Progress 08/15/10 to 08/14/13
Outputs
Target Audience: Clam aquaculture industry members, including hatchery operators, growers, and wholesalers, in Florida were the targeted audience and were actively engaged in the project. Their voluntary actions reflected the commitment of the industry in assisting applied research efforts to enhance hard clam production by improving heat-resistance in clams,determining genetic diversity in clam stocks, assessing soil properties on shellfish aquaculture leases, and investigating alternative bivalve species for culture. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? Awareness of the need for a hardier clam strain through genetic improvement to meet increasing national demand for aquaculture products resulted in the Cedar Key Aquaculture Association taking a leadership role in procuring federal research funding (USDA-NIFA)to supportapplied research projects.This supportallowed for development of a research and extension project team whobegan to address the industry’s needs.Further, this support has allowed the project team to solicit competitive grant funding.An integrated partnership among the clam farming community, research and extension faculty has been developed.The partnershipfocuses and leverages available resources to enable the sustainable development of molluscan shellfish aquaculture in Florida. The followingvoluntary actions of industry members in this projectreflected the commitment of the industry in assisting applied research efforts. To represent hatchery stocks in the genetic diversity evaluation of hard clams, samples of stocks were obtained from six (anonymous) commercial hatcheries in Florida.Florida clam growers also had a specific role in assisting in site selection and access to their leases forsoil sampling. The results benefited them by giving them direct knowledge of their leases, while this knowledgewasapplicable to other growing areas as well.Seed ark clams (over 100K) were transferred tofourcommercial clam culturists for continued culture and evaluation in their systems. How have the results been disseminated to communities of interest? Hatchery operators, land-based nursery operators, growers and wholesalers were engaged in various aspects of this research, thereby allowing for technology transfer to each of these shellfish aquaculture industry sectors.Results of thisproject were also disseminated to the aquaculture industry in the form of several deliverables. Summaries highlighting the progress of this project were provided in the UF Cooperative Extension Service newsletter, The Bivalve Bulletin.Investigators attended the Clam Industry Workshop, held annually in Cedar Key, and provided progress reports on the various components of this project directly to industry members. These workshops provided a forum for discussion and feed back with the industry. Abstracts of workshop presentationswere posted on the Florida Shellfish Aquaculture Online Resource Guide website (http://shellfish.ifas.ufl.edu). Workshops on hatchery methods for maintaining genetic diversity were held on the east coast (HBOI-FAU) and west coast (Cedar Key) of Florida in which commercial seed suppliers were introduced to proper genetic development and maintenance protocols of bivalve broodstock for seed production. The project team also presented results of this work at regional and state meetings (e.g., Florida Indian River Lagoon Symposium, Florida Marine Biology Symposium), as well as atprofessional meetings (e.g., National Shellfisheries Association, World Aquaculture Society). Industry, agency, academic, and extension representatives attended these meetings and were introduced to the project’s findings. Results will also be published in a professional, peer-reviewed journal (Journal of Shellfish Research). What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Hard Clam Broodstock Development: Selective breeding practices associated with large-scale hatchery production of hard clams, Mercenaria mercenaria, may result in unintended, negative consequences, such as inbreeding and reduced levels of genetic diversity. Seven microsatellite markers were used to compare levels of genetic diversity in six strains of cultured clams produced in Florida commercial hatcheries and in clams collected from natural assemblages along the Florida east coast at four sites where “wild” harvesting is known to exist. Wild stocks of M. mercenaria displayed a greater number of alleles (NA=9.28) and higher levels of allelic richness (AR=3.34) relative to hatchery-produced individuals (NA=8.14, AR=3.18). Differentiation was highest among hatchery stocks (GST=0.018, P<0.001), and similar among hatchery+wild comparisons. In contrast, panmixia could not be rejected among wild stocks based on