Current aquaculture research activities by faculty and adjunct faculty at the Aquaculture Research Station, with support from research associates, graduate students and undergraduate student workers, are summarized below. Aquaculture research activities by faculty and staff in other administrative units in the LSU AgCenter and LSU main campus are not listed.
Dr. Robert Reigh, Professor and Interim Resident Director
Project 1: Comparison of the Utilization Efficiency by Channel Catfish of Dietary Amino Acids Provided in the Form of Intact Protein or As Purified Dietary Supplements. Objective: Quantify differences in the utilization of amino acids from intact protein and amino acids provided in crystalline form in channel catfish diets by (1) measuring and comparing the apparent availability of amino acids in six common feed ingredients with apparent amino acid availability of crystalline amino acids in mixtures designed to match the concentrations of amino acids in each of the feed ingredients, and (2) measuring differences in the rates of uptake of amino acids into the hepatic portal vein blood of channel catfish fed intact protein or crystalline amino acid mixtures.
Project 2: Determination of the Optimal Dietary Level of Microbial Phytase for Production of Pond-Raised Channel Catfish Fed an All-Plant Diet. Objective: Determine the effects of two levels of dietary phytase, 500 units/kg diet and 1000 units/kg diet, on production yields, body composition and dietary nutrient utilization of pond-raised channel catfish fed an all-plant diet with and without macro-mineral and trace mineral supplements. (Support: USDA Special Grant - Aquaculture)
Project 3: Effects of a Diet Supplemented with Ractopamine Hydrochloride on Availability of Dietary Amino Acids, Nitrogen Retention, and Dressed Yield of Channel Catfish. Objective: Determine the effects of ractopamine hydrochloride on utilization of dietary essential and non-essential amino acids; dietary protein utilization; and weight gain, dressed yield and body composition of channel catfish. (Support: USDA Special Grant - Aquaculture)
Project 4: Effects a High-DHA Algal Extract on Growth, Lipid Content and Fatty Acid Composition of Channel Catfish. Objective: Determine the efficacy of using a commercial algal extract with a high concentration of docosahexaenoic acid (DHA, 22:6n-3) as a dietary additive to increase the omega-3 fatty acid content of channel catfish muscle in a manner that will allow high omeg-3 catfish to be produced as a functional food. (In cooperation with Pennington Biomedical Research Center.)
Project 5: Measurement of Nutrient Availability in Feedstuffs for Florida Pompano, Trachinotus carolinus, and Development of Formulated Diets for Pompano Aquaculture. Objectives: (1) Determine the nutritional value for pompano of common feedstuffs used in animal feeds and begin producing a comprehensive database of nutrient availability information that will allow nutritionally complete diets for pompano to be formulated on a least-cost basis; and (2) measure the effects of different diet formulations on pompano growth and body composition in order to identify characteristics of the diet that maximize production yield and minimize feed cost. (Support: La. Sea Grant)
Dr. Robert Romaire, Professor
Project 1: Development and Refinement of Harvesting Strategies to Maximize Crawfish Aquaculture Profitability (with Dr. Ray McClain; Support: USDA Special Grant - Aquaculture). Because harvesting is the highest operating cost (50-70%) for crawfish producers, and bait alone accounts for 30-40% of the cost, research efforts are underway to increase harvest efficiency and reduce costs. Different trap densities, trap soak times and trap mesh configurations are being tested to ascertain their effects on total yield, catch per unit effort, crawfish harvest size and estimated profits. Efforts are also underway to evaluate various bait components, formulations and processing effects on bait efficacy for cooler water temperatures (< 60 oF).
Project 2: Improving Stream Water Quality in Southern Louisiana by Reducing the Impact of Crawfish Aquacultural Effluents Through Implementation of Best Management Practices (Support: Louisiana Department of Environmental Quality). The crawfish component of this multi-species regional project is aimed at addressing the gaps in information that exists regarding the influence of crawfish pond effluents on receiving waters and will facilitate the compilation of information regarding crawfish pond effluents into Best Management Practices (BMPs). Determination of water use patterns in crawfish production is a key element of this project that relates to effluent issues and development of BMPs.
