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Evaluating Oyster Shell Alternatives for Evaluating Oyster Shell Alternatives for Enhancing/Restoring Shellfish Beds and Enhancing/Restoring Shellfish Beds and
Associated ImpactsAssociated Impacts
Loren CoenLoren CoenMarine Laboratory, Sanibel-Captiva Marine Laboratory, Sanibel-Captiva
Conservation FoundationConservation [email protected]
K. SchulteK. Schulte**, A. Powers, A. Powers** , L. M. Taylor , L. M. Taylor * *, *MRRI-SCDNR , *MRRI-SCDNR
http://www.sccf.org, http://www.oyster-restoration.org/
All U.S. States (Atlantic, Gulf of Mexico, All U.S. States (Atlantic, Gulf of Mexico, C. vC. v.).)
*
0
5,000,000
10,000,000
15,000,000
20,000,000
25,000,000
30,000,000
35,000,000
40,000,000
45,000,000
50,000,000
Po
un
ds
of
Oys
ters
1975 1977 1979 1981 1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003
Years
Commercial Landings of Oysters from 1975-2003Connecticut
New York
New Jersey
Maryland
Virginia
North Carolina
South Carolina
Georgia
Florida East Coast
Florida West Coast
Mississippi
Alabama
Louisiana
Texas
SMRSR
Gulf
Percent decline (biomass, catch, percent cover) for fauna and flora from various marine environments.
Chart based on data from JBC Jackson, 2008.
Ecological extinction and evolution in the brave new ocean. PNAS 105 Suppl. 1
One year’s shell from a single Chesapeake Bay shucking houseTypical of 19th and early 20th centuries
Oyster Shell Getting Scarce
Going Elsewhere, Despite New Awareness and Going Elsewhere, Despite New Awareness and RecyclingRecycling
Recycle Oyster Shell
http://saltwaterfishing.sc.gov/oyster.htmlhttp://saltwaterfishing.sc.gov/oyster.html
Units deployed for shoreline ‘stabilization’ in Units deployed for shoreline ‘stabilization’ in TX (Mad Island Reefs) along the GICWW. TX (Mad Island Reefs) along the GICWW.
Recruitment and growth (< 1 year)Recruitment and growth (< 1 year)
Novel Approaches/Materials For Erosion Novel Approaches/Materials For Erosion ControlControl
Experiments by DISL Experiments by DISL (above) & Sea Grant (above) & Sea Grant
(below) to reduce (below) to reduce shoreline wave impacts shoreline wave impacts
Overview of TalkOverview of Talk Concerns about whether alternative materials or Concerns about whether alternative materials or
habitats can ever function as well as natural ones?habitats can ever function as well as natural ones? Large-scale attempts in VA, LA, TX (sorting, Large-scale attempts in VA, LA, TX (sorting,
interstitial space, longevity, weight) interstitial space, longevity, weight) Intertidal FocusIntertidal Focus For intertidal oyster resource/habitat restoration, are For intertidal oyster resource/habitat restoration, are
any alternative materials feasible under a range of any alternative materials feasible under a range of conditions?conditions? All things being equal (side by side)All things being equal (side by side) Bagged material vs. loose whelkBagged material vs. loose whelk
‘‘Shell’ vs. alternative materials for use in areas with Shell’ vs. alternative materials for use in areas with significant wave energysignificant wave energy Designed study to evaluate this along shoreline in National Designed study to evaluate this along shoreline in National
Wildlife Refuge in SC Wildlife Refuge in SC (in progress)(in progress) Novel methods for assessing restorationNovel methods for assessing restoration Following marsh erosion/mussels as stabilizers alsoFollowing marsh erosion/mussels as stabilizers also
Photo by J. Monck, SCDNR
Intertidal Oyster Reefs in Southeastern Intertidal Oyster Reefs in Southeastern U.S.U.S.
