Oyster Castles: A New Tool for Site Evaluation and Intertidal
Oyster Reef Habitat Restoration and Enhancement in Multiple U.S. East Coast States
Benjamin W. Stone 1
Peter Kingsley-Smith 1, Bowdoin Lusk 2, Barry Truitt 2, Joy Brown 3, Mark Faherty 4 & Gus Lorber 5
1 South Carolina Department of Natural Resources’ Marine Resources Research Institute
2 The Nature Conservancy Virginia Coast Reserve3 The Nature Conservancy South Carolina Chapter
4 Massachusetts Audubon / Wellfleet Bay Wildlife Sanctuary
5 Allied Concrete Co.
Background• Increasing pressure on coastal habitats• Multiple drivers of oyster reef habitat loss• Importance of ecological services• Decreasing availability and high price of
oyster shell• Use of novel materials as substrate• Suitability and potential success of reef
restoration and enhancement sites• Application of site evaluation approaches
Origin of the Oyster Castle
Virginia
South Carolina
Massachusetts
Massachusetts Audubon and Wellfleet Bay Wildlife Sanctuary
• Deployed June 2009• ~500 blocks divided
among 9 replicate castle arrays
• Density: Oysters m-2
• Size: Mean shell height (mm)
• Winter oyster mortality• Sites are open to
harvesting
Virginia Coastal Reserve• 3 sites established in June-July 2008
(~500 blocks) – November 2008 shown top right; October 2010 shown bottom right
• 2 additional sites established in June 2009 (~500 blocks)
• 1 site established in March-April 2010 on a larger scale (bottom left) and castles added to 2 existing sites (~1488 blocks)
South Carolina Oyster Castles• Deployed at 3 sites on Jeremy
Island in July 2009 using volunteers
• Eight arrays of 13 oyster castles
• Monitored quarterly from Dec 2009 until Nov 2010
• Castles constructed in Winyah Bay
Sampling Method
Bottom
Middle
Top Nor
th
Sout
h East
West
Photographed region
Elevationand
Orientation
Photographic analysis
AnalysisData from SC sites sampled in December 2009Oyster size data: oyster shell height (mm)Oyster density data: number of oysters m-2
Count no. of live oysters in each photograph (sample area)Determine sample area (m2) to calculate oysters m-2
Data tested for normality - assumptions of ANOVA modelsInvestigated main effects of site, elevation and orientation
and their interactionsNon-significant terms removed and reduced models re-runSplit analysis into the three sites-Casino, ICW, Skrine
Effect of elevation on oyster survival
•One-way ANOVA
• Significant at ICW & Skrine sites; not significant at Casino
• Tukey’s 95% C.I. post-hoc analysis
•ICW: Top > Bottom = Middle
•Skrine: Top = Middle > Bottom
Bottom Middle Top0
200400600800
100012001400
Skrine
Elevation
Oys
ters
m-2
Bottom Middle Top0
500
1000
1500
2000
2500
ICW
Elevation
Oys
ters
m-2
One-way ANOVASkrine only:
significantTukey’s 95% C.I.South = West > EastNorth not
significantly different from other orientations
Effect of orientation on oyster survival
North South East West0
200400600800
100012001400
Skrine
OrientationO
yste
rs m
-2
Oyster size analysesSignificance effects of:
SiteReplicate (castle)ElevationOrientationElevation*Orientation
Analysis ongoing
605040302010
9
8
7
6
5
4
3
2
1
0
shell height (mm)
% Fr
eque
ncy
CasinoMean=35.9 mm
605040302010
10
8
6
4
2
0
shell height (mm)
% Fr
eque
ncy
SkrineMean=25.47
mm
6050403020100
10
8
6
4
2
0
shell height (mm)
% Fr
eque
ncy
ICWMean=25.7 mm
ConclusionsCastles have utility as small-scale evaluation
tools and larger scale restoration substrate.Elevation significantly affects early post-
settlement oyster survival.Higher predation rates on lower elevations?Orientation affected survival only at one site
and patterns were not intuitive.Small-scale differences in oyster growth
rates.Success of restoration sites can be highly site
specific.
Acknowledgements Amanda Fornal 1
Ryan Joyce 2
Kristin Schulte 1
Eric Krueger 3
Kristine Hartvigsen 3
Mary Conley 3
Melissa Spotts 3 Neil Jordan 3
Pam Marfizo 3 Robert Newton 3 Ryan Olson 3 Sarah Hartman 3
Shari Wibert 3
Jim Yergin John Kooper Carl Kooper
Alec Adams Ashley Ammons David Mikell Jeanna Crockett Vicki Bullock Andrew Kazilieras Caroline Hetchell Kelly Courtney
South Carolina Department of Natural Resources 1
College of Charleston 2
The Nature Conservancy 3
Thank you for your attention.
Benjamin W. StoneWildlife BiologistShellfish Research SectionMarine Resources Research InstituteSouth Carolina Department of Natural [email protected]
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