There are three principal transport pathways (rivers, atmosphere, ground/sediment water) and two directions (to and from the sea) to consider. Traditionally, the seaward riverine movement of contaminants has been seen as the major transport route. Indeed, for a number of components and for distinct marine locations not only is the coastal zone a required pathway for contaminant transfer, but estuaries in particular are uni-directional routes for dissolved and suspended particulate matter passing from the continent to the marine system. For others, and for locations in the coastal waters further from land, the atmosphere may actually be the principal route. Nevertheless, in both cases research into contaminant flow to the coast has commented on potential anthropogenic impact. The third transport route, ground and sediment water from below, has considered both anthropogenic and naturally occurring contaminants. Interest has been driven by a focus upon anthropogenic origins, whilst in release from sediments there has also been interest in natural contaminant sources.
Particulate
A very small solid suspended in air or water which can vary widely in size, shape, density, and electrical charge.
See Glossary for a complete list of all terms. |
The flow in the opposite direction, of contaminants from coastal waters to the atmosphere, and on occasions to land, is highly significant in some cases. Very often concern is with naturally occurring substances, the release of which may or may not be subject to anthropogenic influence. In all cases, land-to-sea or sea-to-land, the significance of the topic lies in the distinct combinations of factors which occur, putting an emphasis on the very coastal nature of contaminant exchanges. | 
