When we move to the coasts, the waters suffer Half of the world's people live near a sea coast. Most of our large cities are next to the ocean.
Coastal waters suffer from having so many people living and working nearby.
Wetlands have been paved or plowed under. Bay waters are polluted by sewage, oil, chemicals and agricultural fertilizer. We're pushing coastal habitat to the limit with development and industry. In the U.S. Pacific northwest, dams built for river control and hydroelectric power stop salmon when they try to swim upstream to spawn . In Thailand, Ecuador and many other tropical nations, coastal forests of mangroves once sheltered wild fish and shrimp, which local people caught to feed their families.