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FY13-14 – Sustainable Fisheries and Aquaculture


New Businesses are producing high value single oysters following the success of local pilot project  
PI: Julie Davis, S.C. Sea Grant Consortium

Market demand is increasing across the nation for premium single oysters branded according to the waters in which they are grown. In South Carolina, single oyster production from wild harvest has dwindled and alternative methods, such as farming oysters, are required if South Carolina is going to capitalize on market trends. Off-bottom oyster farming methods can readily and economically address local fouling challenges and help growers enter premium markets.

RESPONSE: With funding from a National Sea Grant Aquaculture Extension grant, South Carolina Sea Grant Consortium’s living marine resources extension specialist worked in co-operation with two industry partners to install off-bottom oyster cages best suited to the growers’ demonstration sites. Industry partners assisted with bi-monthly monitoring and routine husbandry at the two demonstration sites. Additional prospective growers are receiving technical expertise and site visits upon request. Testing of additional gear types is expected in 2014.

RESULTS: Encouraged by the quality of the oysters produced using off-bottom methods, three new businesses have been created that are using off-bottom methods and three more are expected to begin production in 2014. This represents investments of roughly $70,000 and a potential result of $540,000 farm-gate value production in the coming year.

South Carolina shellfish growers are expanding into the high-value single oyster market utilizing off-bottom production techniques with assistance provided by the South Carolina Sea Grant Consortium.

Public-Private Partnership to Assess Health of South Carolina Horseshoe Crab Population            
PI: Julie Davis, S.C. Sea Grant Consortium

South Carolina horseshoe crabs (HSC) are collected for their blood which is used to test for contamination in intravenous medications and medical equipment. The bleeding has been shown to result in a mortality of 10-20% of collected crabs. Other states harvest HSC for bait, resulting in much higher mortality. Coastal visitors and residents frequently report stranded HSC on spawning beaches, resulting in negative media attention.  South Carolina lacks information on local HSC populations. Research on this HSC population would provide state-specific information to coastal visitors and provide resource managers with the data they need to conserve and protect the resource.

RESPONSE: The South Carolina Sea Grant Consortium organized and facilitated a meeting between scientists, resource managers, and fishermen to discuss HSC research needs. It was determined that use of a genetic approach to determine the effective population size, paired with an age structure study, is the best way to assess the health and sustainability of the horseshoe crab population.

RESULTS: Endosafe/Charles River Lab, a biomedical firm that bleeds horseshoe crabs committed, funding for a multi-year study to determine the status of the South Carolina population. They provided an initial $27,663 to the Consortium for the first year to screen, select, and optimize molecular markers for the genetic characterization of SC horseshoe crab populations. DNA samples will be collected from adult and juvenile horseshoe crabs on harvested and unharvested spawning beaches. The Consortium, in cooperation with the fishing industry and in partnership with the SC Department of Natural Resources, will lead the study.

RECAP: The South Carolina Sea Grant Consortium, in partnership with South Carolina Department of Natural Resources and the fishing industry and with funding from private industry, is conducting a multi-year study to determine health of the South Carolina horseshoe crab population.

Amended Dock Ordinance Improves Access for the Shellfish Farmers in Beaufort County            
PI: Julie Davis, S.C. Sea Grant Consortium

In Beaufort County, a dock on a small tidal creek can only be used for commercial purposes if located within a Commercial Fishing Village Overlay District (CFVOD). CFVODs were created to preserve historic infrastructure for traditional fisheries. Production from traditional fisheries is declining while shellfish mariculture production is increasing. This emerging industry has water access needs that differ from those of traditional fisheries because it uses different waterways and boats, and needs rapid access to refrigeration for the live, raw product being marketed. Beaufort County’s Director of Planning sought expertise from the South Carolina Sea Grant Consortium (SCSGC) regarding shellfish mariculture methods and regulations in order to inform decision making about a proposed text amendment to the Dock Ordinance.

RESPONSE: Consortium extension staff met with Beaufort County’s Planning Director and Assistant Director to understand their needs and then , using information provided by the National Sea Grant Law Center about other South Carolina regulations that pertained to commercial activities on docks in small tidal creeks, provided a five-page overview document describing shellfish mariculture methods, markets and regulations. This document was used by Planning staff to educate County Council members.

