Smith College Study Calls for Better Handling of
Imported Live Marine Species
NORTHAMPTON, Mass.—Although most efforts to prevent marine invasions in the United States target organisms hitchhiking inside shipping vessels from foreign ports, the importation of live species for sale or science poses a threat that needs attention, says a new Smith College study.
Every time live marine species enter the country—for commercial use by seafood, bait and marine ornamentals businesses or for educational use at research universities and public aquariums—there is a risk of introducing exotic organisms into the environment, according to researchers who examined importation in the Northeast throughout a two-year period.
“The best strategy for minimizing damage from invasive species is to prevent their release into the environment, and prevention requires an understanding of where vulnerability exists,” said study co-author L. David Smith, associate professor of biological sciences at Smith College.
The danger of marine invasions is illustrated by the story of the thumbnail-sized zebra mussels thought to have hitchhiked to the Great Lakes during the early 1980s in the ballast water of vessels from Europe. Clusters of mussels, which have no native predator, have plugged pipes at power plants and city drinking systems and continue to cause problems for the native populations of infested waterways.
Published in the February issue of Conservation Biology, the Smith College study, which surveyed 160 operations in Massachusetts between 2000 and 2001, found that each importer had characteristics that could facilitate the invasion of an exotic species.
Risk factors were apparent from the moment the marine species entered the country because importers did not adequately identify species they brought in. Seafood, bait and marine ornamental businesses were among the importers that used common, rather than scientific, names to identify the organisms they received, a practice that severely limits the ability to screen for invasion potential, according to the researchers.
Although universities and public aquarium operations were better at identifying the organisms they imported, they, along with businesses, commonly reported seeing additional unidentified species or “hitchhikers” in their shipments. At least 50 percent of the importers surveyed reported seeing such hitchhikers.
The study also found that of those importers that held organisms in seawater, about half discharged untreated water directly into local waterways rather than through a municipal drainage line.
Enhanced standards for water discharge and identification need to be adopted, said lead author Shannon M. Weigle who completed the work as part of her master’s thesis at Northeastern University and the Massachusetts Bays National Estuary Program in Boston.
The National Invasive Species Act (NISA) has been a major funding source for programs aimed at preventing invasive species and calls for an improved reporting system for live imports, Weigle added. “Such a system is necessary in order to understand what species are being imported that may pose a threat to our environment.”
More research also needs to be done to determine the role consumer behavior has in handling exotic marine species since the deliberate or accidental release of organisms by consumers can also result invasions.
Funding for the study was provided by the National Oceanic and Atmospheric Administration’s Sea Grant Program. In addition to Smith and Weigle, other collaborators include James T. Carlton of the Maritime Studies Program at Williams College and Judith Pederson of the Sea Grant College Program at the Massachusetts Institute for Technology.
Smith College is consistently ranked among the nation’s foremost liberal arts colleges. Enrolling 2,800 students from every state and 60 other countries, Smith is the largest undergraduate women’s college in the country.
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