When
exotic plants and animals are brought to the U.S. from other countries or native
species are moved to inappropriate areas within the nation's borders, they can damage
native and endemic species. They change the native community structure and can create
economic challenges for the region.
In the U.S. alone, approximately 50,000 exotic species already are known to exist,
and this number is increasing constantly. The major environmental damages, losses,
and control measures for invasive species cost the nation an average of $138 billion
per year. Invasive species also threaten nearly half of the species currently protected
under the Endangered Species Act.
The introduction and spreading of invasive species are the result of several factors.
These include expanded global trade, the harvesting of exotic marine species to
satisfy the increasingly popular aquarium industry, and use of nonnative species
as agents in agriculture and pest control. Invasive species also are introduced
into the marine coastal environment when large ships exchange their ballast water.
CCEHBR scientists, with primary support from the
NCCOS/CCEHBR
Cooperative
Oxford Laboratory, are helping to Chesapeake Bay Program Non-indigenous
Species concerns. Issues addressed include problems associated with the introduction
of grass carp, Pacific sturgeon, Rapa whelks, and Asian oysters. Staff scientists
are actively engaged in evaluations of the proposed introduction of the Chinese
river oyster, Crassostrea ariakensis, into the Chesapeake Bay.
CCEHBR's
Marine Forensics research is also developing and applying DNA-based
assays to better ensure identification of species, invasives versus native.
Scientists also support work of the National Aquatic Nuisance Species Task Force (NANSTF).
They are currently involved with the Task Force's Green Crab Committee, which is
supporting state and industry efforts to monitor and control the spread of this
European species now into the west coast of the United States. Activities include
developing a management plan to help prevent or reduce the impact on the west coast
shellfish industry and other indigenous species.
CCEHBR's Estuaries
and Land Use team is also investigating the introduction of exotic Vibrio
pathogenic microbes from ballast water which may contaminate shellfish and impact
human health.
A related product developed by CCEHBR’s Coastal Ecology Program is the NOAA National Benthic Inventory (NBI) (http://nbi.noaa.gov), a quantitative database on distributions, abundances, and diversity of benthic species obtained from studies conducted nationwide by NCCOS and partnering institutions. The NBI includes features for tracking non-indigenous aquatic species (NAS) occurrences and is a participating database in the international NAS Database Network (NISbase). NISBase (http://www.nisbase.org), established by the U.S. Geological Survey and Smithsonian Environmental Research Center under the auspices of the NANSTF, is an online distributed network of databases providing information on NAS occurrences around the world. The integration of the NBI and NISBase databases enhance coastal managers' capabilities for detecting and monitoring occurrences of non-indigenous marine and estuarine species.