Northeast Marine Introduced Species (NEMIS) - Print Edition

Pathways and Prevention : Shipping

Shipping is often considered the major pathway for marine introductions. Commercial shipping (both international and within the country), recreational boating, cruise ships, and small commercial vessels (such as fishing, barges, and ferry boats), can all serve as pathways for the movement and introduction of species. The most common shipping-related pathways for introduction of non-native marine species include via ballast water, hull fouling, sea chests, other seawater discharges, and other areas of ships where plants or animals can attach.

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Ballast Water Hull Fouling:
Hull Fouling:
Sea Chests, Live Wells and Other Shipping Vectors
Hull Fouling : Commercial

What is the Problem?

Often overlooked are the fouling organisms that attach to hard surfaces of vessels and boats. Although most well-maintained boats use an antifouling paint to retard growth of fouling organisms, paint chips off and some areas may no be treated. Both commercial and recreational vessels are likely to carry some fouling organisms from location to location. This section focuses on commercial vessels that are engaged in both foreign and coastwise traffic.

What are we concerned about?

When large vessels are removed for maintenance and treatment of hulls to retard fouling, they are placed on cradles that prevent treatment under the area of the cradle. Other areas on the vessels may be missed with antifouling paints, and in older vessels chipping and rust formations may expose these areas to fouling organisms. This may be a much greater source of new introductions than previously considered.

Commercial vessel owners should inspect the hulls of their vessels regularly and safely remove all fouling organisms. In addition to divers, new autonomous underwater vehicles can perform inspections to facilitate clean up efforts.

What are the solutions?

Frequent inspections of commercial ship hulls, not only is a best management practice for minimizing introductions of fouling organisms, but also reduces drag on the vessel that increases the use of fossil fuels.


Ballast Water Fact Sheets
International Convention on the Control of Harmful Anti-fouling Systems on Ships
Anti Fouling Paint
Nontoxic, Anti-Fouling Paint Protects Ships, Ocean Life
NanoSafeguard 2-K Marine Sealant
The Ban on Toxic Marine Anti-Fouling Paints


Anti-Corrosion and Anti-Fouling Paints for Ships' Hulls, Anti-Corrosion Methods and Materials Journal, 1957, Vol. 4 (2), pp. 60-61.

Zebra Mussel Research Technical Notes

Zebra Mussel Research Technical Notes