The Effect of Cow Nose Ray Predation on Oyster Restoration and the Use of Spat on Shell for Brood Stock Enhancement of Sanctuary Reefs A. T. Leggett, Jr., J. Wesson, S. K. Allen, R. Mann, M. Bryer, M. S. Congrove, E. C. D. Hudson International Conference on Shellfish Restoration Charleston, South Carolina, November 15-19, 2006

Virginia Oyster Landings and Bay Wide Restoration Goal  Years of over harvesting, habitat degradation and more recently, disease have decimated the Bay’s Oyster population  Active ecological restoration began in the early 1990s  The Bay wide goal is a 10 fold increase in the oyster population by 2010 Slide adapted from Stan Allen, VIMS Fishing MSX Identified Fishing Dermo Found Water Quality Degrades

Virginia’s Oyster Restoration Strategy  Recreate Habitat  Stock with wild oysters from buy back programs  Stock with selectively bred cultured oysters

Enter The Cow Nose Ray  Enter the Bay in May, leave during fall  One pup per year  Population has been increasing over the last several decades  Opportunistic feeders now focusing on oysters as other food sources have dwindled

Predator Exclusion  Erected around the sanctuary reef  Netting installed prior to ray arrival and removed in the fall  Brood stock planted safely during summer months  Designed to exclude rays using 5.75 inch mesh netting

Disadvantages of Predator Exclusion Devices  Costly  Labor intensive  Objections from other resource user groups  Impractical for large scale restoration

An Alternative to Net Pens  Joint CBF/TNC/VIMS/VMRC project  Rehabilitation of a reef by reshelling  Planting large brood stock  Time of year planting

Spat on Shell Used for Years for Commercial and Ecological Restoration  West Coast of the US  CBF MD and MD ORP

The Use of Spat on Shell for Ecological and Commercial Restoration in VA  With NOAA funding, industry, VMRC and VIMS produced and planted over 4 million spat on shell on 3 VA sanctuary reefs in 2005  CBF, VIMS and Bevans Oyster Co. deployed 4 million sterile native spat on shell on leased oyster ground for commercial oyster production in 2005

Spat on Shell Restoration Efforts Expanded in 2006  6 industry members, VMRC and VIMS produce over 20 million spat on shell for reef restoration with NOAA funds  CBF in VA in collaboration with VIMS ABC, sets up a remote setting station for spat on shell production

Effect of Rays on Spat on Shell  Rays have little impact on 2005 spat on shell placed on sanctuary reefs  Rays had little if any impact on the commercial plot  Rays do not appear to have an “interest” in newly deployed spat on shell

Future Plans  Industry, VIMS, VMRC collaboration to expand with double the participants in 2007  CBF in VA to expand to produce 5-6 million spat on shell in improvements to the shell washer -construction of setting cages to eliminate shell bags

Acknowledgements Special Thanks to all of the many CBF volunteers CBF Special Thanks to The Oyster Recovery Partnership Funding from The Nature Conservancy/NOAA CRP Partnership Funding for the VA CBF Spat on Shell Program was provided through a grant from RAE/NOAA Funding for the VIMS/CBF/Bevans Oyster Company project to commercially produce spat on shell was provide by NOAA Funding for the Industry/VIMS/VMRC spat on shell project was provided by the NOAA Chesapeake Bay Office  A. T. Leggett, Jr. and E.C.D. Hudson, Chesapeake Bay Foundation, 142 West York Street, Suite 318, Norfolk, VA  J. Wesson, VA Marine Resources Commission, 2600 Washington Ave, Newport News, VA  S. K. Allen, R. Mann, and M. S. Congrove, Virginia Institute of Marine Science, PO Box 1346, Gloucester Pt, VA  M. Bryer, The Nature Conservancy, 5410 Grosvenor Lane, Bethesda MD 20814