Understanding Biofouling and its Impact on Ship Performance

Biofouling, the unwelcome accumulation of microorganisms, plants, algae, or animals on wetted surfaces, can significantly hinder a ship’s performance, increase fuel consumption, and lead to higher operational costs.

What is Biofouling?

Biofouling refers to the accumulation of microorganisms, plants, algae, or small animals on wetted surfaces such as the hulls of ships. This natural process begins when microscopic organisms like bacteria and diatoms attach to a surface submerged in water. Over time, larger organisms such as barnacles, mussels, and seaweed can also adhere to the surface, forming complex and layered biofilms.

The process of biofouling can occur in both freshwater and marine environments, posing challenges across various industries including shipping, aquaculture, and offshore oil and gas. In the maritime industry, biofouling is particularly problematic as it can lead to increased fuel consumption, reduced speed, and higher maintenance costs.

How Biofouling Develops: A Timeline

The development of biofouling occurs in stages. Initially, within the first few hours of a surface being submerged, a thin layer of organic molecules forms. This layer, known as the conditioning film, provides a suitable environment for microorganisms to attach.

Within a few days, bacteria and diatoms colonize the surface, forming a microbial biofilm. As the biofilm matures, it becomes more complex and attracts larger organisms such as algae spores and small invertebrates. Over weeks and months, these organisms grow and multiply, leading to the formation of macrofouling communities consisting of seaweed, barnacles, and other larger marine organisms.

The timeline of biofouling can vary based on environmental factors such as water temperature, salinity, and nutrient availability. In warmer waters, biofouling tends to develop more rapidly.

The Impact of Biofouling on Ship Performance

Biofouling has significant implications for ship performance. The roughened surface caused by biofouling increases hydrodynamic drag, which in turn requires more energy to maintain the same speed. This increased resistance leads to higher fuel consumption and, consequently, higher operational costs.

Moreover, biofouling can cause mechanical issues. For instance, fouling organisms can clog seawater intake pipes and cooling systems, leading to potential overheating and damage to onboard equipment. Over time, the weight of accumulated biofouling can also affect a ship's stability and maneuverability.

In addition to the economic and operational impacts, biofouling can have environmental consequences. The transport of invasive species via fouled ship hulls can disrupt local ecosystems and biodiversity.

Current Methods to Combat Biofouling

Several methods are employed to combat biofouling. Traditional approaches include the use of antifouling paints and coatings that contain biocides to prevent the attachment of fouling organisms. These coatings can be effective but often require regular reapplication and can have harmful environmental effects.

Another method is dry-docking, where ships are taken out of the water for hull cleaning and maintenance. While effective, this process is time-consuming and costly.

Mechanical cleaning, such as using scrapers, brushes or high-pressure water jets, can also be employed to remove biofouling while the ship is in water. If mechanical cleaning is done when biofouling has progressed to the macrofouling stage, in-water mechanical cleaning will require a containment and disposal solution.

EverClean: A Proactive Solution for In-Water Cleaning

EverClean offers an innovative, proactive solution for in-water cleaning to combat biofouling. Unlike traditional methods, EverClean utilizes advanced robotic technology to perform regular, gentle cleaning of ship hulls to remove biofouling at the microfouling stage BEFORE it becomes a problem. Maintaining an always clean hull prevents the accumulation of fouling organisms before they can form complex and resistant biofilms.

The EverClean system is designed to be environmentally friendly, reducing the need for harmful chemical coatings and minimizing the risk of spreading invasive species. By maintaining a clean hull, EverClean not only improves fuel efficiency and reduces operational costs but also extends the lifespan of antifouling coatings.

Overall, EverClean represents a sustainable and cost-effective solution for managing biofouling, ensuring optimal ship performance and contributing to the protection of marine environments.

Additional Resources:

• Video: How EverClean Works