Production and economic effects of in-pond grading of channel catfish

Periodic grading and harvesting of fish has been shown to increase production of some species by removing larger fish throughout the growing season, reducing overall biomass, and increasing growth of smaller fish. Two two-year studies measured production and economic effects of the UAPB grader as compared to traditional live car grading and assessed effects of frequent harvesting and grading. Multi-batch production systems were used in both studies. In Study 1, fingerlings grew significantly better in ponds graded with the UAPB grader (0.97 g d⁻¹) as compared to the traditional live car (0.80 g d⁻¹) and resulted in 14% fewer under-sized (<0.57 kg) fish sent to the processor. In Study 2, increased frequency of harvest up to four harvests a year resulted in significantly fewer over-sized fish (>1.51 kg), more frequent receipt of revenue, and improved cash flow. Economic analysis showed that: (1) it was economically advantageous for catfish farmers to switch to the UAPB grader under a variety of farm size and processor dockage scenarios; and (2) increasing the frequency of harvest up to four harvests/year resulted in fewer over-sized fish, less dockage at the processing plant, improved cash flow, and more favorable economic outcomes.     

The economic feasibility of adoption of a new in-pond mechanical grader for food-sized channel catfish (Ictalurus punctatus)

An economic analysis of an in-pond horizontal floating bar grader for food-sized channel catfish was performed. Data from previously reported field trials were used to determine whether farmer adoption of this grader is economically feasible. Scenarios for four farm sizes (65, 130, 259, and 478 ha) were evaluated. Partial budget, payback period, net present value, internal rate of return, and Taguchi quality loss function analyses were used to quantify and compare economic losses due to deviation from the target fish size. Partial budget results indicated positive net revenue for all farm sizes. Net revenue increased with farm size, market price, and increased dockage penalties. Payback periods ranged from 0.1 to 2.0 years depending on the scenario. Net present values were positive and increased with increasing farm size. Estimated internal rates of return were higher than the current opportunity cost of capital and increased with increasing farm size. The value of the gain in quality from reducing size variation from use of the UAPB grader was estimated to range from $770 to $5575/year, depending on farm size. Producer adoption of the UAPB grader is economically feasible for the scenarios analyzed.     

Principal economic effects of cormorant predation on catfish farms

Substantial economic losses of farmed catfish to fish‐eating birds such as the double‐crested cormorant, Phalacrocorax auritus, continue to be reported on U.S. catfish farms. An economic analysis was conducted of the on‐farm effects of both the increased expenditures to scare fish‐eating birds from catfish farms and of the value of the catfish that were consumed by cormorants. A survey was conducted of U.S. catfish farmers in the Delta region of Mississippi and Arkansas, to obtain farm‐level data on expenditures to scare birds. Estimations of the lost revenue from catfish consumed by cormorants were developed from a concurrent study on cormorant distribution, abundance, and diet in the region. The economic effects of bird predation in terms of both fish consumption and management costs were evaluated across three farm sizes and nine catfish production practices. Catfish farmers spent on average $704/ha ± $394/ha to scare birds, making bird‐scaring costs one of the top five costs of raising catfish. The greatest cost components of scaring birds were manpower (39% of all bird‐scaring costs) and the variable and fixed costs of trucks used to scare birds (34% of all bird‐scaring costs). Losses were greater on hybrid than channel catfish fingerling ponds. Industry‐wide, the value of catfish losses averaged $47.2 million (range of $25.8–$65.4 million). Total direct economic effects (including both the increased costs to scare birds and the revenue lost from fish consumed by cormorants despite bird‐scaring attempts) averaged $64.7 million (ranging from $33.5 to $92.6 million). Profitability improved by 4% to 23% across the farm size/production strategies analyzed upon removal of the economic effects from bird predation, with greater effects occurring on smaller‐scale farms. One‐third of the farm size and production scenarios analyzed changed from being unprofitable to showing a profit in the absence of such negative economic effects associated with bird depredation. Overall, the combined effects of increased farm expenditures to scare birds from farms and the value of the catfish lost to predation by cormorants caused substantial negative economic effects on catfish farms.     