RESULTS: After three unanimous votes by Beaufort County Council, the dock ordinance was amended to allow docks on small tidal creeks to be used for landing maricultured shellfish as long as the upland property is zoned for mariculture activities and the landowner possesses all required state mariculture permits. 

RECAP: After receiving educational materials from the South Carolina Sea Grant Consortium, Beaufort County Council votes to amend Dock Ordinance improving access to shellfish mariculture leases and ensuring a safe, sustainable supply of locally grown shellfish.


Demonstrating Clam Culture Techniques for Beginning Farmers
PI: Julie Davis, S.C. Sea Grant Consortium

Shellfish aquaculture is one of the fastest growing seafood producing methods with potential for growth in South Carolina, but shellfish resources in South Carolina have historically been underutilized with approximately 90,000 US Bushels of oysters and 15,000 bags of clams (250 count) produced annually. Indeed, many wild shellfish harvesters and shrimp fishermen have expressed interest in learning shellfish culture techniques in order to diversify their fishing businesses.

RESPONSE: The Consortium initiated clam demonstration projects with two new private sector shellfish culturists in the fall of 2011. The project team planted seed clams at two sites in Charleston and Beaufort counties which are being used to demonstrate the effects of planting density and season on growth and survival. Additionally, the projects serve as demonstrations for potential farmers to learn how to use these specific planting methods.

RESULTS: To date, two new and beginning private sector shellfish culturists are learning about clam culture methods through the demonstration sites in order to begin their own successful shellfish aquaculture ventures. The Beaufort demonstration site was harvested in December 2013 and the Charleston site will be harvested in the Spring of 2014. Data will be analyzed and reported, with project results, to growers.

RECAP: The South Carolina Sea Grant Consortium works with two prospective private sector clam farmers to demonstrate effects of production methods on product quality and business success.

Creating dialogue, and potential business partnerships, between tourism and aquaculture industries
PI: Julie Davis, S.C. Sea Grant Consortium

The nation has been experiencing a recent increase in interest in the local food movement. This includes informing people about the sources of their food. Agritourism is a growing sector of many farming businesses, and there is potential for it to become an additional income stream for local aquaculture businesses, and, more broadly, the seafood industry, as well. 

RESPONSE: With funding from a National Sea Grant Aquaculture Extension grant, the South Carolina Sea Grant Consortium’s Living Marine Resources Extension Specialist and Clemson University’s Bill Norman interviewed 30 people in Beaufort, McClellanville, and Mount Pleasant about the interactions of tourism and aquaculture. Aquaculture, in some cases, was expanded to include commercial seafood production depending on the prevalence of aquaculture in the community. Interviewees included shellfish farmers and wholesalers, festival organizers, chamber of commerce staff, visitor bureau staff, chefs and restaurateurs, eco-tour and watersports operators. Interviews lasted roughly 30-40 minutes. 

RESULTS: Talking about how farms operate piqued the interest of at least two eco-tour operators in offering a tour that would incorporate shellfish farming. One chef, who also operates a clam farm, expressed interest in being the last stop on the tour where people could eat his clams. In 2014, the project will continue with gathering information through a visitor intercept survey to determine how aquaculture fits into the visitor experience in these communities and in three communities in Florida.

RECAP: With education and facilitation by the South Carolina Sea Grant Consortium extension specialist and a research grantee, eco-tour operators, shellfish farmers, and chefs agree that there is an opportunity for incorporating aquaculture in local tourism and have planned to conduct a market analysis in the coming year.

Lowcountry Seafood a Highlight of the Chefs Collaborative Sustainable Food Summit – Rave Reviews and National Media Exposure Follow
PI: Julie Davis, S.C. Sea Grant Consortium

South Carolina’s seafood industry faces numerous challenges that demand producers get top dollar for their product. This is only possible when the product is of a high quality and the buyer is willing to think differently about the products being offered. Culinary trends often trickle down from top chefs so it’s wise to capitalize on any opportunity to engage these culinary leaders.

RESPONSE: The Consortium co-sponsored and participated in the 2013 Chefs Collaborative Sustainable Food Summit held in Charleston November 3-5, 2013. Over 200 of the country’s top chefs, writers, farmers, fishermen, federal fisheries and aquaculture representatives, and not-for-profit environmental groups were in attendance. To highlight South Carolina Seafood, the Consortium helped organize and co-host a field trip to an oyster farm in Beaufort, SC and a lunch highlighting locally produced seafood.

