Recently, however, with the International Maritime Organization review of harmful biocides in antifoulants, the pathway of invasive species introductions via ship fouling is being revisited. In fact, at the recent Corrosions Conference in Melbourne, Australia, all speakers at the session discussed hull fouling as a primary route of introduction of invasive species. Impacts of Harmful Invasive Species Marine invasive species can potentially constitute a serious ecological, economic and public health problem in any area they successfully colonize. Invasive species may out-compete or change habitats to such an extent that they make it impossible for native species to survive. Invading species are often predators, competitors or parasites.
Some invasive species can cause or carry disease.
Regardless of the direct or indirect nature of the effect, invasive species can significantly affect human health, devastate fishery and aquaculture resources, and severely impact human economy. These represent some of the better known and documented instances of successful invaders causing great harm at a considerable cost. About one fourth of bloom-causing species produce toxins that may harm or kill higher forms of life such as zooplankton, shellfish, fish, birds, marine mammals, and even humans, that feed either directly or indirectly on the algae. In addition, some bloom-causing species do not produce toxins but affect organisms indirectly through other means, such as decreasing light penetration, oxygen depletion, etc. It feeds on zooplankton, eggs and fish larvae.