Bruce Smith: (603) 868-1095
John Nelson: (603) 868-1095
Jane Vachon: (603) 271-3211
October 12, 2007
Good News for Great Bay Oysters: Successful 2006 Oysters Continue to Thrive
DURHAM, N.H. -- Great Bay oysters had a very successful reproductive year in 2006, and continued monitoring suggests that this "year class" of oysters may prove instrumental in rebuilding Great Bay oyster stocks.
Over the past fifteen years, annual surveys by Fish and Game have measured the abundance of oysters on the major Great Bay beds. One important indicator of the health of the resource is the annual recruitment of young oysters into the population, termed "spatfall." Spatfall provides a clear picture of the reproductive success for a particular year, and these young oysters, or "spat," may become available for harvesters in about four years.
"Spatfall, determined by counts of newly settled oyster on shell, was the highest in numbers seen within the past fifteen years," said Bruce Smith, a marine biologist with the New Hampshire Fish and Game Department's Marine Fisheries Division.
A check on their survival last winter (2006-07) shows that the '06 set of oysters continues to thrive and grow, now being 2 to 2 1/2 inches in size. With further growth and development, these may provide an added boost to the overall reproductive potential for Great Bay Oysters. This is critically important in view of the current depressed state of this resource following large losses caused by disease and other negative environmental conditions. In fact, for some oyster areas, the '06 year class represents an opportunity for much-needed restoration of previously depleted stock. For that reason, N.H. Fish and Game will consider making rule changes in 2008 to conserve this important year class.
The record of spatfall over the fifteen-year period of study has clearly shown a lack of a steady and reliable supply of young oysters each year. The oyster population seems to vary widely in its ability to successfully complete its reproductive function; some years show little to no spatfall, and other years have relatively large numbers of spat.
Following is a short list of things oyster harvesters can do now that may help Great Bay oysters (and ensure that New Hampshire has a harvestable oyster crop in the future):
- Be especially careful when you cull shell brought up with tongs or rakes. Return as much shell as possible that has juvenile oysters attached.
- Avoid areas where only juvenile oysters are found. This is especially important at Nannie Island, where few mature oysters are found but where a heavy '06 set exists.
- Participate in the University of New Hampshire Jackson Estuarine Laboratory shell return program or return your shell after shucking to the beds when you next go oystering. This provides a favorable surface upon which settling oysters may attach.
"Thank you for your help in restoring Great Bay oysters," said Smith.
The New Hampshire Fish and Game Department is the guardian of the state's fish, wildlife and marine resources and their habitats.
- ### -