Evaluation of a Confinement System for the Production of Channel Catfish
Neil Pugliese, David Heikes and Carole Engle

A confinement system for the production of channel catfish Ictalurus punctatus was evaluated at the University of Arkansas at Pine Bluff Aquaculture Research Station.  This research was carried out for two separate growing seasons each with its own unique experiment.  Each study consisted of ten 0.1-ha ponds. A barrier was constructed in five of these ponds to partition the pond into 1/3 and 2/3 sections. The other five ponds were left as traditional open ponds and used as controls.  When fingerlings were physically separated from larger carryover fish, significantly greater yields of fingerling (stocker) fish were achieved.  There were no significant differences in survival, feed conversion ratio, or growth.   The partial budget analysis revealed a positive net change of $367/ha or $38,125 for a 104 ha catfish farm at a market price of $1.54/kg of additional stockers produced. Yields, feed conversion ratios, and daily growth of food fish were significantly lower in the confinement system in the Year 2 single-batch study.  Seining efficiency was significantly greater for the confinement system.  The partial budget analysis showed a change in revenue of -$2,186.00/ha or -$227,334.00 across a 104-ha farm at a foodfish market price of $1.54/kg.  The confinement system improved profits over the traditional multiple-batch system by taking advantage of maintaining different sizes of fish separately.  However, yields were not as high as in the open-pond stocker single-batch system.  Further research is needed to identify the best way to utilize the confinement system in a commercial setting. 

Catfish Feeding Frequency Study, Understocking with Large Stockers
Carole Engle and Adam Nanninga

Twelve 0.10-ac ponds were each stocked with 2,000 lb/ac carryover fish (average weight of 0.88 lb) and 4,500 fingerlings (150 lb/1,000).  Treatments were feeding either every day, every other day, or every third day, and fish were fed to apparent satiation on the days fed with a 32% protein floating catfish feed.  Both stockers and carryover fish grew significantly better when fed every day.  Yields of market-sized fish were 860 lb/ac greater when fed every day and 1,000 lb/ac more when fed every other day as compared to feeding every third day.  Fillet dressout yields were significantly greater for fish fed every day.  The feed conversion ratio was greater with every day feeding, but the additional revenue from the higher yields more than compensates for the improved feed conversion ratio of feeding less than every day.

Winter Feeding of Channel Catfish
Carole Engle and Adam Nanninga

Ten 0.25-acre ponds were stocked with 880 lb/ac market-sized fish (>1.25 lb) and 2,640 lb/ac of stocker-sized fish (250-500 g).  Treatments were either fed or unfed over the winter.  The average weight at harvest of market-size fish was similar (931±58 g for fed fish; 958±45 g unfed) (P>0.05).  Sub market-size catfish that were fed over the winter lost less weight on average than those not fed over the winter (P<0.05). Fed fish averaged 260±8 g at harvest while unfed fish averaged 245±139. However, this difference was not great enough to affect the overall net yield of fish harvested.  Net yield at harvest averaged -250±93 kg/ha for fed ponds, and -375±195 kg/ha for unfed ponds.  Survival averaged 95% for both treatments. 

Effect of Density of Understocked Stocker Catfish on Production
Carole Engle, Brent Southworth, and Kraig Ruebusch

A multiple-batch study was conducted using stocker catfish (0.09 kg/fish) and carryover fish (0.39 kg/fish) to look at the effects of different stocker densities on fish production.  Twelve 0.1 ha ponds were stocked with 7,400; 11,120; or 14,825 stockers /ha and equal weights of carryover fish (2,268 kg/ha).  No significant differences were detected for gross, net, and net daily yields, growth (g/d), or survival.  Sub-marketable yield (< 0.57 kg) increased as stocking density increased.  However, marketable yields (> 0.57 kg) were not affected by density.  Carryover fish in high-density ponds had a significantly lower (P < 0.05) mean weight at harvest, but mean stocker weight was not different across densities.  The study indicated the possibility that stockers compete with large carryover fish, particularly at higher densities.

Hybrid-103 Catfish Growout Challenge
Carole Engle and Ganesh Kumar

Channel catfish (NWAC 103) and hybrid catfish (channel-blue) fingerlings (6-8 inches each) were stocked at 6,000/acre, five 0.25-acre ponds of each.  There was no significant difference (P <0.05) due to the type of fish in growth, yield, total feed fed, survival, seinability, average weight at harvest, or dressout yield.  Feed conversion ratio was significantly lower for the hybrids.  A partial budget analysis revealed that benefits from the lower feed costs that result from the lower conversion ratio for the hybrids were less than the additional cost of purchasing the hybrid fingerlings.