differentiation measures (GST=-0.002, P=0.58), and Bayesian model comparisons of panmixia, stepping stone, and full-migration gene flow models. Null alleles were frequent, and attempts to amplify a congeneric species, M. campechiensis, using the same suite of microsatellite markers were largely unsuccessful at five of the seven loci. Drift has occurred within Florida hatchery populations though the divergence between wild and hatchery hard clam stocks are not yet at the scale seen in some other aquacultured bivalve species. Hatchery production of hard clams is done in such a manner that differences in genetic diversity and differentiation between wild and aquaculture stocks are limited. As aquaculture production of hard clams expands, maintaining genetic diversity in cultured stocks via broodstock selection techniques will be important in order to limit potential deleterious effects associated with mass production of seed from few, related individuals. Microsatellite markers may be unsuitable for future studies aimed at detecting intraspecific hybridization and microsatellite loci should be identified de novo for different species of Mercenaria. Improved Harvest Practices: Sampling of bottom sediments during the summer (2102) at a commercial lease area, consisting of 110 two-acre parcels on Florida’s west coast, was repeated for winter (2013) to discern seasonal effects, and further develop relationships between soil characteristics and subaqueous landscapes associated with intensive hard clam farming (planting and harvesting) activities. Soil cores collected at three individual lease parcels were analyzed for bulk density, organic matter content, and particle size distribution. The winter sampling at a commercial hard clam lease area produced mixed results. Soils at one lease parcel were different from easement (unfarmed) soils; this agreed with prior summer results. This lease parcelhad a moderate amount of organic matter and fines. Soils at a second lease were different while the summer results showed none. At a third lease parcel, both summer and winter showed no differences. Thus, we cannot conclude that season is an important factor in determining soil variability. Collectively, these results suggest that farming intensity, season, and natural soil properties have little or no effect on aqueous soil properties. Combined with relatively short return times from the harvesting study, we conclude that clam farmers do not need to drastically alter planting schedules or other activities in an effort to protect soils. Simply observing a fallow time of 1-2 months will likely ensure that soils remain in their pre-farmed state as they are farmed. It is possible that external environmental factors could impose a difference between farmed and unfarmed areas, but this study did not investigate that.Sampling of bottom sediments during the summer (2102) at a commercial lease area, consisting of 110 two-acre parcels on Florida’s west coast, was repeated for winter (2013) to discern seasonal effects, and further develop relationships between soil characteristics and subaqueous landscapes associated with intensive hard clam farming (planting and harvesting) activities. Soil cores collected at three individual lease parcels were analyzed for bulk density, organic matter content, and particle size distribution.Sampling of bottom sediments during the summer (2102) at a commercial lease area, consisting of 110 two-acre parcels on Florida’s west coast, was repeated for winter (2013) to discern seasonal effects, and further develop relationships between soil characteristics and subaqueous landscapes associated with intensive hard clam farming (planting and harvesting) activities. Soil cores collected at three individual lease parcels were analyzed for bulk density, organic matter content, and particle size distribution. Species Diversification: The ponderous ark clam Noetia ponderosa has been considered a potential aquaculture species in Florida. Previous research indicated a bottleneck at metamorphosis when using traditional hard clam Mercenaria culture techniques.It was proposed that settlement cues might be necessary for this species.Arks collected from natural populations on Florida’s west coast were provided to HBOI-FAU for maturation and spawning efforts. Arks spawned spontaneously and repeatedly (5 times in 2013) in conditioning tanks (20-22oC) and viable larvae were obtained from most of these spawns. Larvae were cultured similarly to clam larvae being fed microalgae daily along with daily water changes. Larvae reached setting size (220um shell length) primarily at day 14-16. A series of trials were conducted in which N. ponderosa larvaeobtained from volitional spawns were exposed to different settlement conditions from that used in