Michael Hodges*, William Anderson, Nancy Hadley, Holly Dyar, Allison Kreutzer South Carolina Department of Natural Resource Office of Fisheries Management Shellfish Management Section
SCDNR is conducting mitigation for seaport expansion by the South Carolina State Ports Authority Minimum of eight acres of intertidal oyster reefs will be constructed after 5 years 7.26 acres of shoreline have been planted at 24 sites since 2008 Approximately 125,000 bushels of oyster shells will be planted along shorelines in Charleston Harbor watershed Community volunteer component to the mitigation project Oyster reefs will be monitored for certain success criteria by SCDNR staff
SCSPA is constructing a new 286 acre container port on the Cooper River (highlighted in red) This will be the 5 th port in the Charleston Harbor watershed (highlighted in red) Currently there are two container terminals and two break bulk terminals The new port will increase the capacity of the Port of Charleston by 1.4 million twenty-foot equivalent units (TEU), currently at 2.6 million TEU Photo provided by SCSPA
The SCSPA’s terminal mitigation plan includes more than $10 million in environmental and community mitigation activities. $1 million to restore 8 acres of oyster reefs for direct impacts to aquatic resources and wetlands $2.5 million to recreate 22 acres of tidal marsh on Drum Island $2 million for land protection for indirect environmental impacts and serve the public interest $4 million in community programming to fund education and job training programs, establish an affordable housing trust and other projects. Photos courtesy of SCSPA
SCSPA provided funding to SCDNR to be used for the purpose of restoring, enhancing and monitoring eight acres of living oyster (Crassostrea virginica) reefs Reefs are to be constructed in Charleston Harbor watershed Reefs will be placed in intertidal areas pre- determined by SCDNR Planting of shells will be contracted out to industry professionals Planting sites will be monitored by SCDNR staff pre/post shell deployment
Oysters are designated as essential fish habitat (EFH) by The South Atlantic Fishery Management Council (SAFMC) Federally managed species that depend on oysters include red drum (Scienops ocellatus)and Penaeid shrimp In S.C., intertidal oyster reefs generate biodiversity and are identified as critical habitats of concern in both the State Conservation Plan and DNR’s Comprehensive Wildlife Conservation Strategy Oysters filter water, thus improving water quality and clarity Intertidal oysters provide structure to aid in shoreline stabilization and erosion prevention Photo courtesy of Affinity Charters
Consists of Charleston Harbor (20.7 km 2 ), 3 Main Rivers (Cooper, Wando and Ashley Rivers), and associated Tidal Creeks Numerous Industrial, Commercial and Residential areas on Harbor and Main Rivers Part of Intercoastal Waterway (ICW) High wave energy from currents, container ships, recreational boat traffic Run off from surrounding impervious surfaces, coastal development and the SC upstate High commercial/recreational pressure from boating and fishing
Funding is difficult to obtain for restoration in areas closed to shellfishing Mitigation is one of the few avenues for obtaining funding in these areas Projects requiring mitigation often have a difficult time finding suitable projects that meet objectives Finding suitable restoration sites can be challenging in areas of interest (i.e. wave energy/currents slope, bottom type) Pic of closed waters
10.83 acres (44 sites) of restorable shoreline has been mapped with Trimble GPS Pro® 7.26 acres (20 large scale sites, 4 small scale) have been planted since Summer acres (10 sites) will be planted in acres will be constructed by community volunteers
Oyster shell (Crassostrea virginica) and mined shell aggregates are purchased and delivered from Florida and North Carolina ( bushels/delivery) Shell prices are based on cost/bushel including delivery (increasing every year) To date we have purchased 82,715 bushels of material Shell is loaded onto contractors barge with bobcat and conveyor loader Barge is able to transport bushels per trip Shell is transported to predetermined sites, Transport time is between minutes based on site location Photo courtesy of L.Coen
Shells are deployed from barge using high pressure water cannon at high tide Outer boundary of area to be restored is marked with 10’ PVC stakes SCDNR monitors planting of shell to insure proper placement within staked boundaries Volume of shell planted is based on size of restoration site (10,000-12,000 bushels/acre) Deployment time is minutes
>70% vertical live oyster at the end of three years Density, mean and max size of oysters will be within 1 SD of natural populations after three years Population parameters of restored reefs will meet or exceed F 1 Strata characteristics 1,926 bushels live oysters/acre Size distribution after 3 years will include at least 30% recruits (<25mm) to insure reef propagation
12 season grand mean = 4267 oysters /m 2, 2 Season SPA mean = 3143 oysters/m 2 (6 sites)
Long Term Average= 4048 oysters/m2 SPA Average= 1321 oysters/m2
Ranking sites based on Natural Resource Restoration Targets Clouter Wando Beresford 31b Wando 28b Hobcaw 23b Hobcaw 23a Horlbeck Wando Beresford Beresford 1a Horlbeck Beresford Hobcaw 25a Beresford Hobcaw Clouter Beresford Density of small oysters #/m 2 Good>1400 Fair Poor<450
August 2008 January 2010
Monitoring Changes in Shoreline Changes in sediment composition Pre-construction vs. Post construction (annually) Spartina Expansion Pre-construction vs. Post construction (annually) Marsh edge erosion (annually at selected sites)
Community-based habitat restoration and monitoring program of SCDNR Allows community volunteers to work with scientists to restore and monitor oyster habitat along the South Carolina coast Increase oyster habitat at a minimum cost to taxpayers Develop a citizen constituency for oysters Initiate a grass-roots effort to restore oysters Increase public awareness of the value of oysters to the ecosystem
Uses 2/3 bushel of shell per bag Shell bags are made and deployed by volunteers Can be constructed in higher energy environments than large scale reefs acres will be constructed after 5 years Increased shoreline stabilization compared to large scale reefs Can be used as living classrooms for school groups Sites can be used for volunteer fish sampling efforts Water quality is monitored by volunteers at restoration sites
Documented Success=Future Funding for other Mitigation Projects >8 acres of oyster reefs established 8 acres of habitat for fish, crab, fish and organisms associated with oyster reefs Increased water filtration Improved water quality Denitrification Shoreline stabilization/erosion prevention Involving the public in restoration efforts
South Carolina State Ports Authority SCORE Volunteers and Organizations SCDNR Employees Contract Employees (Capt Pee Wee, Capt Hatt, Froggy, Chip, Trey) Delivery Drivers (Disco, Brian, Todd, Jim) Shell Suppliers