Disasters & Land Management: May 2008 Archives
Corbicula fluminea. Often called the Asian clam, this small mollusk can clog intake pipes for cooling water.
Threat to Freshwater Ecosystems
Invasive species are one of the largest threats to our terrestrial, coastal and freshwater ecosystems, as well as being a major global concern.
Invasive species can affect aquatic ecosystems directly or by affecting the land in ways that harm aquatic ecosystems.
Threat to Biodiversity
Invasive species represent the second leading cause of species extinction and loss of biodiversity in aquatic environments worldwide. They also result in considerable economic effects through direct economic losses and management/control costs, while dramatically altering ecosystems supporting commercial and recreational activities.
Effects on aquatic ecosystems result in decreased native populations, modified water tables, changes in run-off dynamics and fire frequency, among other alterations. These ecological changes in turn impact many recreational and commercial activities dependent on aquatic ecosystems. Common sources of aquatic invasive species introduction include ballast water, aquaculture escapes, and accidental and/or intentional introductions, among others.
Ballast Water Carries Invasive Species
A major concern is the
introduction of invasive species through ship ballast water carrying
viable organisms from one waterbody to another. All mainland coasts of
the United States - East, West, Gulf, and Great Lakes, as well as the
coastal waters of Alaska, Hawaii, and the Pacific Islands - have felt
the effects of successful aquatic species invasions.
Over two-thirds of
recent non-native species introductions in marine and coastal areas are
likely due to ship-borne vectors, and ballast water transport and
discharge is the most universal and ubiquitous of these.
EPA is working in conjunction with our Federal and State partners to address this source of aquatic invasive species both domestically and internationally.
Solutions For LandscapersWe don't think about how our purchasing habits affect natural systems. But heavy global traffic on the oceans directly affects the invasive species on both water and land. In the water, we are finding clams, water plants are hitching a ride.
These same ships bring containers that contain seeds and eggs for snakes, spiders, even parrots that escape their confines and invade areas with little or no natural deterrents such as wildlife that eats them for food, or bacteria that control their growth and reproduction.
A simple solution is to buy local, native plants whenever possible. Even tools and equipment bought locally or in the US is a move to reduce ocean traffic to a manageable level.
When international trade is essential, it is important to work with reputable distribution systems that have safeguards in place and have stringent control systems that are explained to you...and measured.