traditional hard clam culture.One trial used downwellers with combinations of sand substrate and flocculated algae. After 30 days, no larvae or metamorphosed juveniles were found, but differences noted in shell length of dead organisms indicated that flocculated microalgae might assist in setting.Further trials examined settlement on tank bottoms, as done with other bivalves.Size-competent ark clam larvae from three separate spawns were placed in rectangular tanks (400L) to which were added pieces of macroalgae Ulva, benthic diatom assemblage Amphora, or natural silt.No water changes were done, but microalgae were added intermittently. After 16-30 days, metamorphosed larvae were found attached to the Ulva and on tank bottoms in all treatments, suggesting that bare tanks bottoms were acceptable and no additions were needed.The settlement of ponderous arks from the first tank-bottom trial yielded about 100K juveniles (>1.2 mm), which was about a 36% return from the number of competent larvae added to thetanks; larvae survival from day 2 to 16 was 2.2%.Juveniles were land-based nursed using standard methods, resulting in 64K arks (9mm SL) holding on a 5.0 mm screen within 5-7 weeks. Strong byssal threads did not hinder sieving of arks. Two other spawns further examined if settlement cues were necessary but no differences were found in all treatments and controls. These produced about a 10% return. Larval survival from day 2 to placement in tanks was near 50% for both groups. Although settlement and metamorphosis was achieved, further examination is needed for mass production of ponderous arks to be used for commercial culture as none of the treatments produced consistently more set as compared to the controls.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
Scarpa, J., Baker, S.M., Sturmer, L.N. and Krebs, W. 2013. Preparing for Climate Change: Increasing Hard Clam Survival in Florida Using Biomarkers of Thermal Tolerance. Aquaculture 2013, Nashville, TN, 21-25 February 2013. Book of Abstracts, p 995.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
Scarpa, J., Baker, S.M, and Sturmer, L.N. 2013. Climate Change Issues for Clam Aquaculture in the Indian River Lagoon. 2013 Indian River Lagoon Symposium, Ft. Pierce, FL, 7 February 2013. Book of Abstracts, p 18.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
Baker, S.M., Sturmer, L.N. and Scarpa, J. 2013. Breeding a Better Clam: Preparing the Florida Hard Clam Aquaculture Industry for Climate Change. University of Florida Marine Biology Symposium, Whitney Laboratory for Marine Bioscience, Marineland, FL, 17-18 January 2013. Abstract Booklet, p 4.
- Type:
Journal Articles
Status:
Other
Year Published:
2014
Citation:
Hargrove, J.S., Sturmer, L., Scarpa, J., and Austin, J.D. 2013. Genetic Diversity in Wild and Aquaculture Populations of the Hard Clam Mercenaria mercenaria in Florida. In preparation.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
Sturmer, L., Adams, C., Baker, S., Ellis, R., Osborne, T., Otwell, S. and Scarpa, J. 2013. Florida hard clam aquaculture: From business development to a sustainable industry. Sustaining Economics and Natural Resources in a Changing World: Key Role of Land Grant Universities, Symposium Poster Abstracts.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2014
Citation:
Sturmer, L.N., Scarpa, J., White, W. and Baker, S. 2014. Improving hard clam production in Florida through thermal selection of broodstock. To be presented at the annual conference of the National Shellfisheries Association, 29 Mar-2 Apr, 2014, Jacksonville, FL and to be published in the Journal of Shellfish Research.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2014
Citation:
Scarpa, J. and Sturmer, L.N., 2014. Successful larvae settlement and hatchery culture of the ponderous ark clam Noetia ponderosa. To be presented at the annual conference of the National Shellfisheries Association, 29 Mar-2 Apr, 2014, Jacksonville, FL and to be published in the Journal of Shellfish Research.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2014
Citation:
White, W., Sturmer, L.N., Ellis, L.R., and Osborne, T. 2014. Applying a soils-based approach to clam aquaculture in Florida. To be presented at the annual conference of the National Shellfisheries Association, 29 Mar-2 Apr, 2014, Jacksonville, FL and to be published in the Journal of Shellfish Research.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2014
Citation:
Austin, J.D., Hargrove, J.S., Sturmer, L., and Scarpa, J. 2014. Genetics of hatchery and wild clams: What, if anything, can we learn from microsatellite loci. To be presented at the annual conference of the National Shellfisheries Association, 29 Mar-2 Apr, 2014, Jacksonville, FL and to be published in the Journal of Shellfish Research.