Flats vs. FringingReefs
REEF TYPE INTERSTITIAL VOLUME
Oyster shell 70%
Coal Ash 58%
Clam shell 45%
From M. Luckenbach
Materials Investigated (n = Materials Investigated (n = 7): Recruitment Trays7): Recruitment Trays
Fossil
Granite
Granite
Recycl. Concrete
Range, 48 lbs SC ShellTo >70 lbs for granite and Gulf Shell
X
Seven Alternatives in TraysSeven Alternatives in Trays
Deployed Trays in Blocks (4 total), Out for 90 Deployed Trays in Blocks (4 total), Out for 90 DaysDays
Each tray 2 m apart, each block is 22 m long with 15 m between blocks (n = 28, 7 x 4)
Granite,Avg. #4
GulfCrushed
Concrete,Avg. #4
SCLime-stone,
Avg. #4Whelk
Fossil Shell,Whole
Block 1
CrushedConcreteAvg. #4
FossilShell,Whole
Granite,Avg. #4
Lime-Stone,
Avg. #4Gulf Whelk SC
Block 2
Whelk SCCrushed
Concrete,Avg. #4
Lime-Stone,
Avg. #4
Granite,Avg. #4
Fossil Shell,Whole
Gulf
Block 3
SC GulfCrushed
Concrete,Avg. #4
Lime-Stone,
Avg. #4Whelk
Granite,Avg. #4
Fossil Shell,Whole
Block 4
5/07
22 m
2 m tray spacing
22 m
2 m tray spacing
22 m
2 m tray spacing
22 m
2 m tray spacing
Sign
Sign
Randomized Block DesignRandomized Block Design
361 days (2007-08) @Ashepoo/Coosaw Cut, SCORE/SCDNR
Trays Simple Way to Assess Larval Supply and Trays Simple Way to Assess Larval Supply and Growth Growth
Whelk 2F, 90 days Concrete 2A, 90 days
Tray Recruitment: Density (~3 Tray Recruitment: Density (~3 Mo.)Mo.)
A AA A
B B B
(n = 4; 7 materials)
AB AAB BD
C
(n = 4; 7 materials)
Tray Recruitment: Size (~3 Tray Recruitment: Size (~3 Mo.)Mo.)
Scaling-Up in the National Wildlife RefugeScaling-Up in the National Wildlife Refuge
ICW, Cape Romain NWR, SCICW, Cape Romain NWR, SC
ICW
ICW
Whelk Treatments, Side by Side Whelk Treatments, Side by Side Loose and Bagged in High Wave Energy AreaLoose and Bagged in High Wave Energy Area
2.5 Months After Planting, July to Oct.2.5 Months After Planting, July to Oct.
Results After 15 Mo.
LoosLoosee
BaggeBaggedd
>6 Months Post-Planting
Site 2: Site 2: R292 R292 Cape Romain NWR Cape Romain NWR
PlantingsErosion poles
In Progress: samples collected this In Progress: samples collected this weekweek
Protects fringing salt-marshProtects fringing salt-marsh Reduces bank erosion when Reduces bank erosion when
developeddeveloped Dissipate wave energy impactsDissipate wave energy impacts
Intact Intertidal Reefs as Natural Intact Intertidal Reefs as Natural BreakwatersBreakwaters
Shoreline >100 mShoreline >100 m shoreline (high erosion), washed shell soft sediment from marshshoreline (high erosion), washed shell soft sediment from marsh
High Wave Energy, Randomized BlocksHigh Wave Energy, Randomized Blocks5 of 7 materials Folly trays: 4 Reps.5 of 7 materials Folly trays: 4 Reps.
Looking from Block A to D. Each is 5 m2, 6 m between blocks; 3 m between ‘footprints’ within a block
Prep of SitePrep of Site(5 materials, 4 Reps.)(5 materials, 4 Reps.)
Delivery of Materials To Planting Site Delivery of Materials To Planting Site
Fossil,7/07 Gulf, 7/07 SC, 7/07 Limestone, 7/07 Concrete, 7/07
Fossil,7/07 Gulf, 7/07 SC, 7/07 Limestone, 7/07 Concrete, 7/07
Gulf, 7/07 SC, 7/07 Fossil,7/07 Concrete, 7/07 Limestone, 7/07
Fossil,7/07 Limestone, 7/07 Concrete, 7/07 SC, 7/07 Gulf, 7/07
Rep 1 Rep 1Rep 1 Rep 1 Rep 1
Rep 2 Rep 2Rep 2 Rep 2 Rep 2
Rep 3 Rep 3Rep 3 Rep 3 Rep 3
Rep 4 Rep 4Rep 4 Rep 4 Rep 4
Block 1
Block 2
Block 3
Block 4
Experimental DesignExperimental Design(4 blocks, 5 treatments = 20)(4 blocks, 5 treatments = 20)
Reef 3A, Recycled Concrete
Reef 1A, Fossil Shell
Reef 2A, Limestone
Reef 4A, SC Oysters
Reef 2B, Gulf Oysters
Five Materials Compared In NW Five Materials Compared In NW Refuge Refuge
Roughly 22-24 Containers Used/FootprintRoughly 22-24 Containers Used/Footprint
Little to no washSome Spat
Uniform PiecesReef 2A – Limestone
after 1 mo.
