Potential biocontrol agents for biofouling on artificial structures

Abstract

The accumulation of biofouling on coastal structures can lead to operational impacts and may harbour problematic organisms, including non-indigenous species. Benthic predators and grazers that can supress biofouling, and which are able to be artificially enhanced, have potential value as augmentative biocontrol agents. The ability of New Zealand native invertebrates to control biofouling on marina pontoons and wharf piles was tested. Caging experiments evaluated the ability of biocontrol to mitigate established biofouling, and to prevent fouling accumulation on defouled surfaces. On pontoons, the gastropods Haliotis iris and Cookia sulcata reduced established biofouling cover by >55% and largely prevented the accumulation of new biofouling over three months. On wharf piles C. sulcata removed 65% of biofouling biomass and reduced its cover by 73%. C. sulcata also had better retention and survival rates than other agents. Augmentative biocontrol has the potential to be an effective method to mitigate biofouling on marine structures.

Keywords:

• biological control
• natural enemies
• non-indigenous species
• fouling
• pest management

Acknowledgements

The authors thank Nelson Marina and Port Marlborough for logistic support. This research was funded by the National Institute of Water and Atmospheric Research (NIWA) under Coasts and Oceans Research Programme 4 – Marine Biosecurity (2013/2014 SCI).