|
Progress 08/15/11 to 08/14/12
Outputs
OUTPUTS: Samples of 40-50 hard clams obtained from natural populations in four Florida east coast counties and from seven Florida commercial hatcheries were analyzed for heat shock protein (Hsp) 70 levels by Dr. Scarpa at HBOI-FAU. Tissue samples (adductor muscle) of individual hard clams from these cultured and wild groups were preserved and shipped to Dr. Austin's laboratory for DNA extraction, PCR amplification, and microsatellite analysis. Data analysis is ongoing. To understand the temporal and spatial effects of farming intensity on soil properties, sub-aqueous soil cores (n=61) were collected within and adjacent (unfarmed) to three shellfish aquaculture leases located within the Dog Island High-density Lease Area (HDLA) during the winter (2011). During the summer (2012), another 60 samples were collected at six leases within a different growing area (Gulf Jackson HDLA). To determine physical and chemical changes to soils due to harvest disturbance, cores (n=6), as well as soil elevation readings (n=12), were collected immediately after harvest and after varying fallow times (2, 4, and 8 weeks post-harvest) from three of these leases. Winter (2013) sampling is scheduled at these farm sites to discern seasonal effects, and further develop relationships between soil characteristics and subaqueous landscapes associated with intensive clam farming (planting and harvesting) activities. Soil cores were analyzed for redox potential, hydrogen sulfide concentration, bulk density, organic matter content, and particle size distribution. Ponderous ark clams collected from natural populations on Florida's west coast were provided to HBOI-FAU for final maturation and spawning efforts. Arks spawned spontaneously and repeatedly in conditioning tanks (20C); however, larvae were not viable in two of the three instances. Blood plasma samples were collected from 110 white seabass and sent to California State University Long Beach (CSULB) for radioimmunoassay testing of cortisol level. Samples included 30 fish from recirculating systems inside the hatchery, 30 fish from outside flow thru raceways, and 20 fish each from two coastal pen sites. Another 30 fish were sampled from a manipulative study on temperature. A serial sampling trial was completed and a density trial is being planned. Pituitary cDNA libraries were created to determine the gene sequence for common snook and the genes involved in the neuroendocrine control of fish reproduction were cloned and sequenced. This information will enable us to compare wild and captive endocrine profiles and identify potential deficiencies in captive broodstock. Understanding how reproduction is entrained through environmental cues and the pathways leading to oocyte recruitment and maturation is essential. PARTICIPANTS: Leslie Sturmer is responsible for overseeing the University of Florida (UF) components of this project. One technician and a biological scientist, partially paid from the grant, are responsible for collecting clam stocks and soil samples. Jim Austin and his doctoral student (UF Wildlife Ecology and Conservation) are responsible for genetic analysis of clam stocks. Denise Petty (UF College of Veterinary Medicine) oversees the health survey of clam stocks. Rex Ellis and Todd Osborne (UF Soil and Water Science) both lead in the experimental design of the soil studies and analyses. John Scarpa with Harbor Branch Oceanographic Institute at Florida Atlantic University (HBOI-FAU) was subcontracted to conduct the hard clam Hsp analysis and ark clam larval rearing and setting experiments; paid by grant. Vincent Encomio with Florida Oceanographic Society serves as an advisor to Scarpa with hard clam Hsp analysis; paid by HBOI-FAU subcontract. Hubbs-SeaWorld Research Institute; California State University Long Beach,Mote Marine Aquaculture Research Scientific Staff, Dr. Herve Migaud (University of Stirling), Drs. Yonathan Zohar and Nilli Zmora (University of Maryland, Baltimore, MD). TARGET AUDIENCES: Clam aquaculture industry members, including hatchery operators, growers, and wholesalers, in Florida are the targeted audience and are actively engaged in the project. Their voluntary actions reflect the commitment of the industry in assisting applied research efforts to enhance hard clam production by improving heat-resistance in clams, assessing soil properties on shellfish leases, and investigating alternative bivalve species for culture. Aquaculture Industry and Research Community PROJECT MODIFICATIONS: Seven microsatellite primers were screened on 16 hard clams (Mercenaria mercenaria, MM) and 16 southern quahogs (M. campechiensis, MC) from an initial screen of 14 loci developed through the Genomics Division of the Interdisciplinary Center for Biotechnology Research (ICBR) at UF. Half of these amplified poorly, had excessive stutter, or otherwise were deemed to be worth setting aside. From the 7 retained loci, 5 primer pairs appeared to display some degree of size separation by species (i.e., some alleles