Desiccation as a mitigation tool to manage biofouling risks: trials on temperate taxa to elucidate factors influencing mortality rates

Abstract

The desiccation tolerance of biofouling taxa (adults and early life-stages) was determined under both controlled and ‘realistic’ field conditions. Adults of the ascidian Ciona spp. died within 24 h. Mortality in the adult blue mussel Mytilus galloprovincialis occurred within 11 d under controlled conditions, compared with 7 d when held outside. The Pacific oyster Crassostrea gigas was the most desiccation-tolerant taxon tested (up to 34 d under controlled conditions). Biofouling orientated to direct sunlight showed faster mortality rates for all the taxa tested. Mortality in Mytilus juveniles took up to 24 h, compared with 8 h for Ciona, with greater survival at the higher temperature (18.5°C) and humidity (~95% RH) treatment combination. This study demonstrated that desiccation can be an effective mitigation method for a broad range of fouling taxa, especially their early life-stages. Further work is necessary to assess risks from other high-risk species such as algae and cyst forming species.

Keywords:

• Biofouling
• desiccation
• invasive species management
• anthropogenic spread
• treatment tools

Acknowledgements

The authors are grateful to Rosemary Brook (University of Birmingham) and Tim Dodgshun (Cawthron Institute) for their assistance with various aspects of the experiments presented.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was funded by the National Institute of Water and Atmospheric Research (NIWA) under Coasts and Oceans Research Programme 6 – Marine Biosecurity [2014-15 SCI].