2005 -
Focus Group Study to Evaluate Preferences for Added-Value Products Derived from Wild Caught and Farm-raised Fish with Emphasis on Farm-raised Hybrid Striped Bass
Ivano Neira and Carole Engle

Four focus group meetings (white American groups, one African American, and one Hispanic) were conducted in Little Rock to evaluate preferences for added-value products derived from wild caught and farm-raised fish with emphasis on farm-raised hybrid striped bass. Contamination, price, promotion, fish variety, packing showing the product and labeling with recipes, nutritious content, and USDA certification were critical factors mentioned to be able to increase fish consumption. Individual fillets in a resealable bag containing either fresh or frozen were preferred and desired. All the participants have positive perceptions of farm-raised fish but none of them were aware of farm-raised hybrid striped bass.

Efficiency Change and Technological Progress in the U.S. Catfish Processing Sector, 1986-2005
Aloyce R. Kaliba, Carole R. Engle and Larry Dorman

In this paper, we measured productivity growth of the catfish processing sector in the U.S. over a period of 1986 through 2004 to find out how efficiently catfish processed goods are produced. The results indicate that between 1986 and 2005 there was no technical change or adoption of new processing techniques with significant impact. Technical efficiency changes were variable and varied with type of fish size processed. Between 1986 and 1995 the trend on technical efficiency change was negative as the industry struggled to establish the most efficient fish size to process. A positive trend on technical efficiency change is observed between 1995 and 2005. This means that under current processing technology, input resources are continuously allocated optimally. The focus should be on developing and adopting new processing innovations that will increase productive efficiency and long-term competitiveness of the catfish-processing sector.

Potential Economic Impacts of Adding Value to Catfish Processing Wastes
Aloyce R. Kaliba and Carole R. Engle

Processing of channel catfish (Ictalurus punctatus) yields substantial quantities of unutilized processing wastes (up to 47% of the fish weight). A regional economic-multiplier model was developed to assess the economic impacts of processing the wastes into fishmeal and fish oil using a 2002 IMPLAN database. In 2002, the four states delivered 271,734 metric tons to catfish processing plants, generating 354 metric tons of waste per day that can be processed into fishmeal and fish oil by two plants with a processing capacity of 200 metric tons per 24 hours (3 shifts), and employing 20 individuals. A catfish processing plant would add three employees for sorting and then sell the waste to fishmeal and fish oil plants at $0.22/kg to generate about $28 million in annual sales. Catfish farmers will receive about $4 million, based on farm cost shares of about 15%. Results indicated that these activities would generate $79 million in total economic output through direct, indirect, and induced impacts. This economic expansion would create 600 jobs and labor income amounting to $13 million through direct ($4 million), indirect ($7 million), and induced ($2 million) impacts. In addition, about $10 million in federal and state tax would be generated. While the investments created more jobs in the directly affected industries, it created higher paying jobs in industries that are indirectly linked.

Productive Efficiency of Catfish Farms in Chicot County, Arkansas
Aloyce R. Kaliba and Carole R.Engle

Technical, allocative, and cost efficiency measures of a sample of small and medium sized catfish farms in Chicot County, Arkansas were estimated using a weight-restricted data envelopment analysis technique. A measure of cost efficiency is used to determine operator characteristics, farm practices, and institutional support services that are likely to lead to higher levels of efficiency. Experience of the operators and extension contacts were important factors positively influencing farm level efficiency. Extension services in Chicot County generated about $5.2 million in cost savings among catfish farms or about $2,737 per contact. Importantly, higher cost efficiency of catfish farm efficiency in Chicot County, Arkansas, can be achieved by adjusting inputs used in production to optimal levels rather than by adjusting the scale of operation.

An Evaluation of the Potential Market for and Uses of Catfish Processing Waste
Aloyce R. Kaliba and Carole R. Engle

Processing of channel catfish (Ictalurus punctatus) to produce sellable products yields substantial quantities of unutilized processing waste. Depending on the product forms dictated by the marketing strategy of the processor, up to 47% of the fish weight is usually discarded as waste. Utilization of by-products from catfish processing is increasingly becoming important because the quantity of processed fish (a more than 13-fold increase in 24 years) has also increased the quantity of waste to be disposed and there is increased knowledge on the benefits of utilizing these wastes for different uses. In this study, an attempt is made to compile and discuss potential value-added products that can be produced from catfish processing wastes. The focus is on documenting current application and use, identifying available technologies to manufacture the products, and identifying existing and potential markets for these products.