were present in higher proportions in one species and were either not present or present in lower proportions in the other population). In general, amplification was more successful in MM than for MC. Three panels were established for the 7 markers, 2 containing 3 msats and one containing only an individual marker. These will be used for screening diversity in wild and hatchery clam strains. Given that microsatellites are bi-parentally inherited, a mitochondrial marker was desired in order to assess the matrilineal species (potential to discern directionality of cross in first generation). In other words through sequencing the cytochrome oxidase I gene, we would be able to tell if a given clam had a mother of either MM or MC lineage. Eight samples, 4 from each species, were amplified and sequenced. Based on simple p-distance calculations (a metric for inter and intraspecific variation), the genetic distance between the species is 10.175%, while the amount of variation within a species is closer to 0.004% (MC). Future work should consider the addition of more microsatellites to reach a final panel of markers that are easily scored and amplified but that give a reasonable genome-wide picture of diversity. Of the 5 markers that have currently been selected, one has a tri-allelic display that is of concern (we know that Mercenaria possess duplicated genes which could likely explain this observation), and 3 markers are difficult to successfully amplify in both species. Thus, we will not be able to determine species parentage of samples using microsatellite markers for assessing if pure MM stocks exist in Florida for future breeding efforts. We reduced the number of manipulative cortisol experiments to focus on better understanding patterns of cortisol release after stress events (e.g. time series). We also focused extensive effort on developing papers for publication.
Impacts
Heat shock protein (Hsp) 70 levels from cultured and wild groups of hard clams varied within and between groups; size or age may be a factor. There was a 4-fold difference between "high" and "low" expressing groups, which will allow for attempted breeding to examine if cognate Hsp 70 is heritable. Genetic analysis of these clam groups using microsatellite markers will allow us to compare genetic diversity between natural (wild) and cultured hard clam stocks. A correlation analysis of diversity data to Hsp levels will be performed to assist in marker-assisted selection. Species parentage of these groups will not be assigned using microsatellite markers due to problems encountered (see Project Modifications). Soil properties measured at intensively-farmed leases and adjacent easements (unfarmed areas) were not statistically different, indicating that effects of clam culture may be nominal. Leases and easements are subjected to similar environmental conditions (e.g., tides, currents, winds), which may have more of an influence on soils than farming activities. Long-term effects of intensive bottom planting may be small compared to the natural variability that exists in aqueous soils. Soil properties of harvest sites typically converged with adjacent reference (unfarmed) sites after a few weeks. For harvest sites located at the Dog Island HDLA, ave recovery time of soil properties was 2.9 weeks with a max of 4 weeks. At the Gulf Jackson HDLA, ave recovery time was 5.7 weeks with a max of 8 weeks. Recovery times were longer for these leases possible due to greater sand (97%) and lower fine (clay+silt=3.3%) content than soils at the Dog Island HDLA (91% sand, 8.6% fines). Based on these findings, it is recommended that growers periodically observe a brief (e.g., 2-8 weeks) fallow period between plantings in order to avoid long-term changes to soil properties. Understanding these soil relationships is critical to increasing productivity, directing management practices, and selecting lease sites. For one ponderous ark spawn, 12% were brought through the larval phase in 21 days reaching about 225um in length. A setting experiment using downwellers was conducted with combinations of sand substrate+flocculated algae. Larvae fed microalgae settled, then died during the 30-day study. Shell lengths for control (microlgae+no substrate) were 230um, flocculated microalgae+no substrate were 350 um, and flocculated microalgae+substrate were 330um. From this limited data flocculated microlgae may assist in "setting" of ponderous arks, but a different system needs to be tested for further nursery culture. We documented variability in cortisol levels among fish taken from different rearing systems and found significant variability among types of rearing units, within those rearing units, and among fish within the same rearing unit. Serial sampling after a 30 second exposure to air resulted in a peak of cortisol from 50 to 400ng/ml. The peak did not return to baseline within the sampling period of 72 hours. Results from these trials will provide new tools to improve reproductive performance of captive marine fish broodstock populations.
