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 Foundationlcoen@sccf.org

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