Watersipora subtorquata is an abundant fouling organism. It is tolerant to copper based antifouling biocides so it facilitates the spread of other invasives by providing a non-toxic surface for other fouling species to settle. This trait is known from observation to occur in multiple species in the genus, including Watersipora arcuata (formerly, like W. subtorquata, referred to as W. cucullata) (Wisely 1958, Allen 1959)
A study in which a ship's hull was coated with three antifouling paints resulted in 64% of its surface covered with W. subtorquata within 16 weeks and 22 other species occurring exclusively on top of W. subtorquata colonies (Floerl et al. 2004).
In addition to its facultative interaction of spreading other non-indigenous species, W. subtorquata has its own competitive interactions with native bryozoans and community structures. It is the most common intertidal bryozoan in many areas of introduction. W. subtorquata along with Bugula neritina is considered the most common introduced species in harbors and estuaries in the context of hull fouling. In fact, its resistance to antifouling toxins that can collect in ports may give it an advantage over native biota. W. subtorquata has also demonstrated the ability to lie dormant in overly toxic conditions and recover as conditions improve. In Australia it is declared a medium priority pest (Floerl et al. 2004; Hayes et al. 2005; Mackie et al. 2006; Piola and Johnston, 2006).
No Impact information recorded for Watersipora subtorquata