Little to no washSome Spat
Reef 1A – Fossil Shell
After 1 month
Little to no washSome Spat
Less Uniform PiecesReef 3A – Concrete
after 1 mo.
Some washSome Spat
Reef 4A – SC Shell, after 1 mo.Wash
Wash
Reef 5A – Gulf Shellafter 1 mo.
Little to no washSome Spat
Spat on Fossil Shell from Reef 1A25 spat counted on this
shell
1 Month After Planting
Recruitment (>2 mo.) Post-PlantingRecruitment (>2 mo.) Post-Planting
Survey Grade RTK GPS Survey Grade RTK GPS (Vertical and Horizontal, cm accuracy)(Vertical and Horizontal, cm accuracy)
March 08 (8 mo.)
SC footprints, later Gulf shell impossible to assess
Fossil
GulfGulf
Gulf
Block 1
Block 2
Block 3
Block 4
Blocks 3 & 4 not assessed
May 08 (10 mo.)
SC footprints, and later Gulf shell impossible to assess
Gulf
Gulf
Fossil
Gulfsc
Block 1
Block 2
Block 3
Block 4
Recruitment Assessments Recruitment Assessments in progressin progress
Preliminary Results: Change in Planted Preliminary Results: Change in Planted Material Area July 2007 vs. May 2008 by Material Area July 2007 vs. May 2008 by
GPSGPS
NQ NQ
NQ: not NQ: not quantifiable for quantifiable for SC/Gulf shell, SC/Gulf shell,
spread & movedspread & moved too much
NQ
Overview/SummaryOverview/Summary Most materials performed reasonably well Most materials performed reasonably well in traysin trays ((side by side) side by side) over an over an
extended period of timeextended period of time. . Use vs. LandfillUse vs. Landfill Larger, poorly-sorted Larger, poorly-sorted (variable-sized(variable-sized) ) materials did the best materials did the best (e.g., concrete), (e.g., concrete), lots oflots of
voidsvoids andand surface areasurface area for recruits, also moved less for recruits, also moved less Bagged materials, as demonstrated previously works better than loose Bagged materials, as demonstrated previously works better than loose
shell, especially in areas with wind or boat wave impactsshell, especially in areas with wind or boat wave impacts However, However, baggedbagged material is material is not feasible for larger projects not feasible for larger projects and still and still
cconcerns about stabilized plastic meshoncerns about stabilized plastic mesh ‘‘New’ molluscan shell (3) overall performed well relative to alternatives New’ molluscan shell (3) overall performed well relative to alternatives
(4)(4) Loose or bagged whelk shellLoose or bagged whelk shell consistently outperformed other shell, consistently outperformed other shell,
but is getting scarcer and scarcer to find in southeastern U.S.but is getting scarcer and scarcer to find in southeastern U.S. In ProgressIn Progress: but of the ‘shell’ treatments planted: but of the ‘shell’ treatments planted, , fossil shell fossil shell ((FL) FL)
performed well, as did denser materialsperformed well, as did denser materials (e.g., concrete) (e.g., concrete) in wave-washed in wave-washed areasareas
Novel approaches for assessing shell cover, etc.Novel approaches for assessing shell cover, etc. especially for intertidal especially for intertidal habitatshabitats Using surveying GPS can be a Using surveying GPS can be a ““rapidrapid” ” cost-effective method andcost-effective method and
highly repeatablehighly repeatable for assessing changes in intertidal planted for assessing changes in intertidal planted footprints over time, shoreline erosion, etc.footprints over time, shoreline erosion, etc.
Overhead camera methods also an alternative for smaller areasOverhead camera methods also an alternative for smaller areas
AcknowledgementsAcknowledgements