Bay tributaries in Virginia waters were assigned to the following
basin categories: Potomac tributaries (includes Nomini Creek,
Coan River, Yeocomico River), Great/Little Wicomico, Rappahannock
(includes Corrotoman River), Piankatank, York/Mobjack Bay (includes
East, North, Ware, Severn, and Perrin River), Poquoson/Back, James
(includes Elizabeth, Lafayette, and Nansemond Rivers), Lynnhaven,
and Eastern Shore/Tangier (includes Tangier and Pocomoke Sounds
as well as all Bay side tributaries of Virginia's Eastern Shore).
These basins are shown on the map below.
Basin estimates are available for Virginia oyster populations
from 1994 through 2008. These basin estimates rely on a variety
of different data types that are collected by different agencies
and institutions. All data used in Virginia oyster population
estimates fall into one of 4 categories: fishery independent,
fishery dependent, restoration, or oyster aquaculture. Each of
these categories is described briefly below.
Independent data - These data are collected during annual patent
tong surveys conducted by the Virginia Institute of Marine Science
and the Virginia Marine Resources Commission. These surveys use
a hydraulic patent tong deployed from the research vessel J.B. Baylor which samples 1 square meter of bottom at each sample. 2005 data also reflect the extensive survey of the Lynnhaven River system completed by Dr. Mark Luckenbach and colleagues at the VIMS Eastern Shore Laboratory for the NORM program.
B1. Public/Commercial fishery - These data are based on the oyster
landings as reported to the Virginia Marine Resources Commission
by commercial fishermen. The data are provided for this exercise
by the Virginia Marine Resources Commission Fishery Statistics
B2. Private fishery - These data are based on the oyster landings
as reported to the Virginia Marine Resources Commission by private
leaseholders. The data are provided for this exercise by the Virginia
Marine Resources Commission Fishery Statistics Department.
C1. Reefs - unexploited sanctuaries - since the early 1990s, the
Virginia Marine Resources Commission Shellfish Replenishment program
in collaboration with the Virginia Institute of Marine Science,
the Virginia Department of Environmental Quality, and other state
and federal agencies has been actively building three dimensional
reefs in an effort to restore some of oyster reef habitat that was
historically dominant in the lower Chesapeake Bay. These reefs are
sanctuaries for oysters in that the oysters are neither fished nor
disturbed and these reefs serve as sources of oyster larvae for
the surrounding waters. The Virginia Marine Resources Commission
Shellfish Replenishment program conducts annual surveys of the oyster
populations on these reefs. These data are provided courtesy of
the Virginia Marine Resources Commission Shellfish Replenishment
C2. Replenishment areas - exploited shellplants and reefs - each
year the Virginia Marine Resources Commission Shellfish Replenishment
program plants shell and oyster seed at various sites in Virginia's
tributaries to enhance fishery production and restoration activities.
The data on the number of oysters planted by location were obtained
from the annual Virginia Marine Resources Commission Shellfish Replenishment
program Repletion reports.
D. Oyster Aquaculture
D1. Oyster gardening/planting - Data on oyster planting activity by the Chesapeake Bay Foundation are provided courtesy of Mr. Tommy Leggett and the Chesapeake Bay Foundation and detail oyster planting
on constructed sanctuary reefs in Virginia waters by private citizens, students, and other groups. This category also includes broodstock oysters planted on sanctuary reefs in the Great Wicomico River during 2004, 2005, and 2006 as part of ongoing native oyster restoration efforts by the Virginia Institute of Marine Science, the Virginia Marine Resources Commission, NOAA Chesapeake Bay office, the Chesapeake Bay Foundation and the U.S. Army Corps of Engineers (see www. vims.edu/mollusc/NORM for additional details).
of oyster populations within Virginia's basins made with these
data categories are available for:
Please note that VA Basin estimates for 2005 are in DRAFT format as of 2/23/2010. The posted 2005 estimates reflect fishery dependent data that were available as of 2/23/2010. As additional data become available THE 2005 ESTIMATES WILL CHANGE. Please refer back to this web site for updated estimates for VA Basins in 2005.
estimates of oyster population numbers and biomass (g dry tissue)
are useful for describing trends in Virginia's oyster population
over time. View graph of Virginia oyster
numbers and biomass in the period 1994-2008.