The Effect of Understocking Density of Channel Catfish Stockers in Multiple-Batch Production
Brent Southworth and Carole Engle

A multiple-batch study was conducted using stocker catfish (0.20 lb/fish) and carryover fish (0.86 lb/fish) to look at the effects of different densities of stockers on overall fish production. Twelve 0.25-acre ponds were stocked with 3,000; 4,500; or 6,000 stockers/acre, and 2,000 lb/ac carryover fish. Partial harvest one removed 1,500 lb/ac and partial harvest two removed 1,000 lb/ac. Survival of both size classes of fish was relatively high and not significantly different (P > 0.05) due to stocking density. Survivals were 78-88% for stockers and 92-97% for carryover fish. Although there appeared to be a trend of increasing yield with increasing density, no significant differences were detected for gross, net, and net daily yields. Marketable yields (> 1.25 lb) were not affected by density. However, sub-marketable yield (< 1.25 lb) increased as stocking density increased. The last seven weeks of culture, there was a trend of declining carryover growth at the high stocking densities, however no significant differences were measured (p = 0.08). Carryover fish at low density had a significantly higher (P < 0.05) mean weight at harvest, while there were no significant differences in average stocker weight at any sampling period. This study found that it is possible that stockers have higher survival, reach market size faster, and may compete with carryover fish better than smaller fingerlings when stocked in multiple-batch.

2004 -
Economic Impact of the Catfish Yield Verification Trials
Aloyce R. Kaliba and Carole R. Engle

Yield verification programs are public demonstrations of the implementation of research-based Extension recommendations on a commercial-scale. Participating farmers agree to manage a section of their farm according to extension recommendations. Cooperating farmers keep records on production inputs and outputs. Extension personnel monitor various production parameters and make management recommendations to the producer on a regular basis. The data are analyzed to determine the economic gains associated with adopting the extension recommendations. The objective of this study was to estimate economic returns from the pilot CYVT trial. Economic benefits of the trial were estimated as economic surplus accrued to consumers and producers, generated after adopting the new management recommendations arising from the trial. A variable factor proportions and a four-commodity model was used to estimate changes in producers' and consumers' surplus due to increased quantities of catfish retail products (i.e., whole catfish fish, catfish fillet, steak, and nuggets). Increased quantities of catfish retail products are due to a research-induced shift in supply of live catfish. The sum of accrued net economic surplus by Arkansas catfish farmers and U.S. consumers minus the CYVT investment cost was used to generate 11-year (1993-2002) flows of net economic benefits, and to estimate three economic profitability measures (i.e., Internal Rate of Return (IRR); Modified Internal Rate of Returns (MIRR); and Net Present Value (NPV). On average, the change in economic surplus for catfish producers in Arkansas was $61 million for the entire 11-year period. The average gain per year was $11 million. Total consumer's economic surplus and total net returns were $6 and $67 million, respectively. On average, catfish consumers gained about $1 million every year, for 1993/02. These results represent a distribution of benefits between producers and consumers of 92% and 8% respectively. All three economic profitability measures (IRR, MIRR, and NPV) were positive, indicating that the CYVT was economically profitable. Sensitivity analyses were conducted to analyze the effect of varying the elasticity of substitution and supply elasticity of live catfish. The results indicate that adoption of extension recommendations should reduce the cost of producing catfish by more than 5% for the trials to be economically profitable.

Risk Analysis of Trout Aquaculture in Transylvania County, North Carolina
Aloyce R. Kaliba and Carole R. Engle

Commercial trout farming started in NC more than 45 years ago. North Carolina ranks second behind Idaho in trout production. In 2002, 21 of the 57 firms in North Carolina were located in Transylvania County. Data on resource inputs and production levels collected from 13 of the 21 trout farms in Transylvania County were used to develop enterprise budget for a medium-sized farm producing 68,182 kg/year (150,000 lb/yr). The estimated net return was $8,644. Simulation was conducted to assess the impact of price and production variability on net returns. The results show that when price and production variability are considered, about 36% of the farms were not likely to breakeven and 18% of the farm were likely to get less than $8,644 in net returns. Only 45% of the farms were likely to get above $8,644 in net returns.

