chapter  4
32 Pages

## Habitat

The ecosystems that occur between the ocean and the land are some of the most productive on Earth. Similarly, they are very important sites for carbon sequestration, and they account for half of the carbon sequestration that resides in ocean sediments (Duarte 2009). Yet, they are also some of the most imperiled. Worldwide, there is about 1-2% loss of coastal salt marshes each year (Achard et al. 2002). Although the coasts of the world are extensive, the size of natural coastal ecosystems is shrinking at an alarming rate, mainly because of human development, nitrification, contaminants, and natural geophysical processes. The major drivers are land reclamation, aquaculture, excessive sedimentation, nutrient and organic inputs, coastal hypoxia, and a combination of sea level rise and subsidence. Even the ecosystem below the water surface of estuaries and bays is imperiled. Sea grasses-referred to generally as submerged aquatic vegetation-that support fish and shellfish nurseries are declining in both tropical and temperate waters (Green and Short 2003; Fertig et al. 2013). Conservation of these fragile environments is essential for the protection of avian communities and the other components of coastal communities (Boersma et al. 2001; Salafsky et al. 2008). Conservation, management, and restoration may be a decades-long process, but because of losses already suffered (especially given sea level rise), the effort is necessary (Warren et al. 2002).