Evaluating Oyster Shell Alternatives Evaluating Oyster Shell Alternatives for Enhancing/Restoring Shellfish Beds for Enhancing/Restoring Shellfish Beds and Associated Impacts and Associated Impacts Loren Coen Loren Coen Marine Laboratory, Sanibel-Captiva Marine Laboratory, Sanibel-Captiva Conservation Foundation Conservation Foundation [email protected]K. Schulte K. Schulte * * , A. Powers , A. Powers * * , L. M. Taylor , L. M. Taylor * * , *MRRI-SC , *MRRI-SC http://www.sccf.org , http://www.oyster-restoration.org/
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Evaluating Oyster Shell Alternatives for Enhancing/Restoring Shellfish Beds and Associated Impacts Loren Coen Marine Laboratory, Sanibel-Captiva Conservation.
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Evaluating Oyster Shell Alternatives for Evaluating Oyster Shell Alternatives for Enhancing/Restoring Shellfish Beds and Enhancing/Restoring Shellfish Beds and
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.
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