This September marked twenty years since the first harvest of Spartina alterniflora from the constructed treatment marsh at the Stock Enhancement Research Facility (SERF). This initial harvest was used for coastal restoration near City Island in Sarasota Bay. The 1.9-acre effluent marsh was constructed and planted with 20,000 Spartina sprigs from a local wetland nursery. The marsh is connected to a two-acre settling pond that works together to filter nutrients and solids from hatchery discharge.
Spartina are harvested from the SERF marsh by an army of volunteers coordinated by FWC and like-minded partners for coastal habitat restoration. Plants are dug from the marsh and separated into plugs of two or more culms (stems), then counted and packaged into plastic bags for transport to restoration sites. Shoots, or single stem Spartina, are separated at harvest for school nurseries. Five thousand Spartina plugs are planted to restore one-acre of coastal marsh. Since 1997, almost 1.2 million plugs were harvested by partners and given to 67 restoration sites. These plants often grow rapidly at these restoration sites (photo below). Approximately 411,282 Spartina shoots were harvested from the FWC donor marsh and provided to establish 35 school nurseries for education and environmental awareness.
Recently, the variety of marsh vegetation used for restoration has expanded to include Paspalum vaginatum, a saltmarsh grass. In a short period of time over 28,000 plugs of Paspalum have been donated for coastal uplands restoration. This demonstrates that effluent donor marshes for fish hatcheries are an effective approach for hatchery wastewater treatment while supplying valuable native plants for coastal habitat restoration.
For more than 15 years, staff at FWRI’s Marine Hatchery in Port Manatee have been working with school administrators, teachers and students to bring Aquaculture and Stock Enhancement Research (SER) into the classroom. Aquaculture in the Classroom program is designed for students ranging from fifth grade through college, to teach them the basic principles of aquaculture, marine research and how stock enhancement plays a role in supporting Florida’s marine fisheries.
So how does it work? Staff at the Stock Enhancement Research Facility (SERF) provide participating schools hatchery-reared red drum (Sciaenops ocellatus) along with starter feed and technical advice on how to raise the fingerlings in the classroom. Information on system development and grant opportunities are also provided. At the end of the school year, the fingerlings are harvested and donated to local shelters or returned to hatchery to be used for outreach and education exhibits.
What do the students learn? SER staff work with teachers, who develop a curriculum that satisfies Florida Sunshine State Standards and provides students the opportunity to design aquaculture (fish-raising) systems, perform daily animal husbandry (care) routines and conduct research projects such as salinity tolerance tests, feed studies and water quality/chemistry investigations.
How many schools participate? Since this program began in 2001, more than 25 Florida schools from Miami to Pensacola have participated. This year, 10 schools participated statewide and 1,278 fingerlings were distributed. Many Schools like Crystal Lake Middle, Forrest Grove High and Canterbury School of Florida can rear fish all year round in recirculating aquaculture systems.
To learn more about the program, or to refer a teacher or school, please contact Gina.Russo@MyFWC.com.
Recently FWRI staff assisted Tampa Bay Watch and Southwest Water Management District staff in harvesting 40,000 Spartina alterniflora plugs from the effluent donor marsh at the Stock Enhancement Research Facility (SERF) in Manatee County. The Spartina plugs were pulled from the muddy marsh substrate, counted 100 plugs into black plastic bags for transport to the Rock Pond Restoration project in Hillsborough County, about one mile north of SERF, and replanted to coastal areas November 14, 2015. This planting follows up similar effort in which 30,100 Spartina plugs were harvested from the marsh and planted at the Rock Pond November 22, 2014. The Rock Pond Restoration encompasses 1,043 acres of coastal habitat, uplands, and palm tree hammocks and is the largest restoration project in the Tampa Bay area. Over the six day harvest period in November, the Spartina plugs averaged 5.1 culms or jointed stem per plug which equals a total planting of 204,000 Spartina to this site. The Rock Pond Restoration Project is one of 91 coastal recipients for Spartina plugs from the donor marsh since 1997. Total Spartina plugs from the SERF marsh is now 1,154,781 plugs and counting.
Maintenance of the genetic structure of a wild fishery is a key component for responsible marine stock enhancement. The historic model of spawning for stock enhancement of red drum in Florida’s Central Gulf coast required five 12-feet-diameter (12-ft) tanks with three female and three male adult red drum in each to achieve a satisfactory effective spawning population size. A single 20-feet-diameter (20-ft) tank, five times the volume of a 12-ft tank, for spawning 30 adult red drum presents opportunities to improve efficiency through reduced logistical complexities, labor, and footprint, while maintaining or improving genetic diversity of hatchery offspring in Florida Stock Enhancement Hatcheries. A study is in progress at SERF to determine the effective population size of spawning red drum in a 20-ft tank to determine if this strategy is a more efficient alternative than the historic model.
A key consideration before implementing the study was to design and construct a prototype filtration and egg collection system that could be used with the 20-ft tank. Traditional filtration systems for spawning tank are not efficient for large tanks. The new spawning system designed and tested by SER team members reduced water use and labor, and improved water chemistry from the traditional design. These improvements were keys to effectively operate a large spawning tank. SER staff then adapted the prototype design for a 20-ft-tank. Construction and assembly of the spawning system was accomplished by SER staff and key functions tested and refined before stocking fish.
Adult red drum were stocked into the 20-ft tank and a 12-ft tank on November 4 and 6, 2014 to evaluate husbandry and maintenance of the 20-ft tank. Although not expected necessarily, spawning commenced soon afterward in both tanks as fish were stocked at the end of the natural spawning season. Beginning in late January, the red drum captive maturation cycle (a compressed seasonal cycle of 150 days) was initiated. Spawns began in July and are being collected for through October 2015. The spawning contribution of the individuals in the 12-ft and 20-ft tanks will be determined using genetic markers over the course of the four-month spawning period and replicated with new populations of red drum in subsequent years. This data is a key to the design and operation of stock enhancement facilities in Florida and other states that subscribe to approaches for maintaining the genetic structure of wild red drum populations.
The internal newsletter of the FWC Fish and Wildlife Research Institute