The Economics of Stocking Size of Fingerling and Stocker Catfish in Foodfish Production Ponds
Steeve Pomerleau and Carole Engle

A two-year catfish farm model was developed using mathematical programming techniques. The LP model focused strictly on the modular catfish production system. The objective function was to maximize expected net returns over a two-year period by selecting the optimal stocker production strategy subject to pond balance, fish balance, and other production constraints. The model allocated approximately 30% of the farm water-area to stocker production and the remaining 70% to growout. The model selected stocker production from 10-cm fingerlings stocked at 100,000/ha because this strategy resulted in the lowest cost/kg of stocker produced because it generated the highest yields (kg/ha). In the model, fingerlings were grown for a year and the resulting stockers were transferred to growout ponds at a size of 255 g. Sensitivity analysis indicated that the model was robust to large variations in financial variables. The profit maximizing strategy selected by the model did not significantly change with variations in harvest costs from 0-200% of baseline, foodfish prices from $1.10 to $1.76/kg, fingerling prices from 50 to 150% of baseline, feed price from $225 to $300/metric ton, feed conversion ratios from 1.5 to 3.0, or mortality rates from 0 to 0.33%/day.

The Effect of Multiple-batch Channel Catfish Ictalurus punctatus Stocking Density and Feeding Rate on Water Quality, Production Characteristics and Costs
Brent E. Southworth*, Carole R. Engle, Nathan Stone and Andrew A. Goodwin

With increases in production intensity, farmers must seriously evaluate the effects of interactions among stocking density, feeding rate and water quality on production. Fingerlings 4-6 inches were understocked at four densities ranging from 3,500-14,000 fish/acre with 2,000 lb/ac of 0.81-0.99 lb fish into 12 0.25-acre ponds. Fish were fed daily to apparent satiation with (32% floating feed). Water quality measurements included nitrite, nitrate, total ammonia-nitrogen, Secchi disk, chlorophyll a, total nitrogen, total phosphorus, chemical oxygen demand, total alkalinity, total hardness, chlorides, pH, temperature and dissolved oxygen. Costs of producing channel catfish at different stocking densities were estimated. Feed conversion ratios ranged from 2.33 to 1.61. Maximum daily feeding rates were 128, 108, 164 and 160 lb/ac/d in the 3,500; 7,000; 10,500 and 14,000 fish/acre densities respectively. Gross yields were 6,763; 5,263; 7,363 and 7,183 lb/ac in the 3,500; 7,000; 10,500 and 14,000 fish/acre densities respectively. Water quality did not deteriorate with increases in stocking density and showed few significant differences at sampling periods and no differences when averaged across the production season (P < 0.05). Total ammonia-nitrogen levels reached a maximum of 5.1 ppm in the 10,500 fish/ac stocking density. However, un-ionized ammonia did not reach toxic levels in any treatment.

Reducing Catfish Farm Losses Due to Dockages Assessed by Processing Plants
Nathaniel Wiese, Carole Engle, and Jeremy Trimpey

Dockages can have a significant effect on catfish farm revenues. This study was conducted to quantify common dockages, examine seasonal and yearly variations in dockages assessed, and determine optimal production practices given various dockage scenarios. A convenience survey of invoice records from 30 commercial catfish farms and 10 processing plants provided 3,686 daily catfish load records that were used to quantify dockages. A linear programming model was developed to examine optimal production practices given 11 alternative production scenarios with five size grading technologies subject to 24 types and levels of dockages. The survey revealed that 95% of catfish loads delivered to processing plants between 1997-2002 were assessed dockages that resulted in an average farm revenue loss of 2.45% over the study period. The most profitable production practice, with respect to plant discount policies is to grow catfish in a single-batch system for the entire growing season. Net grading was used if the value of small fish returning to the pond was not accounted for. However, off-flavor, cash flow constraints, disease, marketing, and other factors force farmers to use multiple batch systems. The UAPB grader was selected primarily when the value of fish returned to the pond was accounted for. This study suggested that there are combinations of management strategies and grading technologies that can be used to minimize losses due to dockage. Larger farm sizes and increasing minimum market sizes of fish are conditions under which a move to either single-batch production or intensive grading would result in higher farm revenues. Smaller farms, with multiple-batch production systems would have higher farm revenues with net grading at 5-10% tolerances, but with the UAPB grader at 0% tolerances.