Publications
- White, W., Sturmer, L.N., Ellis, L.R., and Osborne, T. 2012. Applying a soils-based approach to clam aquaculture in Florida. J. Shellfish Res., 31(1):360.
- Lloreda, L., Krebs, W., Scarpa, J., Sturmer, L.N. and Baker, S.M. 2012. Helping the Florida clam industry survive the summer. National Shellfisheries Association 104th Annual Meeting, Seattle, WA, 25-29 March 2012. J. Shellfish Res., 31(1): 314. Sturmer, L.N., Scarpa, J. and White, W. 2012. Florida hard clam breeding projects: results of growout trials. Clam Culture Industry Workshop, Cedar Key, Florida, 7 November 2012, Summary of Presentations: pp.10-11 (http://shellfish.ifas.ufl.edu/industry_workshops.html).
- Ellis, L.R., Osborne, T., White, W., and Sturmer, L.N. 2012. Applying a soils-based approach to clam aquaculture in Florida. Clam Culture Industry Workshop, Cedar Key, Florida, 7 November 2012, Summary of Presentations: pp. 6-7 (http://shellfish.ifas.ufl.edu/industry_workshops/html).
- Sturmer, L. 2011. Research Updates: Examining relationships between clam farming activities and aqueous soils properties. The Bivalve Bulletin: XV(2):5 (http://shellfish.ifas.ufl.edu/newsletters/html).
- Rhody, N.R., C. Puchulutegui, K.L. Main, and H. Migaud. 2012. Analysis of parental contribution and spawning performance in wild captive common snook Centropomus undecimalis broodstock, Aquaculture 2012, September 1-5, 2012, Prague, Czech Republic.
|
Progress 08/15/10 to 08/14/11
Outputs
OUTPUTS: Endocrine profiles for captive snook broodstock were characterized from monthly blood plasma samples and compared with previous work conducted with wild fish. To determine the efficacy of the environmental and hormonal therapies, molecular analysis included radioimmunoassay used to detect a range of sex steroids. Female blood samples were evaluated for levels of 17β-estradiol and female testosterone and male blood samples were evaluated for levels of testosterone and 11-ketotestosterone. Results are still being analyzed and will be reported in the next reporting period.Eleven groups of hard clams were collected from natural and commercially cultured stocks, their health status determined, cognate heat shock protein 70 (cHsp70) assessed, and tissue samples taken for genetic analysis using microsatellites. Individual clams (50/group) were assessed for cHsp70 by ELISA (50/group) and grossly and histologically examined (10/group) for health. To understand the effects of farming practices on soil properties, sub-aqueous soil cores (116) were collected within and adjacent to 7 clam leases during the summer. Cores (24) were also collected, as well as elevation readings (24), immediately after harvest and at 1, 2, 4 and 8 weeks post-harvest from 2 leases. Ponderous ark clams were collected and have been cultured for use as broodstock in upcoming spawning trials. Blood plasma samples were collected from 110 white seabass and sent to California State University Long Beach (CSULB) for radioimmunoassay testing of cortisol level. Samples included 30 fish from recirculating systems inside the hatchery, 30 fish from outside flow thru raceways, and 20 fish each from two coastal pen sites. Another 30 fish were sampled from a manipulative study on temperature. Plans are underway to complete a serial sampling trial and density trial lasting 60 days. PARTICIPANTS: Mote Marine Aquaculture Research Scientific Staff, Dr. Herve Migaud (University of Stirling) Leslie Sturmer is responsible for overseeing the UF components of this project. One technician and a biological scientist, partially paid from the grant, are responsible for collecting clam stocks and soil samples. Denise Petty oversees the health survey of clam stocks. Rex Ellis and Todd Osborne both lead in the experimental design of the soil studies and