The impact and management of exotic dune grasses near the mouth of the Murray River South Australia

Abstract

Exotic dune grasses pose a threat to the natural character of land in the vicinity of the mouth of the Murray River in South Australia. Coastal management responsibilities for the mouth are complex, with juxtaposed and in some places overlapping jurisdictions involving three tiers of government. This article examines the threat posed by invasive dune grasses in the context of the existing coastal management regime for the area. The history of pyp grass (Ehrharta villosa) and sea-wheat grass (Thinopyrum junceiforme) dispersal and invasion indicates that an effective management approach should include (1) regular reconnaissance, early recognition and eradication of potential problem species during the establishment phase of their invasion history; (2) ongoing monitoring of rates of invasion of established species; (3) understanding processes of invasion; (4) developing strategies for containment or eradication; and (5) recognizing and protecting core conservation areas. Each of these elements will require education of stakeholders given the current low level of understanding of the natural dynamics of coastal dune systems and the nature of the risks posed by invasive species.