National Aeronautics and Space Administration

Coastal Managment

Earth's coastal regions are a precious natural resource--the United States alone has over 95,000 miles of shoreline. In recent years, there has been a significant increase in the human population in these coastal areas. The coasts are also home for a wide variety of birds, animals, and vegetation. To assure the continued vitality of these coastal regions, we need to understand how human activities along the coast are impacting the natural ecosystems in these areas. Collecting accurate and timely information can help us understand how our coasts are changing with time and what impact these changes have on the larger global environment.

Image: A red tide bloom has waxed and waned along Florida' southwestern coastline for months, dating back to late 2001. As recently as March 1, 2002, high concentrations of Karenia brevis were located along the Lee County and Collier County shorelines. In-water measurements revealed there are more than 1 million cells of the algae per liter of water--a level at which the organism become highly toxic to fish and shellfish in the area. This true-color image was acquired by the Moderate-resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra satellite, on February 17, 2002.

Our coasts are affected by a number of natural phenomena. In recent years, the level of the sea has risen, threatening both the natural environment and human activities along the coasts. The incidence of harmful algal blooms (HAB) and hypoxia has also increased. These phenomena may be caused by excess nutrient concentrations from coastal runoff and are depriving our waters of dissolved oxygen, affecting marine ecosystems and coastal economies. Over 7000 square miles of the Gulf of Mexico are hypoxic--the largest swath in the Western Hemisphere.

NASA researchers are making significant contributions to understanding these potentially harmful phenomena and better quantifying how they impact coastal regions. NASA partners with the Naval Research Laboratory (NRL), the Environmental Protection Agency (EPA) and the National Oceanic and Atmospheric Administration (NOAA) on these efforts. NOAA has developed models that simulate the oceanic environment and are used to forecast the occurrence of these harmful phenomena. These forecasts require data on environmental conditions such as sea surface temperature, sea surface height, salinity, etc., as input, and NASA's Earth science missions routinely provide this type of information for NOAA.

The latest remote sensing data from NASA's Jason-1 satellite show normal conditions across the equatorial Pacific. The image above is a global map of sea surface height, accurate to within 30 millimeters. The image represents data collected and composited over a 10-day period, ending on Nov. 3, 2003.

NASA has a long heritage of collecting data for ocean research. It continues to this day with missions such as Terra and Aqua, which both fly the Moderate Resolution Imaging Spectroradiometer (MODIS). Numerous other missions provide additional important information for coastal management issues, including Jason-1, GRACE, the Ice Clouds and land Elevation Satellite (ICESat), and the SeaWinds instrument on QuikSCAT. Data collection will continue in the coming decade as additional missions launch including the next generation of Earth-observing missions, known as the National Polar-orbiting Operational Environmental Satellite System (NPP). NPP will be a series of joint Department of Defense (DoD), NASA, and NOAA missions, scheduled for operation around the end of this decade.

As the decade progresses and more information from NASA satellite measurements are incorporated into science models, their ability to realistically simulate conditions in the Earth's seas will improve. As a result, predictions of sea level change will become increasingly detailed and accurate over the next few years. Similarly, by decade's end, it should also be possible to predict outbreaks of HAB and hypoxia several days in advance of their occurrence and to have much more detailed and accurate information about the severity and the duration of any given outbreak. These improved simulations become the input to decision tools used for coastal management decisions. Armed with this new information, coastal communities will be better prepared to plan for and mitigate the impacts of the sea level change and other coastal hazards, and will be increasingly able to issue advanced warnings for outbreaks of hypoxia and HAB and accurately predict how long the coastal areas will be impacted.