The World In Your Oyster Bed

A new study published in the journal Oecologia reveals that California oyster beds are under attack from introduced species, including Atlantic snails and the European green crab.

Chesapeake Bay Goes Native

After five years of research and deliberation, officials in Maryland and Virginia have decided against plans to replenish the Chesapeake Bay's oyster bed by reseeding it with Asian oysters (Crassostrea ariakensis). Instead, looks like they will be focusing their efforts on the native C. virginiensis. This article in The Baltimore Sun indicates that there is still a chance of some limited testing with the Asian oysters in the future.

Sterile Is A State Of Mind

WTOP News is reporting that around 100 Asian oysters (Crassostrea ariakensis) "escaped" from their cage in the Chesapeake Bay after being hit by a boat anchor. Of course, being oysters, they didn't just run off, but they are missing (more than 500 other oysters from the same cage were recovered). Part of an experiment to determine the feasibility of raising Asian oysters in the Bay, the test subjects were sterile, though there is a small risk that sterilized oysters can revert back to being sexually viable. Scientists say the chance of the escaped oysters having even survived the incident is small.

Tip of the virtual hat to the Smalltalk blog for posting about this story.

Oy to the World

The AP is reporting that a team of workers removed more than 250 individuals of an introduced, unindentified species of oyster from San Francisco Bay last week. The oysters are massive compared to the native versions, with shells as much as nine inches wide. While the first known occurrence of this species in the bay was likely an empty shell found back in 2004, no sign of a live specimen was ever seen until this find. For more information, check out this expanded story (.pdf) and this audio report and excellent photo over at NPR's website.

New Oyster Cult

Apparently patience is not a virtue, at least if you are on the Virginia Seafood Council. According to this article from the Virginia Pilot, the VFC, fed up with declining harvests of native Bay oysters (Crassostrea virginica), has asked the state Marine Resources Commission to approve the release of Asian oysters (Crassostrea ariakensis) into the Chesapeake Bay. Biologists are urging the state to wait until the completion a 3-year federal study of the possible impacts of the introduction before making a decision. Politics is probably playing a strong role here, with the state upset that the federal government is trying to regulate their waters, and the Army Corps of Engineers supporting a native oyster restoration project.

Interested readers may want to check out previous ISW posts about Asian oysters: 1, 2.

Oysters Clam Up

Louisiana oyster farmers are concerned about the effect that importing and growing live bivalves will have on their industry. As reported by The Times-Picayune, their focus is on two problems: 1) Asian oysters (Crassostrea ariakensis) that are being seeded into the Chesapeake Bay, and 2) green mussels (Perna viridis) that were introduced by ballast water and threaten Louisiana oyster beds. If you are interested in the subject of introduced oysters, be sure to check out the book "Nonnative Oysters in the Chesapeake Bay," which is available in its entirety on the web here.

Bonamiasis

Scientists from the Virginia Institute of Marine Science recently discovered a new protozoan parasite (Bonamia sp.) in populations of Asian oysters (Crassostrea ariakensis) off the coast of North Carolina, according to this report from ABCNews.com. This is bad news, as many had hoped that the Asian oysters could supplement the Chesapeake Bay's dwindling native oyster populations. This is the first time that Bonamia has been found in the region, though it has been detected in Maine, France and New Zealand. Research is still being done to determine where the parasites are from (they don't appear to be associated with the shipments of Asian oysters), and to what degree they cause oyster mortality. Bonus points to ABCNews for using scientific names.

No such thing as 100%

The Washington Post has an interesting article about plans in Maryland and Virginia to release Asian Suminoe oysters, to replace the dwindling stocks of native species. Some of the oysters (Crassostrea ariakensis) are from populations bred with an extra chromosome, and while this is supposed to make them sterile, it is not 100% effective. Experiments are already underway to test the oysters' ability to thrive in the Atlantic Ocean. Meanwhile, some officials are concerned about the potential of these bivalves to introduce disease or to become invasive themselves. Bonus points to the Post for using the scientific name of the oyster.