 | James Anderson
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Researcher: Introduction of non-native oysters could impact entire East CoastAt a time when exotic species are being blamed for significant population declines of native species around the world, some government officials and the oyster industry in the Chesapeake Bay area are clamoring to introduce the Asian Suminoe oyster (Crassotrea ariakensis) to boost the economy.
But URI Professor James Anderson, who recently co-chaired a National Research Council committee examining the proposal, cautions that a rapid introduction of the non-native oysters could cause considerable problems up and down the East Coast and ultimately have a negative impact on the region’s economy.
“It’s very difficult to contain most introduced species once they’re in the environment,” Anderson said, citing the examples of zebra mussels and kudzu, which have spread rapidly and done irreparable harm to local species. “We don’t know much about the biology of the Suminoe oyster and how it will compete with native oysters. It might undermine the recovery of the native species.”
Anderson’s committee was less concerned with the impact of introducing the oyster to the Bay than they were with potential “hitchhikers” - diseases, crabs, sponges or other organisms that might be relocated to the Bay along with the transplanted oysters.
Commercial harvest of oysters in the Chesapeake Bay is now less than one percent of what it was a century ago, due in large part to fishing pressures and habitat degradation caused by agricultural, industrial and residential pollution. In recent decades, however, the diseases MSX and Dermo have been identified as the primary reasons for further decline. The result has been an economic disaster for many communities tied to the oyster industry and has contributed to a degradation of the Bay’s water quality, since oysters filter the water of microscopic algae.
The committee was charged with analyzing the ecological and socio-economic risks associated with three management options: not introducing non-native oysters at all; introducing a limited number of sterile non-native oysters; or introducing large numbers of reproductive Asian oysters. The committee concluded that the best option was a controlled aquaculture of the sterile oysters so their impact on the Bay’s ecosystem could be better evaluated before a full-scale introduction was done.
“Decisions being made in the Chesapeake Bay could potentially impact the whole East Coast from the Carolinas to New England,” said the URI professor. “While it’s not uncommon for non-native oysters to be introduced elsewhere - the oyster industry in France and on the U.S. West Coast is primarily based on non-native oysters - every reintroduction poses a considerable risk.”
In addition to choosing one of the proposed options, Anderson’s committee strongly recommended that any introduction of non-native species follow the appropriate international protocol, which includes quarantining the oysters to test for pathogens. The group also concluded that the current regulatory framework is inadequate to address multi-state species introductions like the one proposed.
“If Virginia says it wants to introduce the oysters and Maryland says it doesn’t, the oysters from Virginia are eventually going to end up in the waters of both states because they don’t care about political boundaries. And the federal government doesn’t have well-defined authority to intervene,” he said.
By Todd McLeish
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