NOAA 2001-011
Contact: Connie Barclay

Coral Reefs, Wetlands, Shoreline Communities and Fisheries Under Threat Due To Potential Impacts Of Climate Change

The National Oceanic and Atmospheric Administration's National Ocean Service released a new report titled, "The Potential Impacts of Climate Change on Coastal and Marine Resources," that concludes that climate changes in this century may have serious implications for U.S. coastal and marine resources.

NOAA scientists are concerned. With a coastline of over 95,000 miles and a dependency on the essential goods and services that it provides, the adaptation of the marine environment to climate change is important. According to scientists, climate change will add to the stresses already occurring to coastal and marine resources, as a result of increasing coastal populations, development pressure and habitat loss, over fishing, nutrient enrichment, pollution and invasive species.

"While there are still important uncertainties associated with the assessment, it is clear that critical coastal ecosystems - like corals, wetlands and estuaries - are becoming increasingly stressed by human activities," said Margaret Davidson, acting assistant administrator for NOAA's National Ocean Service. "The climate-related stresses described in the report will certainly add to their vulnerability."

The report, prepared as part of the U.S. Global Change Research Program's National Assessment of the Potential Consequences of Climate Variability and Change, compiles scientific studies by representatives of government, the private sector and academia, to evaluate the implications of both existing climate variability and future climate change on U.S. coastal and marine resources.

"Looking at the findings of this important report, scientists believe it is critical that we integrate human activities with climate changes, in order to minimize future impacts on coastal and marine resources," said NOAA Administrator D. James Baker. "It is very important for those Americans, who are or will likely be effected by climate impacts, to be aware of the risks and potential consequences that future change will pose to their communities and their livelihoods."

The report highlights key issues of climate change - shoreline erosion and human communities, threats to estuarine health, coastal wetland survival, coral reef die-offs, and stresses on marine fisheries. It also addresses that coral reefs are already under severe stress from human activities and high ocean temperatures associated with severe El Niño/southern oscillation events. According to the report, corals have experienced unprecedented increases in the extent of bleaching, emergent coral diseases, and widespread die-offs in recent years. The direct impact of increasing atmospheric carbon dioxide on ocean chemistry is likely to severely inhibit the ability of coral reefs to grow and persist in the future, further threatening these already vulnerable ecosystems.

Globally averaged, sea-level will continue to rise, and the developed nature of many coastlines will make both human settlements and ecosystems more vulnerable to flooding and inundation. Barrier islands are especially vulnerable to the combined effects of sea-level rise and uncontrolled development that hinders or prevents migration. Ultimately, choices will have to be made between the protection of human settlements and the protection of coastal ecosystems such as beaches, barrier islands and coastal wetlands.

Increases in precipitation and runoff are likely to intensify stresses on estuaries in some regions, by intensifying the transport of nutrients and contaminants to coastal ecosystems. As rivers and streams also deliver sediments, which provide material for soil in wetlands and sand in beaches and shorelines, dramatic declines in stream flows could, on the other hand, have negative effects on these systems.

Changes in ocean temperatures, currents and productivity will affect the distribution, abundance and productivity of marine populations, with unpredictable consequences to marine ecosystems and fisheries. Increasing carbon dioxide levels could also trigger abrupt changes in thermohaline ocean circulation, circulation driven by differences in the density of sea water, controlled by the effects of temperature and salinity. This can result in massive and severe consequences for the oceans and for global climate. Extreme and ongoing declines in the thickness and extent of Arctic sea ice will have enormous consequences for Arctic ecosystems.

"Most coastal resource management programs are not yet taking climate change into account in their goals and plans," said Donald F. Boesch, Ph.D., the other co-chair of the assessment and president of the University of Maryland Center for Environmental Science. "With the scientific consensus that there is now clear evidence of a changing climate, these programs should clearly begin to take into account the environmental changes that are possible over the next several decades."