analyses. John Scarpa with Harbor Branch Oceanographic Institute at Florida Atlantic University (HBOI-FAU) was subcontracted to conduct the hard clam Hsp analysis and ark clam larval rearing and setting experiments; paid by grant. Vincent Encomio with Florida Oceanographic Society serves as an advisor to Scarpa with hard clam Hsp analysis; paid by HBOI-FAU subcontract. TARGET AUDIENCES: Clam aquaculture industry members, including hatchery operators, growers, and wholesalers, in Florida are the targeted audience and are actively engaged in the project. Their voluntary actions reflect the commitment of the industry in assisting applied research efforts to enhance hard clam production by improving heat-resistance in clams, assessing soil properties on shellfish leases, and investigating alternative bivalve species for culture. Aquaculture Industry and Research Community PROJECT MODIFICATIONS: The initial Hsp70 measurements of hard clam stocks were delayed. These activities required the use of HBOI facilities, which were completely renovated in 2010, and took far longer than expected. Nonetheless, these activities have been initiated. However, maturation and spawning trials for the ponderous ark projected for the fall of 2010 could not take place and are scheduled for the fall of 2011.
Impacts
Results from these trials will provide new tools to improve reproductive performance of captive marine fish broodstock populations.Variation in cHsp70 variation was detected in all clam assemblages with a difference of approximately four times between lowest and highest average relative values. High and low cHsp70 broodstock were selected and spawned to create six families for comparison of cHsp70 in progeny. There were no differences between the health of wild and cultured clams, nor were any pathogens observed. Soil and data analyses are ongoing. However, no significant differences in spatio-temporal variability for soil chemical properties, such as ORP and H2S, are observed. Winter sampling is scheduled at the same farm sites to discern seasonal effects, and further develop relationships between soil characteristics and subaqueous landscapes associated with intensive clam farming practices. We are awaiting the results from the first samples sent to CLULB. This study represents the first step in the development of a comprehensive fish stress assessment program at HSWRI.
Publications
- Rhody, N.R., K.L. Main, and H. Migaud. 2011. Evaluation of spawning performance in wild captive common snook Centropomus undecimalis broodstock, Aquaculture America 2011, February 28-March 3, 2011, New Orleans, LA.
- Scarpa, J., Baker, S.M., and Sturmer, L.N. 2011. Preparing Florida hard clam, Mercenaria mercenaria, culture for climate change. Page 25 of abstract book, 14th International Conference on Shellfish Restoration (ICSR 11), Stirling, Scotland, 23-27 August 2011 (www.aqua.stir.ac.uk/shellfish2011/programme).
- Baker, S.M., Scarpa, J., and Sturmer, L.N. 2011. Selection for heat tolerance in hard clams using biomarkers. Page 11 of Summary of Presentations, Annual Clam Industry Workshop, Cedar Key, Florida, 2 February 2011(http://shellfish.ifas.ufl.edu/industry_workshops).
- Ellis, L.R. and Osborne, T. 2011. Examining relationships between hard clam farming activities and aqueous soil properties. Pages 15-6 in Summary of Presentations, Annual Clam Industry Workshop, Cedar Key, Florida, 2 February 2011 (http://shellfish.ifas.ufl.edu/industry_workshops).
- Ellis, L, T. Osborne, W. White., and L. Sturmer. 201_. Evaluation of clam farming intensity on subaqueous soil properties. Journal of Aquaculture. In progress.
- Ellis, L, T. Osborne., W. White., and L. Sturmer. 201_. Subaqueous Soil and Landform Relationships near Cedar Key, FL. Journal of Aquaculture. In progress.
|