Economics of Intensively Aerated Catfish Ponds

The US catfish industry is evolving by adopting production‐intensifying practices that enhance productivity. Catfish producers have increased aeration rates over time, and some now use intensive rates of aeration (>9.33 kW/ha). Costs and production performance were monitored at commercial catfish farms using high levels of aeration (11.2–18.7 kW/ha) in Alabama, Arkansas, and Mississippi. A multivariate‐cluster analysis was used to identify four different management clusters of intensively aerated commercial catfish farms based on stocking density, size of fingerlings at stocking, and feed conversion ratios (FCR). Breakeven prices of hybrid catfish raised in intensively aerated pond systems were estimated to range from $1.86/kg to $2.17/kg, with the lowest costs associated with the second greatest level of production intensity. The two medium‐intensity clusters generated sufficiently high revenues for long‐term profitability. However, the least‐intensive and the most‐intensive clusters were economically feasible only when catfish and feed prices were closer to less probable market prices. Feed price, FCR, and yield contributed the most to downside risk. Intensive aeration in catfish ponds, up to the levels analyzed in this study, appears to be economically feasible under the medium‐intensity management strategies identified in this analysis.     

Comparative Economics of US Catfish Production Strategies: Evidence from a Cross‐sectional Survey

Understanding the effects of specific management strategies on yields and economic outcomes on commercial catfish farms could provide useful guidance to catfish farmers on the most profitable sets of production practices. Data from the U.S. Department of Agriculture–National Animal Health Monitoring System (USDA–NAHMS) 2009 survey of production practices on catfish farms in Alabama, Arkansas, Louisiana, and Mississippi were used to identify five clusters of catfish farms that use various stocking densities, channel versus hybrid catfish, different aeration levels, and utilize automated oxygen sensors. The lowest production costs ($1.96/kg) were found in cluster 1 and were followed in order of increasing costs per kilogram of clusters 2 and 4 ($2.16/kg) and cluster 5 ($2.73/kg); the highest cost corresponded to cluster 3 ($2.84/kg). The lowest risk levels corresponded to the clusters with the lowest production costs per kilogram of fish and the highest risk levels to the highest production costs. This analysis demonstrated that different types of management models can achieve similar levels of production costs ($/kg), and it appears that there is not one single economically optimum way to raise catfish. The key to least‐cost production is to balance the use of inputs, their associated costs, and the yield produced to achieve economic efficiency within the farm's overall business and management model.     

Technical efficiency of carp pond culture in South Asia: An application of a stochastic meta‐production frontier model

Abstract

A stochastic meta‐production frontier model is estimated to examine the inter‐country differences in levels of technical efficiency of semi‐intensive/intensive and extensive carp pond culture systems among the major carp producing countries in South Asia, namely India, Bangladesh, Pakistan, and Nepal. The mean technical efficiencies for semi‐intensive/intensive farms vary from 0.68 for Nepal to 0.79 for India, with an overall average of 0.75 and those for extensive farms vary from 0.48 for Bangladesh to 0.62 for Pakistan, with an overall mean of 0.57. Differences in efficiency levels are explained in terms of various farm‐specific and country‐specific factors by estimating a model for technical inefficiency effects. The adoption of recommended fish, water, and feed management practices is found to be critical for improved performance of carp producers. For each country, the study also compares the efficiency scores based on its own production frontier with those obtained from the meta‐production frontier.     

Technical efficiency of carp production in India: a stochastic frontier production function analysis

This paper aims to examine the levels and determinants of technical efficiency in carp pond culture in India. The stochastic production frontier technique involving the model for technical inefficiency effects is applied separately to samples of semi‐intensive/intensive and extensive carp producers interviewed during 1994–95. The results showed significant technical inefficiencies in carp production in India, especially among extensive farms. The mean technical efficiencies for semi‐intensive/intensive and extensive sample farms were estimated to be 0.805 and 0.658 respectively. By operating at full technical efficiency levels, the semi‐intensive/intensive farms could, on average, increase their production from about 3.4 Mt ha^?1 to 4.1 Mt ha^?1. Likewise, the extensive farms could increase their production from 1.3 Mt ha^?1 to 1.9 Mt ha^?1. Much of these efficiency gains would come from improvement in the adoption of recommended fish, water and feed management and monitoring practices. Besides expanding production area, the results indicated several other possibilities for increasing carp production in India by increasing yields per hectare, such as: (1) increased intensification of carp culture (i.e. moving from extensive to semi‐intensive or intensive systems); (2) improvement in technical efficiency at the farm level; and (3) technological progress. However, the realization of these potentials will depend on continuous efforts by the government in ensuring an adequate supply of inputs, technology transfer and development and adequate provision of research, extension and credit services in aquaculture.     

