Oyster Reef and Oyster Reef and Estuarine Landscape Estuarine Landscape

RestorationRestoration

Kenneth L. Heck, Jr.Kenneth L. Heck, Jr.NGI Conference, May 2007NGI Conference, May 2007

Why Oyster Reef Why Oyster Reef Restoration ?Restoration ?

In addition to the multimillion dollar US In addition to the multimillion dollar US fishery they support, oyster reefs provide fishery they support, oyster reefs provide key ecological functions:key ecological functions:

-serve as habitat for finfish & shellfish-serve as habitat for finfish & shellfish-stabilize shorelines -stabilize shorelines -filter suspended solids and -filter suspended solids and

phytoplankton from the water columnphytoplankton from the water column-sequester excess nutrients -sequester excess nutrients

(nitrogen, phosphorous, and carbon)(nitrogen, phosphorous, and carbon)

Video of a healthy Alabama oyster Video of a healthy Alabama oyster reefreef

QuickTime™ and aH.263 decompressor

are needed to see this picture.

Program ObjectivesProgram Objectives

to develop the scientific understanding necessary to to develop the scientific understanding necessary to direct oyster restoration and enhancement in the direct oyster restoration and enhancement in the Northern Gulf of Mexico.Northern Gulf of Mexico.

to assist in developing a long-term strategy for to assist in developing a long-term strategy for sustained productivity of Gulf oyster reefs and the sustained productivity of Gulf oyster reefs and the associated ecological benefits that they provide.associated ecological benefits that they provide.

to provide this information to state and federal to provide this information to state and federal management agencies, the fishing industry and the management agencies, the fishing industry and the general public through outreach activities. general public through outreach activities.

Alabama Oyster FisheryAlabama Oyster Fishery(Source: NMFS)(Source: NMFS)

0

200,000

400,000

600,000

800,000

1,000,000

1,200,000

1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000

Landings (kg meat)

Frederic (3)

Opal (3)& Erin (2)

Camille (5)

Ethel (3) Elena (3)

Ivan and Katrina

X

Alabama Oyster HabitatAlabama Oyster Habitat

Live oyster reef

Buried oyster shell deposits

2007 Reefs

2008 Reefs

Restoration ChallengesRestoration Challenges• Dissolved Oxygen

• Recruitment

20 0 10 0 10 5

2

1

# spat m-2 d-1

(Hoese et al. 1972)

• Predation

Addressing ChallengesAddressing Challenges Reef CreationReef Creation

– Increased vertical relief of reefs may combat Increased vertical relief of reefs may combat low dissolved oxygen.low dissolved oxygen.

– Reef restoration for ecosystem benefits Reef restoration for ecosystem benefits Larval SupplyLarval Supply

– Repeat survey of Hoese (1972) and develop 3-Repeat survey of Hoese (1972) and develop 3-D hydrodynamic modelD hydrodynamic model

Living Shoreline ProtectionLiving Shoreline Protection– Stop shoreline erosion and stabilize marshesStop shoreline erosion and stabilize marshes– Enhance fishery habitatEnhance fishery habitat– Facilitate seagrass colonizationFacilitate seagrass colonization

Reef CreationReef Creation

Heck & Powers

Breakwater Reefs

Powers & Heck

Large reefs

Heck et al.

Ecosystem services study reefs

AL Marine Resources Divison Perdido Bay Reefs

Fisheries Habitat Fisheries Habitat ProgramProgram

Reef ElevationReef Elevation

u

High Relief (1.0

m)

Low Relief

(0.1 m)