Project 3: Interaction of White River Crawfish and Red Swamp Crawfish in Mesocosms. (with graduate student, William Matherne). Red swamp crawfish and white river crawfish occur naturally in commercial production ponds, with red swamp crawfish being preferred overwhelmingly by Louisiana consumers. Additionally, ponds with a high percentage of white crawfish appear to have a considerably lower yield potential and thus lower profitability for farmers. We speculate that reproductive patterns, flooding date, water quality and size of juveniles at hatching influence which species dominates. The objective of this project is to evaluate survival and production characteristics of the two species stocked as recently hatched juveniles alone and in combination in (a) September, October and November stocking combinations that attempt to simulate hatching/recruitment patterns observed in ponds, and (b) aerated and un-aerated mesocosms.
Project 4: Computer Modeling of Crawfish Populations. (Support: USDA Special Grant - Aquaculture). A computer model to simulate population dynamics of the red swamp crawfish continues to be developed and allows the user to evaluate the effects of various management strategies on crawfish production and profitability. The model outputs daily and seasonal information on young-of-the-year recruitment, growth, mortality, harvest size, yield and profit based on user inputs that include quantity of brood crawfish stocked, maturity of females, pre‑burrow and burrow mortality, flooding date, forage type and forage planting date, trap density and trapping frequency, and costs associated with user inputs.
Project 5: Update Annotated Crawfish Bibliography (with Sandy Malone, Research Associate). An annotated Louisiana crawfish bibliography that we developed was converted from a Microsoft Access software database to a web-based search and retrieval system and placed on the LSU AgCenter server. It is currently a Beta test site as it is being developed and revised. The database contains ~1,100 citations and 42 subject categories, with over 95% of the articles written by Louisiana personnel (e.g., university researchers, extension personnel, state agency biologists and marketing specialists, etc.). Nearly 725 articles are annotated, and another 350 entries from Crawfish Tales, Louisiana Crawfish Farmers’ Association Newsletters, master theses and Ph.D. dissertations are placed on the Web site but not annotated.
Dr. Terrence Tiersch, Professor
Project 1: Artificial Spawning of Channel Catfish (Hall and Tiersch). We continued our studies of early out-of-season spawning of channel catfish. We used heated water to induce spawning in small ponds (0.12 acres) 2 months prior to the natural spawning season of channel catfish. We evaluated the use of group spawning of females without pairing with males (the standard technique). This work demonstrates the feasibility of using warm-water ponds for early-season spawning of channel catfish. Other studies involved improvement of procedures for collection and storage of gametes. This work is supported by funding from the Louisiana Catfish Promotion and Research Board, USDA and the Southern Regional Aquaculture Center.
Project 2: Cryopreservation of Catfish Sperm (Campbell and Tiersch). We developed or improved cryopreservation methods for the sperm of channel catfish, Ictalurus punctatus. We showed that commercial methods used to cryopreserve sperm of dairy bulls can be successfully applied to this species. In addition, we continued to evaluate production of hybrid catfish by use of cryopreserved sperm from blue catfish, Ictalurus furcatus. This work is supported by funding from the Louisiana Catfish Promotion and Research Board and the Southern Regional Aquaculture Center.
Project 3: Commercialization of Cryopreservation for Aquatic Species (Campbell, Dong and Tiersch). We developed or improved cryopreservation methods for the sperm of fishes such as the channel catfish, Ictalurus punctatus, fishes of the genus Xiphophorus, which are a valuable biomedical research model, and oyster species of the genus Crassostrea, including tetraploid males. We showed that methods used to cryopreserve sperm of dairy bulls can be successfully applied to aquatic species. This work includes development and standardization of product quality assays, biosecurity procedures and efforts to establish markets and pricing. This work is supported by funding from the Louisiana Catfish Promotion and Research Board, USDA-SBIR, Louisiana Sea Grant, Southern Regional Aquaculture Center and the National Institutes of Health.
Project 4: Intracytoplasmic sperm injection (Poleo, Godke and Tiersch). We developed methods for intracytoplasmic sperm injection (ICSI) in eggs of zebrafish, Danio rerio, and Nile tilapia, Oreocromis niloticus. The ICSI technique involves the use of a microscope and micromanipulators to directly inject sperm into eggs. The technique is used for research in livestock and has been adopted for use in human clinics that address male infertility problems. This is the first report of successful ICSI in fishes. This work is supported by funding from the USDA and Louisiana Sea Grant.