Cost of regulations on US catfish farms

Understanding the economic effects of regulations on US aquaculture farms provides insights into which compliance costs create the greatest compliance burden on farms. This can further guide strategies to improve the efficiency of regulatory frameworks and potentially reduce on-farm compliance costs while maintaining adequate oversight. This study estimated the regulatory compliance burden on US catfish farms as part of a national effort to quantify the cost of regulations on US aquaculture farms. Completed survey interviews of catfish farms in the major catfish-producing states covered 63% of the total US catfish production area. Total regulatory costs of the US catfish industry were estimated at $45 million annually. Lost farm revenues (measured as the value of lost production, the value of markets lost from regulations, and the value of business opportunities lost because of regulations) were estimated to be $35 million per annum. Catfish-producing states outside the Alabama/Arkansas/Mississippi region had the highest ($2856/ha) and Alabama the lowest ($1127/ha) regulatory costs per hectare among the surveyed states. The greatest regulatory cost burden on catfish farms ($18 million) was caused by environmental regulations related mostly to the management of federally protected piscivorous migratory birds, followed by labor regulations ($12 million), and taxes/insurance ($7 million). Regulatory costs ($/kg) were 2.6 times higher on smaller (<80 ha) farms relative to larger (>300 ha) farms. Attention is needed to identify alternative regulatory frameworks that provide the same degree of regulatory oversight but are more cost-efficient.     

The Economic Impact of the Catfish,Ictalurus punctatus,Industry on Chicot County,Arkansas

Abstract

This study analyzed the contribution of the catfish industry to the economy of Chicot County, Arkansas, using an input-output model. The objective was to quantify the economic contribution of the industry in terms of creating new dollars, jobs, and income to the local community. Mail surveys and personal interviews were used to collect data from catfish farmers, processors and other businesses related to the catfish industry. For farmers, the information solicited included production and marketing costs, sales and employment. Out of approximately 85 questionnaires administered to catfish farms, 44 usable questionnaires were obtained for a response rate of 52%. Businesses directly related to the catfish industry provided information on employment and sales and included: processors, seiners and haulers, pond builders, tractor and equipment dealers, and feed bin manufacturers. Other businesses with indirect ties to the catfish industry included: input supply companies, banks, fertilizer and chemical companies, auto shops, electricians, and bookkeeping firms. The survey data were used to modify the IMPLAN database for Chicot County to reflect the 2001 level of catfish production, processing and services available to support the industry. This database was then used to estimate the economic impact of the industry to the county's economy. In 2001, the 85 catfish farmers in the county operated about 7,859 ha (19,500 acres). The farm-gate value of catfish production exceeded $63 million. Employment on catfish farms was approximately 510. In addition, 59 other businesses depended on the catfish industry. Results indicated that total employment created in Chicot County by businesses directly or indirectly involved with the catfish industry was 2,665 jobs. This represented 48% of all employment in Chicot County. Total tax revenue (federal, state, and local taxes) generated from both direct and indirect catfish businesses was $22 million. Combined, the total economic impact of the catfish industry in Chicot County, including direct, indirect and induced effects, was over $384 million. The output multiplier calculated for live catfish production was 6.05. Thus, each $1 of earnings by catfish farms generated $6.05 total economic activity in the Chicot County economy. If current economic difficulties should result in contractions in catfish acreage in Chicot County by 10%, unemployment rates would increase by 2%. This study demonstrates the importance of the catfish industry to the economy of Chicot County.     

