Subsea Industries has announced that it believes that the entry into force of the Ballast Water Convention will not prevent the transfer of invasive aquatic species (IAS) unless there is mandatory legislation in place to prevent biofouling on ships’ hulls.
Hull Biofouling - More Damaging than Ballast Water Transfer
| Studies have concluded that hull fouling
is more environmentally damaging than IAS relocated
through ballasting operations
Commenting on a presentation delivered at the World Ocean Council’s Sustainable Ocean Summit in December, in which IMO Marine Environmental Division’s Technical Officer Dr Theofanis Karyannis has revealed that hull biofouling could be more damaging than ballast water transfer. Subsea Industries’ Chairman Boud Van Rompay said: “The transfer of IAS in ballast water has been addressed with the ratification of the BWM Convention, but currently there is no legislation to prevent the transfer of IAS on ships’ hulls though fouling, only guidelines
The Biofouling Issue
- While there is ongoing evaluation of the Biofouling Guidelines set out in MEPC.1/Circ.811, there has been little support from IMO Member States for a new mandatory instrument to reduce the impact of bioufouling
- Aside from the guidelines, the issue of biofouling is thought not to be on the agenda of the MEPC or any other IMO body.
- There has been a number of studies comparing the transfer of IAS through ballast with that transferred by hull fouling, with some studies concluding that hull fouling is more environmentally damaging than IAS relocated through ballasting operations.
In his paper Building Partnerships to Address the Global Impacts from Aquatic Biofouling, Dr Karyannis revealed a number of areas where hull biofouling was the primary factor for IAS.
| Unlike biocidal coatings, the in-water cleaning of
hard inert coatings is permitted in most of the
world’s ports and harbors
“The IAS threat is increasing especially because antifouling systems in use since the ban on tributyltin (TBT) are less effective in eliminating hull fouling,
” said Van Rompay. “Some species have developed a resistance to copper biocides and are thriving in ports and harbors where copper and organotin residues are high
Preventing Spread of IAS with Non-toxic Hard-type Coating
According to Van Rompay, frequent in-water hull cleaning of a hard, inert coating is the key to preventing IAS translocation, since the removal of micro- and macro-fouling acquired locally poses no risk whatsoever.
However, there is a dichotomy in that the in-water cleaning of biocidal antifouling systems
is banned in many ports and harbors around the world as the chemicals in these coatings pose an environmental hazard of their own. Cleaning macro-fouling from these hulls also damages the coatings.
“The only real answer to preventing the spread of IAS is by ensuring that ships sail with a clean hull from their point of origin. Only a non-toxic hard-type coating and regular in-water cleaning can achieve this. Indeed, many ports and harbors permit the in-water cleaning of this type of coating system. Effective biofouling control is also the most efficient way of reducing fuel consumption and greenhouse gas emissions
,” Van Rompay said.
About Subsea Industries
Subsea Cleaning Systems, later Subsea Industries nv, was founded in 1983 specifically to take care of the design, development and marketing of what has become an evolving line of underwater hull and propeller cleaning equipment and later, the line of hard hull coating systems.
Source: Subsea Industries