Performing Department
(N/A)
Non Technical Summary
The traditional fish farming industry in the U.S. is currently faced with rising costs, labor shortages, competition from lower cost imports, increasing environmental regulation, and decreasing water supplies. Sales of the domestic channel catfish industry alone fell from $423 million in 2011 to $301 million in 2014. Catfish acreage in Arkansas which totaled 30400 acres in 2007 (NASS 2008), was reduced to 8200 water acres in 2013, down 1500 acres (15%) from 2013. Currently, catfish production in Arkansas is estimated to be less than 5000 water acres. As profit margins are shrinking in the catfish industry, many Arkansas fish farmers are searching for alternative species with greater profit potential. Largemouth bass (LMB) is one such H.V.S. It is estimated that there are around 2000 acres currently in production of LMB food fish in Arkansas and no more than 3000 acres in production throughout the United States. The majority of market size LMB produced in Arkansas are sold live to ethnic markets in Chicago, New York and Canada. Although it is estimated that LMB production costs can range from $4 to $5 per pound, farm gate prices exceed $5.00 per pound and the demand has exceeded the supply for several years. LMB production in open ponds is restricted by significant obstacles related to their behavior and biology. LMB fingerlings must be crowded and trained to accept formulated feed at a young age. Many fish farmers do not have the facilities or expertise to house and maintain these fish during the feed training process and prefer to purchase 6 inch advanced feed trained fingerlings. However, production of advanced fingerlings is variable and costs often exceed $1.00 per fish. This variable production and major cost risk arises from the low survival following the introduction of 2 inch feed trained LMB fingerlings into open ponds. It is not uncommon for 40 to 50% of the stocked fingerlings to lose the learned pellet feeding behavior shortly after being transferred from crowded feed training tanks to open ponds resulting in large losses due to cannibalization and starvation. Ponds are typically stocked in early June and summer temperatures prevent the frequent seining and grading of the fingerlings to prevent cannibalism. Our experience at J.M. Malone and Son, Inc. has shown LMB fingerlings at this stage are also very susceptible to bacterial infections which have proven difficult to treat in open ponds. As a result, survival of 2 inch feed trained bass fingerlings to 6 inch advanced fingerlings averages 25-40 %. We have also observed that advanced LMB fingerlings are very susceptible to predation by herons and cormorants. Sub adult LMB require high protein feeds, well oxygenated water, will not tolerate poor water quality or low oxygen events and are highly susceptible to blue green algae toxins. Feed intake is greatly reduced in the warm summer months when nocturnal oxygen concentrations approach 40% saturation and afternoon pH exceeds 8.5. Feed conversion ratios are often greater than 4 or 5 and yields in ponds rarely exceed 2000 lbs/acre and are often as low as 1000 lbs/acre. Many of the obstacles limiting LMB production in open ponds can be overcome when the fish are confined to an intensive tank or raceway. However, most fish production in Arkansas and the southeastern U.S. occurs in traditional open ponds. The Partitioned Aquaculture System (P.A.S.) developed by Clemson University, is an example of intensive confinement using a pond-based system. Although several variations of the P.A.S., such as the split pond production system and the in-pond raceway system, have been adopted by the catfish industry, these systems have not been widely accepted due to the high cost of construction and the low prices being paid for catfish (approximately $1/lb). There are nearly 2000 acres of P.A.S. variations devoted to catfish production in Mississippi, Alabama and Arkansas accounting for less than 2% of the total acres of catfish production nationwide. Most of those acres are split pond systems. H.V.S. such as LMB have the potential to generate high gross revenues commensurate with the higher construction costs of such systems. However, LMB require considerably higher protein diets and better water quality than channel catfish for optimal growth. Therefore, any in-pond confinement based production system used to produce H.V.S. such as LMB requires significant modification to 1) improve solids removal from the fish confinement zone, 2) process increased nitrogen inputs resulting from the feeding of higher protein feeds, 3) monitor and control oxygen and pH, and 4) manage feed input to eliminate waste. The costs associated with such modifications need to be justified. The ability to rapidly concentrate, collect and process solid wastes from intensively managed pond based production systems such as the P.A.S. has the potential to vastly expand the production of H.V.S. such as LMB, hybrid striped bass, bluegill sunfish and black crappie from domestic fish farms which are currently producing channel catfish and receiving small economic returns for their product. Such technology is important for U.S. fish farmers to remain competitive with fish imports. The development of an in-pond confinement based production system for H.V.S. would allow fish farmers to continue using their land for the production of food fish while 1) minimizing costs and maximizing returns through greater control of the production process, 2) operating with zero discharge avoiding effluent regulation and limiting water use and, 3) competing more effectively with imported fish by producing more fish per acre than traditional pond culture with less labor and energy.
