Hawaii's wetland restore water quality by removing toxic wastes, excess nutrient s, sediments, and other pollutants from runoff. Wetlands also prevent flooding b y storing water and then releasing it slowly downstream. Wetlands are also one o f the most important ecosystems. Birds breed, nest, feed and escape their predat ors in wetlands.
Wetlands also buffer shorelines against erosion and they absorb some greenhouse gases.
Prior to the settlement of the Europeans in Hawaii, it is hard to find just how much of the land was wetlands. Each of the ponds provided an average of 18 acres of wetland area throughout the State. Those figures showed that there were approximately 110,000 acres of w etlands in the State. By 1900 the amount of wetlands increased to about 114,000 acres because of increased expansion in wetland agriculture such as rice producti on. The present day number of 420 acres of wetland taro and watercress lands are the result of historical labor problems, the absence of ri ce production, the lack of demand for taro, and the competition for land for deve lopment purposes.