**4. Threats to seagrass habitats in Indonesia and the world**

The main problems affecting seagrass ecosystems throughout the world are due to continuous dredging and stockpiling activities and water pollution including salt waste disposal from desalinization activities and oil production facilities, the inclusion of pollution around industrial facilities, and waste hot water from a power plant. Until now the world's seagrass damage has reached 58%, and since 1980 every 30 minutes, the world lost seagrass the size of a soccer field [4, 5]. Furthermore, the distribution of global seagrasses has been lost by about 29% since the nineteenth century [6]. The main cause of the loss of seagrass globally is a decrease in water brightness, both due to increased turbidity of the water and increased input of nutrients to the waters. In temperate regions, the loss of seagrass is caused by the conversion of coastal areas into industrial estates, settlements, and flooding from the mainland. Meanwhile, the main cause of the loss of seagrass beds in the tropics is an increase in sediment input into coastal waters due to logging on land and logging of coastal mangroves that coincide with the direct influence of fishery cultivation activities.

The widespread decline of seagrass beds in Indonesia can be caused by natural factors and the results of human activities, especially in coastal environments. Natural factors include strong waves and currents, storms, earthquakes, and tsunamis. Meanwhile, human activities that contribute to the decline of seagrass areas are coastal reclamation, sand dredging and mining, and pollution. For example, seagrass cover on Pari Island (Thousand Islands) has been reduced by 25% from 1999 to 2004 allegedly due to rampant development on the island [3].
