| Abstract: | Field observations on rocky shores in New South Wales suggested a link between pools or wet crevices, predatory whelks foraging from them, and areas around the crevices that were mostly bare of prey (‘haloes’). Whelks were most common in and around crevices but ventured out to feed. Previous work had shown that foraging excursions were cyclical over time. The community of prey also changed with distance from crevices, most types of prey being more abundant further away. A field experiment showed this pattern to be at least partly due to the crevice-bound foraging of the whelks. Experimental removal of whelks over 2 years at several sites caused the gradients in the abundance of prey with distance from crevices to disappear, whilst these patterns persisted and even grew more intense in adjacent control areas. This combination of biotic and physical processes (predation, desiccation, foraging behaviour) is discussed as an important influence on spatial patterning in this and other communities. |
