National Park Service report, Coastal Adaptation Strategies: Case Studies. These case studies initially were developed by park managers as part of a NPS-led coastal adaptation training in May 2012. The case studies follow the format created for EcoAdapt’s Climate Adaptation Knowledge Exchange (CAKE) database, including a list of adaptation strategies. All case studies were updated and modified in September 2013 and March 2015 in response to a growing number of requests from coastal parks and other coastal management agencies looking for examples of climate change adaptation strategies for natural and cultural resources and assets along their ocean, lacustrine, and riverine coasts.
Clark, T. (2015). Recognizing Coral Adaptations to Environmental Stressors, National Park of American Samoa [Case study on a project of the National Park of American Samoa]. Excerpted from Schupp, C.A., R.L. Beavers, and M.A. Caffrey [eds.]. 2015. Coastal Adaptation Strategies: Case Studies. NPS 999/129700. National Park Service, Fort Collins, Colorado. Retrieved from CAKE: www.cakex.org/case-studies/recognizing-coral-adaptations-environmental-s...(Last updated November 2015)