Evaluation of a Mechanical Grader to Separate Fingerling Channel Catfish,Ictalurus punctatus,into Length Groups

A Fischtechnik fingerling grader and bioscanner counter were evaluated for speed and accuracy in grading and counting channel catfish, "Ictalurus punctatus," fingerlings. Channel catfish fingerlings ranging in total length from 90 to 280 mm were graded into 110- to 140-mm, 140- to 170-mm, 170- to 200-mm and >200-mm length groups and counted. A sample of the fingerlings was manually separated through grader boxes with 109 mm (7/16 inch), 141 mm (9/16 inch) and 172 mm (11/16 inch) bar spaces to compare length variation within size groups with the mechanical grader. The accuracy of the bioscanner counter was tested by comparison with hand countintg. Fingerlings weighing 679 kg were mechanically graded and counted in 56 minutes, a rate of 12.1 kg/minute. Standard deviation for length within size groups was 10.9, 13.5, and 24.0 mm for the 109-mm, 141-mm, and 172-mm grader boxes, respectively; and 13.4, 12.6, 13.0, and 16.4 mm for the 110- to 140-mm, 140- to 170-mm, 170- to 200-mm and >200-mm mechanical grader length categories, respectively. Length variance within size groups was statistically lower for the mechanical grader compared with the box graders (P < 0.05). The bioscanner counter averaged a 5% overcount of channel catfish fingerlings compared with the manual count (P < 0.05).     

Economic analysis of alternative protein levels in channel catfish feeds

Abstract

Nutritional requirements for catfish (Ictalurus punctatus) feeds based solely on maximizing growth may not lead to the best economic performance. In addition, the choice of protein level may have important implications for dress‐out percentages in the processing sector. Processors may be able to send pricing signals to farmers to improve processing efficiencies. The objectives of this paper are to quantify the economic incentives to use different protein levels in catfish feeds and to investigate the possibility of processor incentives to affect these decisions. Data from research ponds, in conjunction with pricing and cost data, were used to quantify the changes in net returns associated with alternative protein levels. Both experimental results and estimates using commercial practices were developed. In addition these data were utilized in developing price premiums that might be implemented by the processing sector to provide incentives that would result in higher dress‐out percentages and thus greater processing efficiency. In a restricted‐feeding regime, selection of the higher protein feeds resulted in higher net returns, however, in a satiation‐feeding regime, lower protein levels resulted in higher net returns. Specifically, catfish enterprise profitability could be enhanced by feeding a 38% protein ration when fish are fed on a restricted basis whereas, in a satiation‐feeding regime profitability could be enhanced by feeding a 26% protein ration. Results indicate that the potential for a price premium policy that encourages a higher dress‐out percentage might be adopted in the future by the’ catfish processing sector as has been done in other meat processing industries.     

A comparison of new in-pond grading technology to live-car grading for food-sized channel catfish (Ictalurus punctatus)

Grading trials were performed in experimental and commercial catfish ponds to compare an in-pond horizontal floating bar grader to current live-car grading. Three replicate trials were conducted in experimental ponds at three different temperature ranges (warm, >26 °C; cool, 13–26 °C; cold, <13 °C) with catfish size groups stocked in ratios of either 75:25, 50:50, or 25:75 sub-marketable (<0.57 kg) to marketable fish (≥0.57 kg). Commercial pond trials were replicated three times at each temperature range with a fish size range typical of ponds ready to harvest. Stress experienced by fish during harvest and grading was measured by mean serum glucose and cortisol levels. Grading speed was greater (P < 0.05) with the UAPB grader (105–449 kg/min) than the traditional live-car grader (0.5–0.6 kg/min). The UAPB grader decreased (P < 0.05) the proportion of sub-marketable fish during all trials. In contrast, the live car did not reduce the proportion of sub-marketable fish with the experimental methods used in this study during commercial trials or in the 25:75 distributions during warm and cold temperature trials in experimental ponds. The UAPB grader returned an average two to four times (range of 2–52) more sub-marketable fish by weight to the pond than the traditional live car method. Glucose and cortisol levels in fish graded with the two technologies were not significantly different. The UAPB grader sorted fish more accurately, consistently, and quickly than the live car at all temperatures in both experimental and commercial trials.     