Dr. C. Greg Lutz, Professor
Project 1: Conducting cooperative research with a commercial tilapia in the state, focusing on genetic improvement through refinement and commercialization of alternate methods of all-male fry production, including gynogenesis and androgenesis. Bioeconomic characterization of system configurations and production stocks.
Project 2: Evaluation of Freshwater Drum as a Polyculture Species for Louisiana Catfish Producers. This study, proposed by the Louisiana Department of Wildlife and Fisheries and funded by the Louisiana Catfish Promotion and Research Board, addresses a number of issues associated with freshwater drum. In cooperation with Conrad Kleinholz at Langston State University in Oklahoma.
Project 3: Evaluation of cold and salinity tolerances and their interactions in four commercially available tilapia varieties.
Project 4: Selection responses for cold and salinity tolerances in commercially available tilapia varieties and their hybrids.
Project 5: Bioeconomic Modeling on Impacts of Improved System Configurations and Production Stocks in Recirculating Tilapia Production. This work is ongoing. Funding has been provided from sources such as Sea Grant development funds, USDA special grants and a grant from the Louisiana Catfish Promotion and Research Board.
Dr. Steven G. Hall, Adjunct Assistant Professor
Project 1: Design, Development and Testing of a Geothermal Temperature Control System for Aquaculture Broodstock Ponds. An automated control system for use of geothermal water to control temperature for broodstock management in outdoor ponds utilized Campbell Scientific CR23X controllers to operate 600 in-lb torque motors and 15 A relays using 120VAC power to open and close automated 4” PVC ball valves for maintenance of channel catfish Ictalurus punctatus in ponds. Ongoing work focuses on analyzing degree-day concepts with respect to catfish and sunfish spawning (support: La. Catfish Promotion and Research Board).
Project 2: Autonomous Boat Development: A continuing popular project has been design, development and ongoing testing of autonomous boats or “scarecrowbots," solar-powered (15-75W, 12 V panels), battery-operated (rechargeable Pb-acid or NiCd) boats driven by independent dual paddlewheels and controlled by microcontrollers (including Parallax BS-2, BS-2E; Lego MotorMind; and portable computer control), and actuated by flexible shore feelers, and/or by Near Infrared (NIR) or motion-sensing devices to drive predatory birds from aquaculture ponds in an environmentally friendly and non-fatal way. Water cannons and other devices have been used to assist in this process. Initial tests indicate some success, and further development, particularly commercial-scale applications, is ongoing. Use of these boats for additional applications such as water quality monitoring and management is being investigated. A patent is pending on this device (support: La. Catfish Promotion and Research Board).
Project 3: Heat Balance and Applications in Heating of Aquacultural Ponds and Pools. Heating of ponds has been done successfully at LSU but at significant energy expense. Due to the availability of geothermal water, this expense was justified and effective at producing early-season catfish and at maintaining tropical species in limited cases. However, if these technologies are to be effectively adopted, more-effective methods must be found to heat and maintain the heat in ponds. This study has involved a variety of instrumentation mounted in heated and unheated catfish ponds to capture temperature profiles from soil, water and air in mixed and unmixed conditions and to develop a complete heat balance for such ponds. This information can then be used to provide possible solutions to heating applications. Specifically, understanding and knowledge of heat transfer rates, dominant heat transfer mechanisms (e.g. radiation, convection, evaporation) at different times and under different conditions can help in future design of appropriate heating and heat maintenance devices.
Project 4: Optimization of Oyster Shucking with a Heat-cool Methodology. Exploration of improved oyster shucking using heat and cold, as well as instrumentation to measure and refine this process has been supported by Louisiana Sea Grant. Dr. John Supan and Jordan Bradford (Bradford Seafood) have been collaborators, and Daniel Martin produced a PhD dissertation and several publications on this technology.
Project 5: Process Control Engineering to Improve Oyster Cell Culture Research. An automated conditioning system for oysters has been constructed with support from SeaGrant. This system uses a computer-controlled series of temperature probes to measure and control water temperature in 18 250-l tanks. Work is ongoing and focuses on oyster cell biology. An additional system with 36 tanks of 10 liters each is nearing completion and will be used to study a variety of species, including finfish and nitrogen-converting bacteria.
