Better biosecurity: spread-prevention of the invasive Asian clam, Corbicula fluminea (Müller, 1774)

摘要

Aquatic invasive species (AIS) negatively impact freshwater ecosystems on aglobal scale. As management options for control and eradication of established AISpopulations are often complex, costly and resource-intensive, spread-preventionprotocols are considered essential. The Asian clam, Corbicula fluminea (Müller,1774), is considered a high-impact successful invader that can adversely alterfreshwater habitats, community dynamics and ecosystem function. Accordingly, weexamine the efficacy of a range of biosecurity techniques, including recommended(aquatic disinfectants, bleach and salt solutions) and more novel (hot water anddirect steam) approaches, to induce adult C. fluminea mortality. In separateexperiments, C. fluminea were submerged at 12 °C for up to 80 minutes in: 1) 2%and 4% solutions of Virasure? Aquatic and Virkon? Aquatic; 2) warm (30 °C) 2%and 4% solutions of these disinfectants; and 3) 10% and 20% bleach solutions.Furthermore, specimens were exposed to: 4) 30% and 70% salt solutions (NaCl) forup to 72 hrs; 5) hot water (35, 40 and 45 °C) for up to 20 minutes; and 6), directsteam exposure for up to 10 minutes. Adult C. fluminea were found to be largelyresistant to aquatic disinfectants, bleach and salt solutions, with ≤ 58% mortalityachieved at the maximum exposure times. However, immersion in hot water (≥ 45 °C)and direct steam exposure for five minutes and 30 seconds, respectively, rapidlycaused mortality. Accordingly, simple biosecurity protocols that cause thermalshock appear highly effective. We discuss the need for further examination ofbiosecurity protocols across all life stages of current, emerging and potential AIS,and provide guidance for improving biosecurity practices.