Land-Coastal Ocean Interactions in the Tropics and Subtropics: Hawaii as An Example.

摘要

The culture, subsistence, and welfare of tropical and subtropical Pacific Island Nation people are all in some way tied to the interactions between the land and the adjacent and surrounding coastal waters. Land use plays an important role in the relative chemical species distribution and concentrations of particulate and dissolved nutrients that reach coastal waters by riverine, groundwater, and atmosphere. Some key human activities on land that affect coastal waters through land-sea connections and interactions are: (1) the application of nitrogenous and phosphorus-bearing fertilizers and biocides to the landscape and subsequent leaching of significant proportions of these materials into water courses, (2) the release of sewage into aquatic systems, including directly into coastal ocean waters, (3) the diversion of water flows through channelized structures and dams resulting in changes in retention times of water, nutrients and sediments and also in riparian communities on land and hence changes in water, nutrient and suspended sediment fluxes to the coastal ocean, (4) deforestation and/or conversion of land type from, for example, agricultural use to urban housing, (5) the fallout of nitrogen from the atmosphere derived from combustion sources on land and its ultimate transport into aquatic systems, (6) CO2 emissions from fossil fuel and land-use activities (e.g., deforestation) and absorption of some of this CO2 by coastal and open ocean waters, and (7) atmospheric nitrogen emissions from combustion sources on land that ultimately fall directly on the ocean surface, and especially that of the coastal ocean.