Researchers in Hong Kong may have found a solution to the age-old problem of keeping a ship’s hull free from marine pest organisms, but without polluting the world’s oceans.
The development of biofouling communities on man-made structures is a significant problem for all marine industries. For years, ship owners have coated the hulls of their vessels with highly toxic antifouling paints to prevent marine growth and ensure their vessels travel faster and more efficiently.

Ship’s hull with modern antifouling paint, a nest of tubeworms, and tubeworms in detail

Production of the most effective paint, based on the biocide organotin, was banned in 2003. Remaining methods used to control biofouling are costly and environmentally hazardous.
At The Hong Kong University of Science and Technology (HKUST), Prof Peiyuan Qian has been leading a team of investigators from other Hong Kong institutions to explore the natural antifouling substances produced by marine organisms such as sponges and marine bacteria.
Centred at HKUST’s Coastal Marine Laboratory, the region’s largest collection of marine bacteria has been established as part of the research. Said Prof Qian: “The collection has proved to be a goldmine for the discovery of novel bioactive compounds for antifouling, agents to help in the biodegradation of marine pollutants, and as a source of marine biotoxins.”
Altogether, 10 non-toxic compounds produced by marine microbes as natural fouling inhibitors have been identified.
“They may lead to very useful non-polluting applications,” said Prof Qian. Among discoveries in the research was that highly potent antifouling and antibiotic compounds are produced by the bacteria and fungi living on sponges and seaweeds.
Said Prof Qian: “The products prevent larval settlement of fouling organisms through a non-toxic mode so do not kill organisms but inhibit their settlement. They are environmentally friendly.”
He added: “With modern fermentation technology, we can produce these products cost-effectively in large quantities. Unlike the production of most bioactive compounds, we do not need to harvest the marine organisms from the natural environment.”
Applications for patents have been made in the US and China, and contacts have been made with shipyards and paint companies to explore commercial development and use. The collection of marine microbes includes 16 novel bacterial species and four genera never before identified. Samples come from the South China Sea, Yellow Sea, Caribbean, Mediterranean, North Sea, Northwest Pacific Ocean, the deep sea and Antarctic region.
“With the banning of some antifouling paints, the marine coating industry needs to find a solution right away,” said Prof Qian.
The project has involved investigators from The Chinese University of Hong Kong, The University of Hong Kong, and City University of Hong Kong as well as HKUST.

Principal Investigator
Prof Peiyuan Qian : boqianpy@ust.hk