Biofouling is unwanted accumulation of marine organisms on both natural and artificial substrates, including aquaculture stock and products (such as biofouling of mussel or oyster shells), artificial infrastructure (including vessel hulls, rudders, propellers and other hull appendages), internal seawater systems (including sea chests and pipe work) or any submerged equipment used in the industry.
Biofouling is divided into microfouling — biofilm formation and bacterial adhesion — and macrofouling — attachment of larger organisms. Due to the distinct chemistry and biology that determine what prevents them from settling, organisms are also classified as hard- or soft-fouling types.
The first stage from which the great fouling begins is biofilm.
Biofouling initial process: (left) Coating of submerged “substratum” with polymers. (moving right) Bacterial attachment and extracellular polymeric substance (EPS) matrix formation.
Non-calcareous (soft) fouling organisms include
- biofilm “slime”.
Calcareous (hard) fouling organisms
- encrusting bryozoans,
- tube worms,
- zebra mussels and many other.
Together, these organisms form a fouling community.
The variety among biofouling organisms is highly diverse and extends far beyond the attachment of barnacles and seaweeds. According to some estimates, over 1,700 species comprising over 4,000 organisms are responsible for biofouling.
Here are images of nine of them:
…and more than 6000 types and kinds more
- design and construction, particularly the number, location and design of niche areas (e.g. sea chests, bow thrusters, hull appendages, and protrusions, etc.);
- specific operating profiles, including parameters such as operating speeds, a ratio of time underway compared with time alongside, moored or at anchor, and where the ship is located when not in use (e.g. open anchorage or estuarine port);
- places visited and trading routes (e.g. depending on water temperature and salinity, abundance of fouling organisms, etc.);
- maintenance history, including the type, age, and condition of any anti-fouling coating, installation and operation of anti-fouling systems and dry-docking/slipping and hull cleaning practices.
Governments and industry spend more than US$5.7 billion annually to prevent and control marine biofouling. Biofouling occurs everywhere but is most significant economically to the shipping industries, since fouling on a ship’s hull significantly increases drag, reducing the overall hydrodynamic performance of the vessel, and increases the fuel consumption.
We divided the level of biofouling on the category
|Description of condition||Fouling rating|
Hydraulically smooth surface
FOULING RATE 0 (FR-0)
Deteriorated coating or light slime
FOULING RATE 20 (FR-20)
FOULING RATE 30 (FR-30)
Small calcareous fouling or weed
FOULING RATE 60 (FR-60)
Medium calcareous fouling
FOULING RATE 80 (FR-80)
Heavy calcareous fouling
FOULING RATE 100 (FR-100)
What biofouling looks like
At the moment, there is no one hundred percent way to get rid of biofouling. Even the most advanced developments in the field of anti-fouling coatings do not significantly slow down the process, but do not stop it completely.
We absolutely agree with you that it looks terrible. Many people think that you need a lot of years that would have grown on the body so much biofouling. But they are all very surprised when they find out that this is possible in just 12 months. And if we talk about heavy biofilm, this process needs only a few months. A simple biofilm, which is the initial stage of the biofouling process, appears on the hull of your vessel within a few days. The less time passes between cleaning, the larger organisms settle on the body. And the more difficult it will be to remove them and the more damage they will cause to the coating of the body and your protection from biofouling.