Animal Health Component
(N/A)
Research Effort Categories
Basic
(N/A)
Applied
(N/A)
Developmental
100%
Goals / Objectives
The primary goal of this project is to finalize the design of all components of a commercial scale modified P.A.S. by installing and operating a second generation prototype in-pond tank. The objectives of this proposal are to: 1) Field test the second generation commercial scale in-pond tank prototype to: a) verify solid waste removal ability, b) test efficiency of three circulator designs, c) develop harvest technologies, d) compare production, fish management and oxygen dynamics of in-pond tank design to traditional round tank and, e) evaluate the cost efficiency and investment feasibility of in-pond tank prototype in comparison to traditional round tank production system, 2) Evaluate an experimental dual basin algal reactor for improved oxygen dynamics and, 3) Evaluate nutrient management and algal concentration reduction methods.
Project Methods
Objective 1) The second generation commercial scale in-pond tank prototype designed and built in phase I will be installed in a modified one acre P.A.S. with an experimental dual basin algal reactor. A traditional round tank of the same dimensions with dual drains will be installed on the levee of the same experimental algal reactor. Installation will begin September 1, 2018.One hundred thousand 60 day old, 2 inch feed trained LMB fingerlings produced on our facility will be stocked into each tank in May 2020 and reared for a minimum of 120 days. They will be fed a 48% protein ration multiple times per day via automated feeders according to a proprietary feeding program. Supplemental oxygen supplied via pump and saturator cones will be used to maintain oxygen saturation in each tank above 80%. Both tanks (and both reactors) will be fitted with optical dissolved oxygen probes linked to a single oxygen monitor. Complete fish harvest of both tanks is planned for September 2020.Objective 1a) Throughout the 2020 production period water samples will be collected weekly at a standardized time from the a) tank influent, b) sidewall tank effluent and, c) center drain tank effluent.T.S.S. levels will be quantified and characterized.A 10 gallon water sample will be serially filtered through the sieves with mesh sizes of 400, 200, and 100 µm. The collected solids on each sieve mesh will be rinsed off with distilled water, which will be filtered using glass fiber filters. Each glass filter will be oven dried (103-105°C), and TSS will be calculated from the difference in dry weight of each glass fiber filter before and after filtering the sample. Using the TSS fraction data, changes in TSS concentrations through the system will be characterized.Objective 1b)Circulators will be built in our shop during December 2018 and January 2019. Between the months of June 2019 and August 2019 the three styles of circulators will be installed within the second generation in-pond tank prototype and tested. The motor will be powered by a variable frequency drive whereby speed of the circulator (rpm) can be controlled and true power (kW) can be measured. Detailed measurements of water flow rates (gpm), water velocity (ft/sec), and energy use (kW-h) will be made. This data will be used for determination of advantages and disadvantages of each design. Flow rate (gpm) will be measured at the tank inflow, sidewall outflow and center drain outflow over a variety of speeds while maintaining approximately six inches of head in the second generation in-pond tank prototype. Energy consumption and flow rates will be characterized after initial performance testing. Water velocities within the second generation commercial scale in-pond tank prototype will be measured. The relationship between circulator style, speed (rpm) and water velocity (ft/sec) in the tank will be characterized after performance testing.Objective 1c) Between the months of February and May 2019 a modified clam shell crowder/grader will be designed and constructed for use during harvest in the fall of 2020. Cost of labor and equipment required for harvest will be compiled.Objective 1d)Specific data collected during the 2020 