Star barnacle

The star barnacle (Chthalamus stellatus) is a sessile crustacean belonging to the order Sessilia and the family Chthamalidae. While typically studied in marine biology, it is recognized as a significant pest in commercial maritime activities and aquaculture due to its tendency to colonize submerged man-made structures.

This species causes damage by settling on aquaculture cages, mesh screens, and water intake pipes. By forming thick, calcified encrustations, it restricts the flow of water necessary for oxygenation and nutrient distribution within fish and shellfish farming operations. Consequently, this leads to reduced animal health and lower overall production efficiency.

The biological cycle of the star barnacle involves a free-swimming larval stage, where individuals are transported by water currents before settling on a suitable surface. Once attached, they undergo metamorphosis into a permanent adult form. Their ability to colonize surfaces rapidly enables them to form dense populations in short periods, particularly in intertidal zones and submerged infrastructure.

The primary economic impact stems from the physical degradation of submerged equipment. The heavy weight of barnacle colonies, combined with their sharp, calcified edges, accelerates the wear of anti-corrosion materials and structural supports. Furthermore, the clogging of intake valves and conduits in industrial systems forces frequent and expensive manual cleaning operations.

Protection strategies focus on prevention rather than eradication. The most effective methods include the application of anti-fouling coatings that inhibit larval settlement. In industrial settings, periodic chlorination or the use of electrolytic systems is employed to maintain flow efficiency. Mechanical scraping remains a last resort due to the potential for causing further damage to the structural integrity of the equipment.