RESULTS: Thirty-five field trip participants enjoyed a boat tour of Lady’s Island Oyster Farm, including a hands-on activity regarding oyster hatchery and nursery production by the Consortium. Owners/operators of Beaufort Shellfish Company were on-hand preparing clams and mussels and educating people about their growing techniques. Participants sampled local seafood and a Lowcountry boil prepared on-site by Fleet Landing Restaurant, a South Carolina Sustainable Seafood Initiative platinum partner. To date, four articles in magazines with international distribution have been written about the trip, including one from renowned food author and oyster connoisseur Rowan Jacobsen.

RECAP: The South Carolina Sea Grant Consortium fostered partnerships between local seafood producers and America’s leading chefs at the 2013 Chefs Collaborative Sustainable Food Summit.

Equipping Growers with the Tools for Success –‘Aquaculture Business Management and Marketing’ Workshop Held in Charleston
PI: Julie Davis, S.C. Sea Grant Consortium

The success of any small business, especially farming, relies on a well-researched and executed business plan. Many prospective and start-up businesses lack access to the resources needed to compile a business plan. Established businesses may not be aware of the financial health of their business, thereby impacting their resilience. Small businesses also seek innovative examples on how to market their product, be it directly or through a distributor.

RESPONSE: The S.C. Sea Grant Consortium partnered with the National Aquaculture Association, South Carolina Department of Natural Resources and the South Carolina Shellfish Growers Association to present a half-day, interactive workshop to provide aquaculturists the knowledge and take-home tools they can use to assess the financial health of their businesses. With a focus on hard clams, the participants also learned about supermarket trends in marketing seafood and how they might employ innovative marketing strategies for their products.

RESULTS: Nineteen members of the aquaculture community, including clam and oyster farmers, soft-shell crab producers, fish farmers, and government representatives, participated in the workshop. Attendees increased their knowledge of business management and marketing. Ninety-four percent of participants felt the workshop was a good use of their time and they learned something new to apply in their business.

RECAP: Thanks to a South Carolina Sea Grant Consortium co-sponsored workshop, South Carolina aquaculturists are now better-equipped with knowledge to assess the financial health of their business and employ innovative marketing ideas.

Blue Crab Fishermen Collect Data to Identify Impacts of Changing Climate
PI: Julie Davis, S.C. Sea Grant Consortium

Beaufort County crabbers were impacted by several multi-year periods of drought beginning in 2002. This led crab fishermen to seek information about how their industry is and will be impacted by variability and change in climate. 

RESPONSE: The South Carolina Sea Grant Consortium (SCSGC), in partnership with the Social and Environmental Research Institute (Amherst, Massachusetts), conducted background interviews with eight crabbers in Beaufort County to gather their perspective on climate factors impacting the crab fishery. The crabbers, along with resource managers and scientists, were then invited to participate in Vulnerability, Consequences and Adaptation Planning Scenario (VCAPS) workshops that helped identify components of the fishery most affected by a changing climate. This work is part of a larger, NOAA-supported project examining the climate impacts on fisheries along the US Atlantic Coast.

RESULTS: Workshop participants agreed that crabber involvement in data collection would enhance fishery assessments and inform adaptive strategies. Three crabbers volunteered to become involved in monitoring the fishery, including collecting basic environmental data. In addition to informing future decisions, the data will help ground truth existing population-based, drought-response models. From this partnership and improved communication, fishermen, scientists and managers will continue to work together to develop adaption strategies that allow them to continue to land a high quality product. SCSGC, in cooperation with Clemson University and the South Carolina Department of Natural Resources, are coordinating the data collection effort with crabbers. 

RECAP: Beaufort County crabbers, working with the South Carolina Sea Grant Consortium and partners, identified data needs and plan to collect data necessary to develop a strategy for adapting to a changing and variable climate.

New Population Genetic Tool for Blue Crab Management Indicates a Healthy and Genetically Diverse Population in Charleston Harbor
PI: Tanya Darden, S.C. Department of Natural Resources

The Atlantic blue crab (Callinectes sapidus) supports valuable commercial and recreational fisheries. Both commercial and fishery-independent landings have shown a steady decline in blue crab abundance over the past decade, making C. sapidus a potential species of concern for fisheries managers. However, our understanding of blue crab biology is lacking is several areas, including offshore population composition (i.e. reproductive or senescent females), overwintering behavior, reproductive output of estuaries, recruitment bottlenecks and habitat limitations, and settlement cues.

