Climate change threatens U.S. estuaries

The national study, Climate Sensitivity of the National Estuarine Research Reserve System, points to three East Coast reserves (Sapelo Island NERR in Georgia, ACE Basin NERR in South Carolina and Waquoit Bay NERR in Massachusetts) and the Tijuana River NERR on the California-Mexico border as the most sensitive to climate change.

Estuaries are places where rivers meet the sea, providing nursery habitat for fish and shellfish while buffering many coastal communities from the impacts of coastal storms and sea level rise. The climate exposure of each reserve provides 'first alarm' indicators about the effects of climate change on coastal ecosystems. Ongoing research at each of the reserves provides real-time data about how climate change impacts these important natural resources.

Researchers determined the extent of relative climate sensitivity in the reserves by looking at five factors: social, biophysical, and ecological sensitivity, and exposure to temperature change and sea level rise.

Key Findings

• Reserve ecological resilience was examined and the key underlying estuarine stressors were found to be toxic pollutants, storm impacts, invasive species, habitat fragmentation, sedimentation, and shoreline erosion. The most frequently identified factors contributing to these stressors included residential development, land use, population growth, wastewater treatment and sea level rise.
• High social sensitivity to climate change was indicated where there is higher employment within natural resource-dependent industries, lower per capita income and median home values, higher percentages of minority populations, and a higher percentage of individuals lacking a high school education. Social sensitivity to climate change was generally highest in the southern portions of the East and West coasts of the U.S., the Gulf of Mexico, and Alaska.
• Biophysical sensitivity summarizes each reserve's relationship between annual spring atmospheric temperature, rainfall data, and water quality factors such as water temperature, dissolved oxygen, and pH. Temperature change exposure risk was greatest for reserves located in the Great Lakes, Gulf of Mexico, Mid-Atlantic, and Northeast regions of the country, while reserves in the Gulf of Mexico, parts of the Mid-Atlantic, Southeast, California, and Oregon showed the greatest risk of sea level rise exposure.

For further information, see http://oceanservice.noaa.gov/news/weeklynews/aug13/nerrs-climate-report.html