In-water vessel hull treatment may be an option to remove (or kill) biofouling, optimise the performance of vessels, improve the operation of some anti-fouling coatings (AFC), and minimise biosecurity risks. However, some treatments may inadvertently release live aquatic pests, physically damage or shorten the service life of AFCs, and may release biocide that can contaminate the aquatic environment.
The Department of Fisheries has developed State-specific in-water treatment guidelines to be used in conjunction with the national Anti-fouling and in-water Cleaning Guidelines (DAFF 2013). The State guidelines have been developed to establish when and where vessels may be treated in-water in WA.
‘Clean before you leave’
The Department promotes the ‘clean before you leave’ approach to vessel hygiene as the best way to prevent the entry of aquatic pests into WA waters. This best-practice approach requires vessel manages to appropriately manage ballast water and hull biofouling before entering WA.
Prevention is the best method
From a biosecurity perspective, in-water cleaning is not a good option for the management of vessels and movable structures. Prevention is the best method and when dealing with heavy macrofouling, the most effective option is to remove vessels and movable structures from the water for cleaning. However, it is recognised that to keep vessels operating at their maximum efficiency, regular removal of low levels of biofouling is desirable, and this may include in-water treatment where appropriate.
The Department may also support in-water treatment of vessels when there is a biosecurity emergency, in accordance with Departmental direction.
Development of in-water treatment systems
The Department encourages the development of in-water vessel treatment systems however, they must meet certain requirements which are detailed in the State guidelines to be endorsed by the Department.
Applying for in-water treatment in WA waters
The Department will consider supporting in-water treatment by an endorsed system in WA waters. Those applying to clean should follow both the National and State guidelines.
The simplified process for applying to in-water clean a vessel in WA is:
Assess whether the vessel is free of aquatic pests by risk assessment or inspection
Assess whether cleaning is possible using the National guidelines’ decision tool
Assess whether cleaning is possible using the State guidelines’ decision tool
Apply to the Department for endorsement
If endorsed, treat within 7 days, and submit results to the Department.
The full WA in-water treatment guidelines can be downloaded here Guidelines for the in-water treatment of vessels in Western Australia waters