Shellfish aquaculture a bright spot in weak economy

  • Clam Bags   Hard clams ready for market.   © K. Hudson/VIMS.
  • Oyster Cages   Intensive culture uses cages to protect oysters from predation.   © K. Hudson/VIMS.
  • Oyster Shells
    Oyster Shells   Young oysters prefer to settle on oyster shells like these.   © C. Rose/VASG.
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Virginia’s oyster aquaculture industry is growing steadily despite the struggling economy and some setbacks in hatchery production, according to a report from the Virginia Institute of Marine Science and Virginia Sea Grant.

In 2011, oyster growers sold more than 23 million oysters worth more than $6.7 million—up 38% from 2010. The state’s clam aquaculture industry is holding steady and remains the largest in the nation, producing 450 million clams worth $26 million. Both oyster and clam prices remained stable in 2011.

In recent years the state’s oyster aquaculture industry has expanded from "intensive culture" of single oysters from hatchery seed into "extensive culture" or “spat-on-shell” planting. In intensive culture, growers plant relatively small numbers of individual oysters within floating cages, then carefully tend them for harvest in the half-shell market. In extensive culture, growers allow oyster larvae to settle on old oyster shells in large tanks, plant the resulting spat or seed oysters in the field almost immediately, and then allow them to grow freely on the bottom into clumps of oysters that are harvested for sale as shucked meat.

“Our greatest potential for expansion lies in extensive oyster culture and hatchery production of eyed oyster larvae,” says Karen Hudson, Shellfish Aquaculture Specialist at VIMS and co-author of the report. Efforts to develop new large-scale plantings using the techniques of extensive culture—which have received a boost from a variety of grant funding sources—are now beginning a transition to full support through industry earnings. Hudson and co-author Tom Murray, associate director of the Marine Advisory Services program at VIMS, plan to add data about extensive-culture techniques and results to future reports.

The 2011 Shellfish Aquaculture Report. Click to download pdf.Virginia oyster hatcheries have undergone a rapid expansion that began in 2008, but experienced some growing pains in the summer of 2011. Hatchery production is once again moving in a positive direction and the forecast looks promising for increased production of eyed larvae in 2012. Eyed-larvae production to supply spat-on-shell culture is a prerequisite for continued growth in that sector. Virginia oyster and clam hatcheries both supply primarily in-state aquaculture operations, whose eventual market is primarily out-of-state. This adds significantly to the overall value of the industry to the Commonwealth’s economy.

The “Virginia Shellfish Aquaculture Situation and Outlook Report” has been produced annually by Virginia Institute of Marine Science and Virginia Sea Grant since 2005. Download the report as a pdf.