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.

What is the Problem?

Areas that are often not treated but the source of living, reproducing organisms include Sea Chests or areas where water is held prior to use for "priming pumps." A 1-cm mesh often covers the sea chest opening allowing constant exchange with the open waters. Over 150 organisms have been found in 42 sea chests, including crabs that were carrying eggs (Coutts and Dodgshun 2007). These sea chests are potential areas of distribution for invaders.

What are we concerned about?

Over 150 organisms have been found in 42 sea chests, including crabs that were carrying eggs (Coutts and Dodgshun 2007). These sea chests are potential areas of distribution for invaders.

Schematic diagram of a vessel's sea-chest system. From Coutts ADM and Dodgshun TJ, 2007, The nature and extent of organisms in vessel sea-chests: A protected mechanism for marine bioinvasions. Marine Pollution Bulletin 54: 875-886.

A Vessel sea chest and a plate with slits that covers the opening, which are cleaned periodically. [ more info ]
Photo: California Sea Grant College Program

What are the solutions?

Cleaning out sea chests, live wells, and other areas of the vessels that contain and retain water for some period of time are potential sources of potential invaders.

Links

Information on Sea Chests

Publications

Coutts ADM and Dodgshun TJ 2007. The nature and extent of organisms in vessel sea-chests: A protected mechanism for marine bioinvasions. Marine Pollution Bulletin 54: 875-886.

Coutts ADM and Dodgshun GJ 2003. Ships' Sea Chests: Abstract: The Overlooked Mechanism for Species Transfers? Proceedings of the 2003 MBIC, page 31