ABSTRACT

The marine coastal zone marks the transition between terrestrial and marine environments. This is a dynamic area that is constantly changing due to an interface of natural forces. While upland portions of the continents have changed slowly over geologic time (hundreds of millions of years), marine shorelines have been substantially in¤uenced by the movement of tectonic plates (i.e., continental drift) and Pleistocene glaciation. Drift has resulted in geological upheaval on the active continental margin due in part to sea¤oor subduction and produced mostly erosional processes in the passive margin or trailing edge of the continents over a few million years (Castro and Hubert 2007). More recently, sea level changes have had a great effect on low-lying shores (Figure 15.1). The shapes of coastlines we recognize today are the result of a 120-m rise in sea level that occurred less than 18,000 years before (Scotese 2004). In the past few decades, major storms have resulted in severe coastline alteration. Such storms can cause major physical changes, especially on beaches and ocean inlets. But there are natural processes that shape coastline habitats on a daily basis. What are these processes and how do organisms cope with them?