The Apparent Eradication of a Locally Established Introduced Marine Pest

Abstract

Once a marine invader has become established, its subsequent control has rarely been attempted. We report the first apparently successful eradication of a locally well-established introduced marine pest. A previously unknown species of sabellid polychaete (now described as Terebrasabella heterouncinata arrived as an epizoic contaminant on South African abalone imported to California for commercial aquaculture research. In 1996, we detected an established sabellid population at an intertidal site near Cayucos, California (35 °45'N, 120 °95'W). To mitigate the impact of this introduced marine pest at this site, and prevent or slow its geographic spread, we proposed an eradication program based on the epidemiological theory of the threshold of transmission. Specifically, we removed 1.6 million of the most highly susceptible and preferred host in the intertidal area; the black turban snail, Tegula funebralis. A screen was also installed at the associated abalone mariculture facility to eliminate release of additional infested material (the source of the established sabellid population) and all such material was removed from the intertidal area. Using transect surveys and mark and recapture studies, we monitored the success of the eradication effort. Transmission of the pest can no longer be detected. Hence, the established sabellid population has apparently been eradicated. This discovery demonstrates that some alien marine pests can be eradicated and supports development of new proactive approaches to the management of other exotic marine pests.