Effect of Increasing Stocking Rates of Channel Catfish on Phytoplankton Composition
Peter Perschbacher, Brent Southworth and Carole Engle

Phytoplankton samples taken at two-week intervals during a production experiment with varying stocking rates of channel catfish did not reveal differences in percentage composition or frequency of off-flavor species among treatments. Adequate nutrients for the typical bluegreen blooms that dominate, including off-flavor species, were judged present at all levels.

2003 -
Impact of the Catfish Industry on Chicot County, Arkansas
Aloyce Kaliba and Carole Engle

An input/output model was used with catfish production survey data to quantify the economic contribution of the catfish industry in terms of creating new dollars, jobs, and income to the local economy. Total employment created in Chicot County by businesses directly or indirectly involved with the catfish industry was 2,665 jobs, representing 48% of all employment in Chicot County. Total tax revenue generated was $22 million.

In-pond Floating Grader Trials and Economics
Jeremy Trimpey and Carole Engle

Replicated trials were conducted in experimental and commercial ponds to evaluate the in-pond floating grader. The UAPB grader returned more than 2-4 times more sub-harvestable fish to the pond for additional growth than the traditional live car.

Partial budget results indicated positive net benefits for all farm sizes (160 acres, 320 acres, 640 acres and 1,200 acres). Net benefits increased with farm size, market price, and increased dockage penalties.

Economic Impact of the Trout Industry on Transylvania County, North Carolina
Aloyce Kaliba, Carole Engle, Steeve Pomerleau, Jeffrey Hinshaw and Debra Sloan

A survey of trout farmers in Transylvania County, North Carolina was used to estimate the impact of the trout industry on the county?s economy. The study showed that, in 2002, the trout industry generated about $9 million in economic output, created 201 jobs and generated $3 and $0.9 million, respectively, as labor income and tax revenue. These impacts are particularly important in a county where economic prosperity depends on locally available jobs and diversification of economic activities.

Effect of Proposed Effluent Treatment Options for Hybrid Striped Bass
Yong-Suhk Wui and Carole Engle

A mixed integer programming analysis of effluent treatment options was used to evaluate the farm-level impacts of proposed effluent treatment options for hybrid striped bass farms. Settling basins and constructed wetlands entailed high costs. No annual draining and not flushing the pond water were the best treatments. However, additional work is needed on the long-term risks of not flushing and not draining hybrid striped bass ponds.

Effect of Stocking Density on Catfish Production Characteristics
Brent Southworth and Carole Engle

Channel catfish were stocked at 3,500, 7,000, 10,500, and 14,000/acre in single-batch production. Mean weight at harvest and growth of catfish decreased significantly as stocking density increased. Net yield and net daily yield increased significantly as stocking density increased, but marketable yield was highest at 7,000/acre.

Growth of Stocker Channel Catfish at Three Stocking Rates
Bart Green and Carole Engle

Stocker channel catfish (0.53 lb) were stocked at 3,500, 4,500, or 5,500/acre in single-batch culture for a 163-d production cycle. Net yield of catfish increased linearly with increased stocking rate, while mean size at harvest decreased linearly with stocking rate. Fish average weight ranged from 1.6-2.2 lb at harvest. At harvest, 8% of the population was less than 1.5 lb/fish for the low stocking rate, and 21% of fish weighed less than 1.5 lb/fish for the high stocking rate.

Water Quality in Channel Catfish Ponds Receiving Varying Protein Levels and Alternate Day Feeding Patterns
Peter Perschbacher, Carole Engle and Carlos Leyva

On several sample dates, every day feeding of 32% protein feed compared to every other day feeding at 28, 32 and 36% protein feeds resulted in statistically lower water quality in the water quality parameters TAN, dissolved oxygen, and nitrite-nitrogen levels. However, chlorophyll a levels did not significant differ.