2.5 m

1 m

2 m

Anoxic

Hypoxic

Normoxic

Cedar Point Reef Shellbank Reef

Sand Reef

1 HR

2 HR

3 LR4 LR

8 LR 7 LR

5 HR 6 HR

1 LR7 LR

8 LR

6 LR4 HR

5 HR

2 HR

3 HR

5 LR 6 HR

7 LR8 HR

4 LR

3 LR1 HR

2 HRCedar Point Reef Shellbank Reef

Sand Reef

1 HR

2 HR

3 LR4 LR

8 LR 7 LR

5 HR 6 HR

1 LR7 LR

8 LR

6 LR4 HR

5 HR

2 HR

3 HR

5 LR 6 HR

7 LR8 HR

4 LR

3 LR1 HR

2 HR

Fisheries Habitat Fisheries Habitat ProgramProgram

High vs. Low reliefHigh vs. Low relief

Cedar Point Reef Shellbank Reef

Sand Reef

1 HR

2 HR

3 LR4 LR

8 LR 7 LR

5 HR 6 HR

1 LR7 LR

8 LR

6 LR4 HR

5 HR

2 HR

3 HR

5 LR 6 HR

7 LR8 HR

4 LR

3 LR1 HR

2 HRCedar Point Reef Shellbank Reef

Sand Reef

1 HR

2 HR

3 LR4 LR

8 LR 7 LR

5 HR 6 HR

1 LR7 LR

8 LR

6 LR4 HR

5 HR

2 HR

3 HR

5 LR 6 HR

7 LR8 HR

4 LR

3 LR1 HR

2 HR

0

20

40

60

80

100

120

Low High

Reef Height

0

20

40

60

80

100

120

# L

ive

Spa

t / m

2

Low High

Reef Height

Fisheries Habitat Fisheries Habitat ProgramProgram

Cost - BenefitCost - Benefit

High relief reefs, 625 mHigh relief reefs, 625 m33 of of cultch @ $24 mcultch @ $24 m33 = $15,000 = $15,000

Low relief, 62.5 mLow relief, 62.5 m33 of cultch @ of cultch @ $24 m $24 m33 = $1,500 = $1,500

Note: 1 mNote: 1 m33 = 1.3 yd = 1.3 yd33, cost per , cost per ydyd33 ~ $18 ~ $18

Mobile Bay Results: June 2006 Mobile Bay Results: June 2006

Cedar Point Reef Area H

Sand Reef Area A

Shellbank Reef Area

Mobile Bay

Cedar Point Reef Area H

Sand Reef Area A

Shellbank Reef Area

Mobile Bay

0

20

40

60

80

100

120

140

# L

ive

Oys

ters

/ m

2

Cedar Point Reef Sand Reef Shellbank Reef0

20

40

60

80

100

120

140

# L

ive

Oys

ters

/ m

2

0

20

40

60

80

100

120

140

160

# L

ive

Spa

t / m

2

Cedar Point Reef Sand Reef Shellbank ReefSite

0

20

40

60

80

100

120

140

160

# L

ive

Spa

t / m

2

0

10

20

30

40

50

60

70

# D

ead

Spat

/ m

2

Cedar Point Reef Sand Reef Shellbank ReefSite

0

10

20

30

40

50

60

70

2

Fisheries Habitat Fisheries Habitat ProgramProgram

Oyster RecruitmentOyster Recruitment(Powers, Park, Graham)(Powers, Park, Graham)

Survey 18 sites Survey 18 sites throughout Mobile throughout Mobile Bay every three Bay every three weeks for oyster weeks for oyster settlement.settlement.

Jan 2006 – Dec 2007Jan 2006 – Dec 2007 Synoptic Synoptic

measurements of measurements of larval supplylarval supply

Fisheries Habitat Fisheries Habitat ProgramProgram

Spat Recruitment MethodsSpat Recruitment Methods

Fisheries Habitat Fisheries Habitat ProgramProgram

Predation: Oyster Drills

Fisheries Habitat Fisheries Habitat ProgramProgram

Spat/m2/day CR11 CR12 CR13

Larvae/1000L

30-100 μ

Larvae/1000L

100-500 μ

Source: C-K Kim

Living Shoreline Living Shoreline Restoration Restoration

GoalsGoals

Oyster reef Oyster reef construction, fish construction, fish use, shoreline use, shoreline stabilization, stabilization, marsh regrowth marsh regrowth and seagrass and seagrass colonization.colonization.

• Sparse biotic community

• Eroding shoreline

• Oyster bar foundation

• Shoreline stabilized

• Seagrass colonization?

• Some small fish and invertebrates

• Large oyster reef

• Expanded emergent marsh

• Expanded seagrass?

• Small and Large fish and invertebrates

• Sparse biotic community

• Eroding shoreline

• Oyster bar foundation

• Shoreline stabilized

• Seagrass colonization?

