Many of the worlds big cities are on the coast or in estuaries. Although the ecological effects of urbanization have been widely studied, most research has concentrated on terrestrial habitats. Effects of urban change on marine habitats are largely ignored, even though urbanization causes very large changes to natural shorelines. Urbanization not only degrades and destroys habitats, but also adds many new and different types of habitat to the environment, the most common of which are seawalls. Although many intertidal and subtidal species live on them, seawalls do not appear to provide appropriate habitats for all species. Seawalls also degrade through time, producing intertidal piles of rubble, which superficially resemble intertidal boulder-fields. This talk examines assemblages of molluscs on seawalls, natural rocky shores, in natural boulder-fields and in those created by collapsed seawalls to identify changes that urbanization can bring to intertidal molluscs living in urbanized environments.