Gill-associated virus and its association with decreased production of Penaeus monodon in Australian prawn farms

Gill‐associated virus (GAV) was found to be associated with decreased prawn, Penaeus monodon, production when prawns from three farms (n = 45 ponds, 1800 prawns) were monitored for GAV over the production season using a graded RT‐nPCR. The grading system used was a visualization of either the outer or inner nested PCR products. Prevalence and loading of GAV were associated with disease severity. Ponds with a higher initial prevalence and a larger increase in GAV load over the production period suffered disease outbreaks. Ponds with low initial prevalence of GAV but a larger increase in prevalence and large increase in load over the production period suffered chronic disease with no disease outbreak identified, yet low production. However, the ponds with moderate to low initial prevalence of GAV with a low increase in prevalence and load of GAV over the production period incurred no disease outbreak and comparatively high production. Ponds with GAV prevalence greater than 75% at 1 month post‐stocking should be considered for termination as they have a high probability (95%) of having a disease outbreak. Emergency harvest when a disease outbreak occurs will significantly limit mortality losses.     

Farm-level costs of settling basins for treatment of effluents from levee-style catfish ponds

Compelled by pending regulatory rule changes, settling basins have been proposed as a treatment alternative for catfish pond effluents, but the associated costs to catfish farmers have not been estimated. Economic engineering techniques were used to design 160 scenarios as a basis for estimating total investment and total annual costs. For static-water, levee-style catfish pond facilities, sizing of settling basins is controlled by factors such as type of effluent to be treated, pond layout, size of the largest foodfish pond, number of drainage directions, scope of regulations governing effluents, and the availability of land. Regulations that require settling basins on catfish farms would increase total investment cost on catfish farms by $126–2990 ha⁻¹ and total annual per-ha costs by $19–367 ha⁻¹. More numerous drainage directions on farms resulted in the greatest increase in costs. While both investment and operating costs increased with larger sizes of foodfish ponds, costs per ha were relatively greater on smaller than on larger farms. For farms on which existing fish ponds would have to be converted to settling basins, over half of the cost was due to the production foregone and annual fixed costs of the pond. Requiring catfish farmers to construct settling basins would impose a disproportionately greater financial burden on smaller farms. The magnitude of the increased costs associated with settling basins was too high relative to market prices of catfish for this technology to be economically feasible.     

Technical efficiency of carp production in Pakistan

Abstract

The main objective of this study is to examine technical efficiency and its determinants in carp pond culture in Pakistan. A stochastic production frontier involving the model for technical inefficiency effects is applied separately to the samples of semi‐intensive/intensive and extensive carp producers. The mean technical efficiencies for semi‐intensive/intensive and extensive farms were 0.673 and 0.561, respectively. By operating at full technical efficiency the semi‐intensive/intensive farms could, on average, increase their production from 3.0 to 4.5 Mt/ha and the extensive farms from 2.6 to 4.6 Mt/ha. Much of these efficiency gains would come from the improvement in fish, water and feed monitoring and management. Besides improving technical efficiency, potential also exists for raising carp productivity through increased intensification and technological progress. However, the realization of these potentials will depend on continuous government support for adequate provision of inputs, market and infrastructure, technology transfer and development and extension and credit services to carp farmers.     

Current research on the use of plant‐derived products in farmed fish

Over the years, aquaculture has shown increasing development in terms of production. However, due to intensive farming practices, infectious diseases represent the main problem in fish farms, causing heavy economic losses. The use of antibiotics for controlling diseases is widely criticized for its negative impact, including selection of antibiotic‐resistant bacterial strains, immunosuppression, environmental pollution and accumulation of chemical residues in fish tissues. On the other hand, though vaccination is the most effective prophylactic method of preventing disease outbreaks, the development of effective formulations is often hindered by high production costs and the antigenic heterogeneity of the microbial strains. Recently, there has been increased interest in the possibility of using medicinal herbs as immunostimulants, capable of enhancing immune responses and disease resistance of cultured fish. Plant‐derived products seem to represent a promising source of bioactive molecules, being at the same time readily available, inexpensive and biocompatible. The aim of this article is to provide an overview of recent research dealing with the use of medicinal plants in aquaculture. Special attention is given to the information about the effects of plant extracts/products on fish growth, haematological profiles, immune responses and resistance to infectious diseases.     

