Martin County Coastal Engineering Divisionwww.martin.fl.us/GOVT/

Artificial Reefs

Kathy FitzPatrick, P.E.,Kathy FitzPatrick, P.E.,

Coastal EngineerCoastal Engineer

Martin County Engineering Martin County Engineering DepartmentDepartment

Kathy FitzPatrick, Kathy FitzPatrick, P.E.,P.E.,

Coastal EngineerCoastal Engineer

Martin County Martin County Engineering DepartmentEngineering Department

Presentation OutlinePresentation Outline

• Purposes of Artificial ReefsPurposes of Artificial Reefs

• Types of Artificial ReefsTypes of Artificial Reefs

• Design FactorsDesign Factors

• Materials for Building ReefsMaterials for Building Reefs

• ExamplesExamples

• Martin County’s ProgramMartin County’s Program

Martin County Offshore AR Sites

Artificial ReefsBenefits

• Increase habitat- Sessile marine organism- Juvenile fishFeeding ground for adult reef

and pelagic fish• Decrease stress on natural reefs• Provide mitigation opportunities

Types of Artificial ReefsTypes of Artificial Reefs

• Individual Units– each unit provides surface areas & void

spaces all by itself– each individual unit must be stable

• Rubble Mound (Stacked) Units– spaces between units provides void spaces– interlocking of units promotes stability

Individual Reef Ball™ Unit

Rubble Mound Tetrahedrons

EngineeringEngineeringDesign FactorsDesign Factors

• water depth - structure purpose

• unit size - weight, stability, anchoring

• vertical & horizontal relief

• surface area & void spaces

• durability & longevity

• waves , currents, and tides

• scour, deposition, settlement

• environmental effects

MaterialsMaterials• Waste Disposal (material of opportunity)

Metals - ships, planes, etc.Concrete –bridge material, culverts, construction

debris, etc. Porcelain – sinks, toilets, etc. Rubber - tires, tire chips

• Custom Fabricated UnitsConcrete - new or waste, w/wo additivesNative Rocks - rubble mound or cemented Containers - concrete, sand, or water filled

Florida Artificial Reef ProgramFlorida Artificial Reef Program

Materials Placed 1991-96Materials Placed 1991-96

Concrete Modules

10%

Steel Vessels

15%

Fiberglas Boats

1%Limestone Rock7%

Waste Concrete

67%

Ship Ship DisposalDisposal

for for Artificial Artificial

ReefsReefs

Boeing 727Boeing 727 -- Preparation for Preparation for Sinking OffshoreSinking Offshore

727 Deployment727 Deployment

727 Underwater727 Underwater

DERM Artificial Reef Modules -DERM Artificial Reef Modules - Module FabricationModule Fabrication

DERM Module DeploymentDERM Module Deployment

DERM Module UnderwaterDERM Module Underwater

RECYCLING USED TIRESRECYCLING USED TIRESPast …..Past …..

…….AND PRESENT.AND PRESENT

Deployment of Concrete Deployment of Concrete TetrahedronsTetrahedrons

Colonization of Tetrahedron ReefsColonization of Tetrahedron Reefs

Reef BallReef BallTM TM Units Units (RBDG, Ltd.)(RBDG, Ltd.)

Port Canaveral Port Canaveral Reef BallsReef Balls

70’ water depth

Snorkel Trail Signs on Provo, Snorkel Trail Signs on Provo, Turks & CaicosTurks & Caicos

Providing New Reefs and Protecting Existing Reef Areas

Worm Reef Worm Reef Growth on Growth on Concrete Concrete Artificial Reef Artificial Reef ModulesModules

ConclusionsConclusions• The design of artificial reefs incorporates both engineering

and biological elements. • Reef units must be designed to be stable, durable, and

with adequate longevity.• Artificial reef modules can serve “double duty” when also

incorporating recycled materials• Underwater habitat can be increased and stress reduced on

natural reef systems by constructing artificial reef sites.• Many designs for artificial reef modules already exist and

have been deployed off the Florida coast

Martin County’s Artificial Reef Program

• Evans Crary Bridge Deployment – 2000• Tetrahedron Construction (single mound) – 2000• Tetrahedron Construction (patch reef) – 2001• FEC Railroad ties – 2001/2002• Impoundment basin deepening rock – 2002/2003• “River Reef” – 2003• Jensen Causeway Bridge – 2004/2005

Evans Crary Bridge

Artificial ReefsMartin County

Nearshore - Site 3Nearshore - Site 2

Donaldson ReefSirotkin Reef

Ernst Reef

Nearshore - Site 1

Tetrahedron Site

Inlet Rock Site

River Reef site 1

River Reef site 2

Donaldson Reef

Inlet Rock Site

Ernst Reef

Evans Crary Bridge

Sirotkin Reef

Tetrahedron Site

Nearshore Reef Sites

Nearshore Mitigation Reefs

• FDOT specifies offshore disposal of Evans Crary Bridge

• Nearshore reefs areconstructed with pilings from the bridge

• … at NO COST to the County

Nearshore Reef Site 3

Nearshore Reef Site 2

Nearshore Reef Site1

Artificial ReefPartnerships

• Mitigation for Beach Renourishment Projects- Partner with FDOT, FDEP, FOS

• Disposal for Impoundment Basin Rock- Partner with Corps, FOS

• Railroad Tie Disposal- Partner with FEC, FDEP, FOS

• Oculina Coral Recruitment- Partner with FFWCC, FOS

Martin County’s FutureMartin County’s Future

• Continue construction on planned projects• Increase public awareness and “buy-in”

– Brochures– Publicity events– Public education and involvement opportunities

• Search out new funding sources– State and Federal grants– Increase local funding base

• Identify new projects through public input

Wave Gage and Beach Cam

Thank You

Martin County Coastal Engineering Divisionwww.martin.fl.us/GOVT/