• Some small fish and invertebrates

• Large oyster reef

• Expanded emergent marsh

• Expanded seagrass?

• Small and Large fish and invertebrates

Filtration capacity of oyster Filtration capacity of oyster reefsreefs

http://http://www.youtube.com/watch?vwww.youtube.com/watch?v=1Zm-yMpHsaQ&feature=related =1Zm-yMpHsaQ&feature=related (click link to view video)(click link to view video)

Reef Construction at Point aux Reef Construction at Point aux PinesPines

Reef dimensions: 75 m long x 5 m wide x 1 m high

Monitoring of Replicated Areas Monitoring of Replicated Areas (with and w/o reef construction)(with and w/o reef construction)

Shoreline Stabilization Shoreline Stabilization Oyster Density and Oyster Density and

SettlementSettlement Water clarity (TSS)Water clarity (TSS) Chlorophyll a (water Chlorophyll a (water

column and benthic)column and benthic) Benthic Macroinfauna Benthic Macroinfauna Juvenile and Adult Fish Juvenile and Adult Fish

and Mobile Invertebratesand Mobile Invertebrates Seagrass ColonizationSeagrass Colonization

Historic Shoreline ChangeHistoric Shoreline Change

Erosion between 1978-1986 (actual date unknown) and 2006

Erosion between 2006-2007

Shoreline change: Point aux PinesShoreline change: Point aux Pines(May 2007 to May 2008)(May 2007 to May 2008)

• Estimate of shoreline change from marsh surveys

-3

-2.5

-2

-1.5

-1

-0.5

0

East West

Shoreline Change (m)

Control Reef

Shoreline change: Alabama PortShoreline change: Alabama Port

Data still being Data still being analyzed in ArcGISanalyzed in ArcGIS– Have shoreline data Have shoreline data

from December from December 2007, May 2008, 2007, May 2008, and pre-Gustav and pre-Gustav (August 29, 2008)(August 29, 2008) A

L 19

3

Bayfront Park

NOAA shapefile of shoreline, circa 2001

Line marking current shoreline, August 29, 2008

Large Fish: Gillnet Collections at Large Fish: Gillnet Collections at Point aux PinesPoint aux Pines

Some fisheries species enhanced Some fisheries species enhanced by oyster reefsby oyster reefs

Stone crabGag grouper

Speckled trout

Gray snapper

Southern flounder

Sheepshead Red drum

Blue crab

Summary (1)Summary (1)

Oyster restoration was successful in Oyster restoration was successful in that all reefs had live oystersthat all reefs had live oysters

Vertical relief did not have a Vertical relief did not have a pronounced impact on oyster pronounced impact on oyster density, although DO levels were density, although DO levels were rarely below 2mg/lrarely below 2mg/l

The Shellbank reefs (Bon Secour The Shellbank reefs (Bon Secour area) appear to be limited by larval area) appear to be limited by larval supply supply

Summary (2)Summary (2)

The breakwater reefs reduced wave The breakwater reefs reduced wave energy, trapped sediments, and reduced energy, trapped sediments, and reduced shoreline erosionshoreline erosion

Little change was seen in water clarity, and Little change was seen in water clarity, and no seagrass colonizationno seagrass colonization

Recruitment of oyster spat occurredRecruitment of oyster spat occurred Sport fish were attracted to the reefs Sport fish were attracted to the reefs Building such reefs may be a viable Building such reefs may be a viable

alternative to hardening shorelines, with alternative to hardening shorelines, with the added benefit of added fisheries the added benefit of added fisheries productionproduction

Cooperating/participating agenciesCooperating/participating agencies

National Marine Fisheries ServiceNational Marine Fisheries Service Alabama Marine Resources DivisionAlabama Marine Resources Division Dauphin Island Sea LabDauphin Island Sea Lab Mobile Bay National Estuary ProgramMobile Bay National Estuary Program Bon Secour Seafood, Inc.Bon Secour Seafood, Inc. Auburn University Extension ServiceAuburn University Extension Service University of South Alabama (Dr. University of South Alabama (Dr.

Sean Powers)Sean Powers)