2002 - 
Economic Effect of Stocker Catfish (Ictalurus punctatus) Production on Farm Profitability.
Steeve Pomerleau and Carole Engle
 
Traditionally, farmers understock 9-27 g fingerlings directly into growout ponds in multiple-batch production. However, some use a three-phase strategy, where fingerlings are raised to stocker-size (27-340 g) in single-batch for one growing season, before transfer to growout ponds. Does the use of stockers improve farm productivity and profitability? A series of pond studies were conducted at the University of Arkansas at Pine Bluff on fingerling and stocker production and performance in growout ponds. Enterprise budgets were developed based on three sizes of farm (65, 130, and 260-ha) and eight production strategies. Five strategies involved the production of stockers (114, 135, 176, 255, and 361-g) thereafter stocked in growout ponds at 11,250/ha, in single-batch production. The three other strategies involved understocking fingerlings (6, 12, and 37-g) directly into growout ponds at 15,000/ha with 1,369 kg/ha of large 580-g catfish to simulate multiple-batch production.

Results indicated two principal profit-maximizing strategies (Table 1). One strategy was to understock 37-g fingerlings in multiple-batch growout ponds. The other was to produce 255-g stockers before transfer to growout ponds. Three main factors affected the relative profitability of the 255-g stocker versus the 37-g fingerling strategy. As farm size increased (Table 1) or pond size decreased, the stocker strategy became more profitable than the fingerling strategy because it used resources more efficiently. The stocker strategy was not as profitable for small farms or for larger ponds because it was more difficult to balance the number of stockers produced with the number stocked in growout ponds, resulting in wasted resources. The third factor was the growth rate of the stockers in growout ponds. As the growth rate of the stockers increased, the relative profitability of the stocker strategy increased.

This static analysis indicated the profit-maximizing strategy for a single year. However, the analysis did not consider the effect of each strategy on farm profitability over multiple years, the increased risk of mortalities and off-flavor, nor the logistics of producing and stocking successive batches of stockers throughout the season across the whole farm. Additional research is needed in a dynamic framework to evaluate the effects of these additional factors.

Implications of Import and Price Setting Policies for the Catfish Industry
Kwamena K. Quagrainie and Carole R. Engle

Total imported fish fillets from Vietnam has increased by about 7000% since 1995 causing themarket share of U.S. catfish fillets to decline from about 99% in 1995 to about 85% by December of 2001. Consequently, the price of catfish that processors pay to farmers has declined to a ten-year low, threatening the sustainability of the industry. Price setting is a policy being considered by major producer groups such as the Mississippi Catfish Producers Marketing Association (MCPMA) and the Catfish Bargaining Association (CBA) to help enhance revenue and sustain the industry. Fixity of assets in the catfish industry suggest a relatively inelastic supply response from farmers therefore, revenue enhancement can be better achieved through price increases than quantity increases.
This study investigates Vietnamese export of fish fillets to the United States and its impact on domestic catfish prices as well as the welfare implications for opting price-setting policies by producer groups. Structural equations and simulation models are used to accomplish these objectives.

The results indicate that the desired price by both processors and farmers and the actual transacted price matched fairly closely until the last quarter of 2001. The desired price is what the price should have been given market conditions. This equilibrium desired price is found to have been affected negatively by excess supply, including the quantity of catfish processed, the quantity of catfish fillets sold, and the quantity of fish fillets imported from Vietnam. Estimates of lost farm revenue due to the non-realization of this desired price are $18, $11, and $88 million respectively in 1999, 2000, and 2001.

Using a base scenario of P1 = $0.55/lb and Q1 = 43.59 million pounds, simulation results indicate that at a producer price of 0.60, 0.65, 0.70, and 0.75 cents/lb, processors will demand 42.28, 40.97, 39.66, and 38.35 million pounds respectively. The government can purchase any excess supply above these quantities to maintain the set price. These quantity levels suggest a welfare loss to processors that increase with a price increase and a welfare gain by farmers. However, the net societal gain, though positive, declines with high prices.

An economic Analysis of Effluent Treatments in Hybrid Striped Bass Aquaculture
Yong-Suhk Wui and Carole Engle

The growth of aquaculture farming has resulted in increased scrutiny by regulatory agencies. The Environmental Protection Agency added aquaculture into the Effluent Limitation Guidelines (ELG) program in December 1999. The final rule is scheduled to be implemented in 2004. The ELG program bases its rulemaking effect on technology-based standards that are economically achievable.

While there have been a number of studies on effluent treatment in aquaculture, few studies have focused on the economic feasibility of the effluent treatments that have been evaluated and that might be adopted by farmers (Kouka and Engle).

The primary objective of this paper is to evaluate several effluent treatments that have been considered for Hybrid Striped Bass (HSB) farming. Farm-level impacts of proposed regulations were analyzed in terms of farm sizes and regions.

