Marine Fouling is threat for a multitude of technical devices in freshwater and a dominant problem in marine waters. Macrofouling can enhance the weight and the friction resistance to such a degree that a ship cannot speed ahead. Fouling at intakes of open cooling systems may reduce the amount of sucked to such a degree that the plant has to be shut down. Nets in mariculture can be fouled and clogged effectively thus leading to asphyxation of of fish oyster or abablones. Sludges may be fouled by sponges or oysters leading to malfunction or destruction of the anticorrosive coatings.
Since decades antifoulings systems are based on leaching biocides which shall kill the fouling organisms and impede the settlement of spores and larvae. But the use of biocidal products has been and is still associated with numerous problems:
not only target organisms are killed
biocidal products should achieve a surface free of fouling for 2 – 5 or even 12 years, but shall show easy degradation and no accumulation
in aquatic organisms, mariculture products or marine food no residues are wanted
These contradictions initiated 30 years ago the first development of biocide-free antifouling systems which are reflected in a variety of product types. Basically, the following are available on the market:
The following systems are in the developmental stage or just entering the market:
The EU Biocidal Products Directive and regulation for sea food production and import e. g. in Japan and Australia induced an increasing interest in the development of biocide-free antifouling systems. They are even attractive as the putting on the market does not deserve a long and expensive approval. In parallel, after the ban of selected biocides in the Netherlands, Sweden and UK biocide-free systems entered the market. As shown by several investigations biocide-free systems deserve a thorough examination of their efficacy and environmental compatibility.
For more than 25 years LimnoMar has been working on the development of effective antifouling systems causing no threat to humans and wildlife. Up to now, no general solution has been found. Some customer adapted solutions for concrete applications are at hand and have carefully selected. LimnoMar offers along with the investigation of innovative systems consultancy for customers focussing the most advanced systems with own experience.