RESPONSE: Sea Grant researchers at SCDNR investigated the development of molecular techniques to support the implementation of a responsible stock enhancement research program for blue crab that focuses on the use of cultured animals to address fundamental population ecology questions. The resultant information has potential to be directly useful for improving management decision-making. 

RESULTS: Investigators assembled and optimized six microsatellite markers for C. sapidus for use as non-lethal tags to identify hatchery-raised individuals. Using the suite of six microsatellite loci, a base-line genetic health characterization of blue crab in the Charleston Harbor System was completed. Initial results indicate that this population generally contains moderately high levels of genetic diversity and low levels of inbreeding. In addition, the effective population size is approximately a few thousand individuals, leading to the conclusion that this population is genetically healthy, despite recent declines in numbers.

RECAP: Researchers completed development of a genetic tool, in which genetic markers serve as permanent, non-lethal tags for identifying hatchery-raised blue crabs during and after stock enhancement. Results have already provided valuable information on blue crab ecology and life history that can be incorporated into fisheries management decisions.

Assessing the Hazards of Marine Plastic Debris to Shellfish Larvae
PI: John Weinstein, The Citade

Plastic debris represents one of the most pervasive and persistent pollution problems in the marine environment. Current evidence suggests that the presence of microplastic debris contributes to the decreased health and sustainability of estuarine species, however the toxicological consequences of the physical presence of microplastics in the feeding appendages and guts of larval invertebrates are largely unknown.
RESPONSE: A seed project was supported at The Citadel  to collect preliminary data concerning the prevalence of macro-and microplastic debris in Charleston Harbor and to begin to assess the innate toxicity of microplastic debris on the larval forms of two ecologically important estuarine species, hard clams (Mercenaria mercenaria) and grass shrimp (Palaemonetes pugio). Sea Grant researchers collected, sorted, counted, and weighed all plastic debris items collected by Beach Sweep/River Sweep volunteers at eight locations around Charleston Harbor. A total of almost 200 pounds of material was examined. Investigators then initiated toxicity testing, though due to inconsistent availability of larval oysters, juvenile hard clams were substituted as the model bivalve. . Mechanical toxicity tests were conducted on grass shrimp larvae by exposing them to five sizes of microspheres at a concentration of 20,000 microspheres/400 mL over three hours, with control shrimp in microsphere-free water. Developmental toxicity was tested by exposing the larvae to 32 and 150 µm microspheres over 21 days, and measuring weights and transformation times. Finally, pollutant transference to tissues was tested in adult grass shrimp through three-hour exposure to fluoranthene-coated polyethylene microspheres.

RESULTS: A total of 3,646 plastic items were counted across all sites with a total weight of 195.3 pounds. Polypropylene and polystyrene were collected in statistically higher numbers than other plastic items, comprising 54% of total plastic debris measured, and included plastic food storage containers, bottle caps, and Styrofoam containers. Sediment samples indicated that most microplastics were found around the high tide line. Toxicity tests demonstrated that shrimp exposed to 83 µm microspheres demonstrated the highest mortality at 40%, with both larger and smaller particles leading to mortality rates from 0-25%. Any shrimp surviving 96 hours post-exposure were able to expel the microspheres from the gills and gut. In the developmental tests, weight was not significantly impacted by exposure, however transformation times decreased by almost two days in each microsphere class.

RECAP: Results from a research seed project suggest that the presence of microplastics in the estuarine environment has the potential to alter larval grass shrimp development and facilitate the transfer of persistent organic pollutants (POPs) to adult grass shrimp tissues, while also impacting the ability of the larvae to depurate the microspheres from their gills and gut.

Innovative Consortium Research Highlights Role of Gene Groups in Egg Quality and Embryo Development
PI: Robert Chapman, S.C. Department of Natural Resources

The inability of eggs to produce viable embryos is considered a major limiting factor for development of global finfish aquaculture, and has remained intractable and of unknown cause(s) despite decades of attention by researchers around the world. Recent research has strongly implicated dysfunction of ovarian gene expression as a root cause of the problem. Consortium researchers hope to discover patterns of ovarian gene expression associated with high and low egg quality in striped bass, a finfish used in aquaculture that has problems with arrested development in eggs. These patterns could identify the specific physiological functions that are impaired and point the way toward changes in husbandry practices that can optimize egg quality.

