A portable thermal system for reactive treatment of biofouled internal pipework on recreational vessels

Biofouled commercial and recreational vessels are primary vectors for the introduction and spread of marine non-indigenous species (NIS). This study designed and assessed a portable system to reactively treat biofouling in the internal pipework of recreational vessels – a high-risk ‘niche area’ for NIS that is difficult to access and manage. A novel thermal treatment apparatus was optimised in a series of laboratory experiments performed using scale models of vessel pipework configurations. Treatment effectiveness was validated using the Pacific oyster Magallana gigas, a marine NIS with known resilience to heat. In subsequent field validations on actual recreational vessels, treatment was successfully delivered to high-risk portions of pipework when an effective seal between delivery unit and targeted pipework was achieved and ambient heat loss was minimised. In addition to demonstrating the feasibility of in-water treatment of vessel pipework, the study highlights the importance of robust optimisation and validation of any treatment system intended for biosecurity purposes. [Display omitted] •Recreational vessel internal pipework biofouling can pose biosecurity risk.•Portable thermal system for reactively treating pipework biofouling was developed.•Laboratory experiments showed thermal treatment to be effective and rapid.•Field refinement to operationalise system to compliment other treatment approaches