Ships are used as a means to transfer goods and materials globally and routinely travel through diverse environments including estuarine, coastal and oceanic regions. Given the volume and scope of global shipping, ships are one of the leading vectors for the transport of aquatic invasive species world-wide. The use of ships to transport goods is not a new practice but has occurred for centuries. However, changes in world-wide trade and shipping patterns, the growing number of ships and different ship types, and the increased speed of global transport are all key factors which may contribute to higher invasion rates.
There are two mechanisms by which ships act as vectors for transferring aquatic invasive species:
Over the last 10 years, MIRL has conducted extensive research investigating the role of ballast water transport as an invasion mechanism, focusing on the following research questions:
• Survivorship, composition and density of organisms being transported in ballast and how this is impacted by vessel type, source water, duration of voyage, and other environmental factors.
• Quantitative studies on ballast water discharge in Chesapeake Bay, San Francisco Bay and Port Valdez, AK.
• Determining biological and physical parameters for certain species and how this relates to their ability to invade a particular geographic region.
• Investigating the role of ballast water exchange as a management option and evaluating its effectiveness on a variety of vessel types originating from both high and low salinity coastal source regions.