RESPONSE: The goal was to discover patterns of ovarian gene expression associated with high and low egg quality in stocked striped bass which identified specific physiological functions that were impaired, and lead to changes in husbandry practices that can optimize egg quality. Further, the researchers hoped to extend the analysis to wild caught individuals and evaluate the capacity of gene expression profiling as a tool for assessing the egg quality among age cohorts. 

RESULTS: Results demonstrate that interactions among a small group of genes influence egg quality, a key part of reproductive fitness in all vertebrates including humans. These findings may help aquaculturists select fish that have the highest probability of producing large numbers of viable eggs. Additionally, fisheries managers may be able to better evaluate what percentage of females in the wild population is going to produce viable eggs and subsequently modify management strategies.

RECAP: Research demonstrating that a small group of genes influence egg quality in target fisheries species, and therefore embryo development, has the potential to help aquaculturists select fish with the highest likelihood of producing viable eggs, and will have major impacts on finfish aquaculture worldwide.

Consortium Research Develops A Novel Tool to Enhance Fishery Management of Commercially-Important Finfish Species
PI: Dianne Greenfield, S.C. Department of Natural Resources

Indices of fish egg production are essential for understanding recruitment and developing stock assessment models for species management. Traditional methods of enumerating and identifying planktonic fish eggs entail time-consuming microscopy. Furthermore, eggs of different species are often morphologically indistinguishable, leading to erroneous population assessments that affect management decisions.

RESPONSE: Sea Grant researchers addressed this problem by seeking to develop and validate a rapid, cost-efficient, and novel molecular tool that facilitates species-specific fish egg identification and quantification using the economically important species red drum as the target organism. During the effort to design the species-specific egg identification tool, specific rRNA regions of interest from the target species and eight closely related species were compared.

RESULTS: Researchers discovered that there was little interspecific genetic difference between the fish, so a species-specific capture probe could not be developed from that particular rRNA region. To overcome this, a more versatile genome was sequenced, and this revealed several regions that were distinct and therefore promising candidates for probe design. Additionally, researchers designed both new capture and signal probes for the sequenced genome region. A private industry partner, Spyglass Technologies, will produce the assays as a commercially-available product for end-users to enhance fishery management. The company recognizes the relevance of this application to both the management and recreational fishery sectors.

RECAP: Consortium-sponsored research led to development of a new molecular tool enabling better understanding of red drum reproduction and life history, and fostering better-informed fishery management; this tool is under discussion for possible commercial production by the private sector.

Consortium Supports Development of Economically Competitive and Environmentally Responsible Mariculture
PI: John Leffler, S.C. Department of Natural Resources

A robust aquaculture industry is needed nationwide to meet rising demands for safe and healthy seafood, but must be developed in a way to minimize its impacts on the natural environment. A national conference convened in 2008 concluded that to become economically competitive and environmentally responsible in mariculture, the United States would have to rely on innovative technology as its major strength and focus.

RESPONSE: Consortium researchers are examining a minimal-exchange biofloc -based system for use in the development of an environmentally friendly, economically competitive, indoor polyculture system to grow high value crops of fish, shrimp, and oysters. Biofloc, an aggregate feed source, is easily digestible and nutritious. Four biofloc systems were developed and tested, using varying combinations of shrimp, oyster, red drum, and tilapia stock.

RESULTS: Originally stocked with oysters, shrimp, and red drum, the systems developed intense HABs. Tilapia were incorporated into two of the systems to control harmful algal blooms (HABs) and solids accumulation. Survival rates of the stock were very high, ranging from 96-100%, and after conclusion of the trial in March 2014, local chefs and seafood distributors will evaluate the food quality of the product and estimate market prices.

RECAP: Consortium-supported research into biofloc-based, recirculating polyculture systems has the potential to facilitate an important diversification of mariculture products that can be grown year-round with low environmental impacts and in inland areas adjacent to profitable markets that value fresh, year-round seafood.

Last updated: 9/28/2015 11:35:15 AM
FY13-14 – Sustainable Fisheries and Aquaculture


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