production season will include: 1) observations related to fish management, 2) pounds of fish produced, 3) survival, 4) feed conversion and, 5) oxygen readings.Objective 1e) Specific data collected during the 2020 production season will include: (1) initial investment capital required for construction of in-pond tank prototype (including the costs of structures required, earth moving costs, costs of labor required for installation, and cost of electrical wiring) and (2) variable cost that include inputs such as fish fingerlings, feed, labor costs, electricity usage, repair and maintenance, and interest on operating capital required to operate in-pond tank prototype. This will be compared to fixed and variable costs associated with traditional round tank production. Breakeven prices (BEP's) and breakeven yields (BEY's) to cover total variable costs (VC) total costs (TC's) will be calculated as described in Engle (2010). Sensitivity analyses will be developed to assess the effects of varying levels of yields, feed prices, and fish prices on BEP's. An analysis of the long-term profitability of investing in in-pond tank prototype and traditional round tank systems will be developed by calculating the (1) payback period (PBP), (2) net present value (NPV), and (3) modified internal rate of return (MIRR) using standard capital budgeting techniques. A discount rate of 10% will used for NPV calculations. The sensitivity of MIRR to varying levels of initial capital investment, fish price and other variables that tend to influence feasibility will be developed to assess the effect of these variables effect on investment feasibility.Objective 2) Water samples will be collected weekly from the one acre experimental dual basin reactor during the 120 day production period in 2020 (objective 1) at a regular time from both basins. Samples will be analyzed for chemical oxygen demand (COD), ammonia-N, nitrite, nitrate and phosphorous using a V-2000 Photometer. Dissolved oxygen will be measured hourly in both reactors with the YSI 5500D. Secchi disk measurements will be taken daily at 12 pm in both reactors. An analysis of covariance (ANCOVA) test will be performed to identify differences in water quality between the basins using SPSS 12 for windows (SPSS Inc., Chicago, IL). Sampling days will be considered as covariance, and the main effect comparison will be conducted using Bonferroni's method.Objective 3) Tank trials will be conducted to evaluate the effect of various nutrient and phytoplankton reduction regimes. Three different system configurations will be operated in triplicate. Each system will consist of a LMB tank (100 gallon) and 2500 gallon algal reactor tanks. The LMB tanks will be plumbed with dual drains whereby effluent containing concentrated solid waste will be drained through a center bottom drain can be directed separately from the sidewall drain which will contain very little solid waste. A continuous flow of water will be pumped to the LMB tank from the algal reactor. The algal reactors will be circulated continuously. One thousand 60 day old, 2 inch feed trained LMB fingerlings produced on our facility will be stocked into each tank in June 2019 and reared for 120 days. They will be fed a 48% protein ration by automatic feeders according to a proprietary feeding program. Supplemental oxygen supplied via air stones from a liquid oxygen tank will be used to maintain oxygen concentrations in each tank above 80% saturation. We anticipate harvesting 800 6 inch LMB from each tank at the conclusion of the trial. Our existing pool trial system will be modified in April and May 2019. Ammonia-N, nitrite-N, nitrate-N, phosphorus and COD in the algal reactors will be measured weekly at a scheduled time using a V-2000 Photometer. Dissolved oxygen will be measured daily at 7 am. Secchi disk depth will be measured daily at 12 pm. An analysis of covariance (ANCOVA) test will be performed to identify differences in water quality between the different systems using SPSS 12 for windows (SPSS Inc., Chicago, IL). Sampling days will be considered as covariance, and the main effect comparison will be conducted using Bonferroni's method.