The scope of the paper is limited to pond production systems for grow-out of HSB foodfish. A Mixed Integer Programming (MIP) analytical model for HSB farming was developed focusing on maximizing profit derived from HSB production subject to the imposition of several different effluent treatment options. Survey data were collected from HSB farmers across the United States. Experimental data for effluent treatment were obtained from the literature and from on-going projects. The primary treatment options considered in this paper include no treatment, newly-constructed settling basins with Hydraulic Residence Time (HRT) of 1 and 20 days, existing ponds converted to settling basins with HRT of 1 and 20 days, constructed wetlands, fixed film filtering by honeycomb and brush filter media, not flushing pond water, not draining pond water, and circulating pond water. Settling basins and constructed wetlands entail high costs for farmers with high reduction in effluents. Filtering treatments incur high cost without much reduction in nutrient concentration in effluents. Not flushing water from the pond or not draining the pond annually reduces effluent volume. Reduction in the amount of water flushed or drained from the pond also decreases operating costs without any additional investment cost associated with adoption of the treatments. Effluent treatment options would increase production costs in average by $0.00-6.79/kg.

The main result of the MIP model is that no annual draining and not flushing the pond water are the best operational treatment. When a cost (tax) or effluent level standard regulations are imposed on effluent discharge, the model selected the no draining treatment. By not draining ponds, farms would minimize treatment cost by reducing effluent volume. However, additional work is needed on the long-term risks associated with not flushing or not draining HSB product ponds.

Evaluation of a New In-pond Mechanical Floating Grader for Food-sized Channel Catfish, Ictalurus punctatus
Jeremy Trimpey, David Heikes, and Carole Engle

Grading is a common practice in the culture of many fish species that involves separating a population of various sized fish into groups of similar size classes. There are a variety of techniques used to grade fish that have evolved through time with changes in technology and demand. Mechanical, box, vertical drag, and sock (net) grading have been adapted for use in grading channel catfish. While mechanical grading has been attempted for commercial catfish, the industry standard continues to be passive grading in socks (nets). However, it has been reported that the catfish industry loses over $100 million annually due to inefficient harvesting, grading, and transport. A new mechanical grader has been developed at the University of Arkansas at Pine Bluff to replace traditional methods of grading food-sized channel catfish.

Grading trials are underway to compare the performance and efficiency of the UAPB/Heikes grader with the traditional live car method (nets) at the UAPB Aquaculture Research Station and on commercial catfish ponds. The performance is measured as the kg of fish graded per minute. Efficiency between the two graders is accomplished by comparing overgrading (percent of sub-harvestable fish graded through with harvestable fish) and undergrading (percent of harvestable fish not graded). This will be accomplished by taking equivalent weights from a seine haul and grading those with each grading method. These trials will be held in three different ranges of water temperatures: cold (< 10° C), intermediate (14° to 26° C), and hot (> 27° C). During the UAPB trials three different size ratios (harvestable to sub-harvestable) of fish were stocked out in ponds: 75%/25%, 50%/50%, and 25%/75%. There will be three replicates of each trial at each temperature range with each ratio of fish sizes. The commercial trials will be replicated three times for each temperature range with the ratio of fish sizes that results from their farming practice. Figures 1 and 2 illustrate results from two trials held during the hot temperature range at UAPB.

2001 - 
Optimal Stocking Strategies of Catfish:

• Costs of producing various sizes of fingerlings
• Costs of producing various sizes of stockers from different fingerling sizes at different densities ( Steeve Pomerleau )
• Relationships of stocking density and feeding rate to production characteristics, water quality, and costs ( Brent Southworth )

Evaluation of the UAPB/Heikes In-Pond Floating Grader ( Jeremy Trimpey )

Economic Impact of U.S. Aquaculture:

• Economic impact of the catfish industry on Chicot County, Arkansas ( Aloyce Kaliba )
• Economic impact of the trout industry on Transylvania County, North Carolina ( Aloyce Kaliba )
• Farm-level economic impacts of postponed effluent treatment options on trout farms in North Carolina and Idaho

Economic evaluation of feeding varying levels of dietary protein every other day

Evaluation of potential to develop domestic markets for tilapia in Honduras and Nicaragua ( Ivano Niera )

Development of Rapid Market Assessment Tool ( Ivano Niera )

