Commercial shipping is considered one of the most significant sources of aquatic invasive species (AIS) introductions. In fact, more than 80% of global trade moves by ship (OECD 2003, p.7). Both untreated ballast water releases and hull fouling are issues for commercial shipping that lead to AIS introductions. Although there have been some recent improvements to management practices, the industry’s steady growth suggests it could remain a significant source of AIS introductions.
Mandatory practices for commercial ships:
To help them stabilize as they load, unload, and transport goods around the world, today’s ships carry a tremendous amount of water. This is ballast. The problem is not the water itself, but the myriad of species this water contains. On one side of the ocean, ballast water and many marine species are pumped into the ship. When the ship reaches its destination, the water and surviving species are often dumped into a new environment as cargo replaces ballast. Although some mandatory ballast water management practices exist, it is still considered an important source of AIS. Prevention and education efforts for ballast water include:
- Ballast Water Page at MIT Sea Grant - Includes a fact sheet, information on treatment options, and more.
- Aquatic Nuisance Species Page by the U.S. Coast Guard - Includes information on current ballast water management practices.
- Massachusetts Aquatic Invasive Species Management Plan - Includes a section on commercial shipping and ballast water.
Despite the use of antifouling paints, boat hulls provide a surface for organisms with a sedentary life history stage to attach. Therefore, while some AIS may get transported on the inside of ships, others get transported on the outside.
If you have specific questions about commercial shipping and AIS, please contact us.