Control strategies for established populations of invasive alien species can be costly and complex endeavours, which are frequently unsuccessful. Therefore, rapid-reaction techniques that are capable of maximising efficacy whilst minimising environmental damage are urgently required. The Asian clam (Corbicula fluminea Müller, 1774), and the zebra mussel (Dreissena polymorpha Pallas, 1771), are invaders capable of adversely affecting the functioning and biodiversity of freshwater ecosystems. Despite efforts to implement substantial population-control measures, both species continue to spread and persist within freshwater environments. As bivalve beds often become exposed during low-water conditions, this study examined the efficacy of steam-spray (≥100 °C, 350 kPa) and open-flame burn treatments (~1000 °C) to kill exposed individuals. Direct steam exposure lasting for 5 min caused 100% mortality of C. fluminea buried at a depth of 3 cm. Further, combined rake and thermal shock treatments, whereby the substrate is disturbed between each application of either a steam or open flame, caused 100% mortality of C. fluminea specimens residing within a 4-cm deep substrate patch, following three consecutive treatment applications. However, deeper 8-cm patches and water-saturated substrate reduced maximum bivalve species mortality rates to 77% and 70%, respectively. Finally, 100% of D. polymorpha specimens were killed following exposure to steam and open-flame treatments lasting for 30 s and 5 s, respectively. Overall, our results confirm the efficacy of thermal shock treatments as a potential tool for substantial control of low-water-exposed bivalves. Although promising, our results require validation through upscaling to field application, with consideration of other substrate types, increased substrate depth, greater bivalve densities, non-target and long-term treatment effects.
Bibliographical noteFunding Information:
The authors gratefully acknowledge support from the Irish Environmental Protection Agency project “Prevention, control and eradication of invasive alien species” (2015-NC-MS-4). JTAD also acknowledges funding received from the Natural Environment Research Council. RNC acknowledges funding from the Alexander von Humboldt Foundation. We particularly thank Inland Fisheries Ireland for specimen collection. We also thank Dr. Lawrence Eagling, Dr. Patrick Joyce, Dr. Nick Horne and Simon Exley for their helpful contributions.
© 2020, The Author(s).
Copyright 2020 Elsevier B.V., All rights reserved.
- Invasive alien species
- Open-flame heat torch
- Population control
- Thermal shock
ASJC Scopus subject areas
- Global and Planetary Change