Project 6: Engineering of Artificial Reefs for Oyster Culture and Coastal Restoration. Artificial structures made of PVC, French tubes, rebar and controlled density concrete have been tested in a wavetank at LSU with support from the JB Johnston Science Foundation. Some structures have been tested in coastal waters to assess growth and wave attenuation as means to produce oysters and reduce or reverse coastal erosion.
Dr. W. Ray McClain, Adjunct Professor
Project 1: Evaluation of Selected Aspects of Crawfish Reproduction with Implications for Affecting Production (with Dr. Robert Romaire; support: USDA – Special Grant). Crawfish production is highly variable from year to year and among geographical locations. The most likely contributor to production variability relates to crawfish reproduction. Unlike most other forms of aquaculture, crawfish production does not rely on controlled reproduction and stocking of known numbers of young; rather, it depends solely on natural reproduction from indigenous and/or supplemented broodstock. This project involves monitoring of temperature and free water inside natural burrows over different seasons and use of artificial burrows to ascertain broodstock survival and fecundity associated with various factors such as time at stocking, previous habitat and physiological condition of broodstock prior to burrow occupation. Determinations will also be made as to whether survival and reproduction within the burrow differ for crawfish that voluntary burrow as compared with those that are forced to burrow due to pond dewatering.
Project 2: Investigation of Possible Linkages between Rainfall Patterns and Crawfish Production in South Louisiana (with Dr. Robert Romaire; support: Louisiana Crawfish Promotion and Research Board Grant). Crawfish production variability is most certainly affected by weather patterns. Annual yields may be highly correlated to rainfall patterns, particularly during critical periods, such as late summer/fall when crawfish are reproducing and emerging from burrows. Therefore, this study undertakes to examine, in detail, rainfall patterns (amounts and frequency) from multiple official weather stations in the state over the last 20 years and to compare (via statistical correlations) rainfall patterns and published annual crawfish yields statewide, and by parish, to determine the extent to which historical correlations exist. Comparisons will be made with regard to rainfall patterns seasonally, monthly, bi-monthly, quarterly and for other specified periods.
Project 3: Comparisons of Crawfish Forage Ratoon Crop Characteristics Among Selected Rice Cultivars Under Extended Flooded Conditions. Domestic rice cultivars are developed primarily for their grain yielding and milling characteristics, yet the majority of the crawfish acreage in Louisiana revolves around a ratoon forage crop from these domestic varieties. Forage production and persistence traits vary among the various varieties used for rice-crawfish rotational production systems; therefore, this study is investigating the differences among the ratoon crops of the most commonly used rice varieties under the extended flooded conditions of a crawfish pond.
Dr. John Supan, Adjunct Associate Research Professor
Project 1: Operation and Management of Grand Isle Oyster Hatchery: (Support: Sea Grant and other sources). Annual operation of oyster hatchery for supporting collaborative oyster research and education by faculty and students from LSU and other in-state and out-of-state institutions, as well as industry outreach and larval supply.
Project 2: Grand Isle Aquaculture Park: Initial site and culture technology evaluations for off-bottom culture of specialized oyster strains resulting from various oyster research in a permitted area of Caminada Bay.
Project 3. Coordination of the Gulf Oyster Industry Program (support: Sea Grant). Coordination of industry and scientific review panels for administering oyster research proposal submissions focused on annual Gulf oyster industry needs assessments
Project 4: Evaluation of Triploid Oyster Culture and Outreach to Oyster Industry (support: Sea Grant). Improved methods to chemically induce triploidy in oysters and continued evaluation of triploid oysters for industrial utilization as a new “summer crop”.
Project 5: Development of Tetraploid Oyster Broodstock (support: Sea Grant). Developing new oyster broodstock line for improving hatchery production of triploid oysters
Project 6: Evaluation of Perkinsus marinus of. Louisiana Public Oyster Grounds and Development of Dermo Industry Advisory. (support: La. Oyster Task Force funded). Annual evaluation of Dermo. levels in seed and market-size oysters from ten sites within public oyster grounds of Louisiana. Includes annual industry advisory in the task force’s newsletter.