Business Plan Development for Tilapia in Kenya ( Ivano Niera )

2000 -
Comparison of the Costs and Benefits Associated with Understocking Different Sizes of Catfish Fingerlings in Growout Ponds

This study utilizes data from two fingerling production studies and one growout study to develop a data set of costs of producing 3,5,6, and 7 inch fingerlings with and without thinning. A third study developed estimates of key production parameters of catfish growout ponds when carryover fish were understocked with 3,5, or 7-inch fingerlings. Enterprise budgets and risk analyses were conducted for each study. These data will be used as coefficients in a multi-year dynamic linear programming model to explore the trade-offs associated with allocating pond space to producing and understocking different sizes of fingerlings.

Estimating Costs of Producing Stocker Catfish on Growout Farms

This study will follow the fingerling production studies and develop similar types of data to be incorporated into the mathematical programming model.

Economic Interactions Between Stocking and Feeding Practices in Intensive Catfish Production

This study estimated a Just-Pope production function to explore the economic interactions between stocking and feeding practices. It demonstrated that, although maximum yield may be obtained at higher stocking densities, the profit-maximizing stocking rate is between 6,000- 7,000 fingerlings/acre.

Farm-Level Economic Effects of Cormorant Predation on Farm-Raised Catfish

Enterprise budget analysis was used to compare net returns for farms with and without losses due to bird predation. Predation by cormorants was demonstrated to decrease yields by as much as 20% that results in negative returns on a farm that would have had positive net returns without cormorant predation. Additional 'work will utilize a two-year dynamic programming model to vary levels of bird pressure on catfish farms to evaluate relative effects on farm income and management strategies.

Determining the Profit-Maximizing Pond Size on Levee-Style Catfish Farms

A catfish production function was estimated using 1997 USDA survey data of U.S. catfish producers. A primal approach was employed to derive a net income function from the estimated production function, which was then used to estimate the profit-maximizing pond size. Results indicated that farms with larger ponds had greater variability of yield. The optimal pond size decreased as the number of ponds likely to be off-flavor increased. However, optimal pond size increased with farm size. Larger farms, with space for a greater number of ponds, could take more advantage of the lower costs associated with building slightly larger ponds.

Estimating the Economic Returns to the PD/A CRSP Research Investment in Thailand

Time-series secondary data on industry changes and technology transfer efforts will be used to measure aggregate changes in the supply of tilapia in Thailand. A survey of tilapia farmers who participated in on-farm trials of CRSP-developed technologies and those who did not participate will provide a basis to evaluate farm-level impacts of the adoption of CRSP
research technologies.

Development of Central American Markets for Tilapia Produced in the Region

Surveys were conducted of restaurants, supermarkets, and fish markets in all major urban and 8 small towns in Honduras that were based on a census of supermarkets and fish market vendors and a random sample of restaurants. Information was collected on product forms and sizes of fish species currently sold, current prices and volumes sold, current supply channels for different fish species and product forms,-and buyer attitudes towards farm-raised fish. Similar surveys will be conducted this summer in Nicaragua. Logit analyses will be conducted to determine those factors with the greatest effect on attitudes and preferences towards farm-raised tilapia and the likelihood that intermediate buyers will begin to purchase farm-raised tilapia products. This study will provide guidelines for development of a domestic market for tilapia in Honduras and in Nicaragua that would provide greater stability to the fledgling tilapia industry in the region.

Optimizing Stocking and Management Practices on Shrimp Farms in Honduras

A Target MOT AD linear programming model was developed to determine optimal stocking densities, length of production cycle, and stocking months to maximize net farm income on shrimp farms in Honduras. A 3-yr data set of pond production records from several farms was used to formulate the model. The model indicated that stocking at intermediate rates and adoption of new, low-water exchange rate technologies generated higher profits than the alternatives considered.

Fingerling Cost Budgets

.Two sets of budgets have been developed for production strategies with and without thinning. The budgets are developed for the production of 3, 4, 5, 6, and 7, inch fingerlings for both types of management strategies. These budgets should be available from the U APB Cooperative Extension Program in May.

Watershed Pond Catfish Production Budgets

A budget was developed for the production of foodsize catfish in watershed ponds in Arkansas. The budget unit was a 10-acre pond that was part of an 80-acre growout operation. This Fact Sheet should be available from the UAPB Cooperative Extension Program in April.