Influence of Simulated Double‐crested Cormorant,Phalacrocorax auritus,Predation on Multiple‐batch Production of Channel Catfish,Ictalurus punctatus

The double‐crested cormorant, Phalacrocorax auritus, is considered the primary depredating bird species on commercially produced channel catfish, Ictalurus punctatus, in the southeastern USA. We simulated different levels of cormorant predation on losses at harvest and economic effects on channel catfish production in a multiple‐batch cropping system. We observed significant (P < 0.05) declines in catfish production at increasing levels of cormorant predation in this study. This decline was mitigated by increased individual growth of catfish at higher predation rates (i.e., lower catfish densities). This mitigating effect produced a non‐linear relationship with total kg of catfish harvested per pond resulting in a non‐linear incremental increase in breakeven price related to predation. Costs of production ($/kg) increased with increasing predation levels up to very high levels of predation with a cumulative maximum increase in breakeven price of $0.143/kg. These results indicate that losses at harvest due to cormorant predation occur immediately but are mitigated in part by compensatory growth of individual catfish. Losses due to cormorant predation in multi‐batch systems can be considerable, but there is not a 1:1 relationship between losses and kg of catfish harvested due to compensatory factors.     

PRODUCTIVE EFFICIENCY OF CATFISH FARMS IN CHICOT COUNTY,ARKANSAS

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.     

The economics of sutchi catfish (Pangasianodon hypophthalmus) aquaculture under three different farming systems in rural Bangladesh

This paper examines production costs and returns of sutchi catfish (Pangasianodon hypophthalmus) aquaculture under three different farming systems in Bangladesh. Based on the production technology, sutchi catfish farming is classified as extensive, semi‐intensive and intensive. Results showed that sutchi catfish farming is profitable irrespective of the level of intensification and in all three instances the cost of feed dominated the variable costs of production. The average annual production costs were estimated at US$5217 ha^?1 in intensive farming, while US$2694 ha^?1 in semi‐intensive and US$981 ha^?1 in extensive farming. Despite the higher production costs per hectare, the average annual net return was higher in intensive farming (US$3364), compared with semi‐intensive (US$2048) and extensive (US$1099) farming. The average annual production per hectare under intensive farming conditions (13 945 kg) was higher than semi‐intensive (7705 kg) and extensive (3380 kg) farming mainly due to higher levels of inputs, including seed, feed, fertilizer and labour. However, the Cobb–Douglas production function model suggests that inputs are inefficiently used in the intensive farming system. Conversely, there is enough scope to increase the production and income from the semi‐intensive and extensive farming systems by using more inputs.     

Characterization of intake and effluent waters from intensive and semi-intensive shrimp farms in Texas

Two commercial shrimp farms in south Texas were evaluated for influent and effluent water quality from June to October 1994. The intensive farm, Taiwan Shrimp Village Association (TSV) had an average annual yield of 4630 kg ha^?1 while the semi‐intensive farm, Harlingen Shrimp Farm (HSF), had a yield of 1777 kg ha^?1. The study had three objectives: (1) to compare influent and effluent water from the intensive and semi‐intensive shrimp farms, (2) to show which effluent water‐quality indicators exceeded allowable limits, (3) to indicate inherent problems in farms operated with water exchange and summarize how findings from this study led to changes in farms' management that limited potential negative impact on receiving streams. Water samples were collected and analysed twice a week for the TSV farm and once a week for the HSF farm. Samples were analysed for dissolved oxygen (DO), salinity, pH, ammonia‐nitrogen (NH₃‐N), nitrite‐nitrogen (NO₂‐N), nitrate‐nitrogen (NO₃‐N), total phosphorus (TP), total reactive phosphorus (TRP), five‐day carbonaceous biochemical oxygen demand (cBOD₅), total suspended solids (TSS) and settleable solids (SettSols). Most of the effluent constituents showed fluctuations throughout the sampling period often related to harvest activity. Effluent pH at TSV was lower than influent values but within the regulatory requirements set by Texas Commission of Environmental Quality (TCEQ), formerly known as Texas Natural Resource Conservation Commission (TNRCC). HSF effluent pH values were higher than its influent, but still within TCEQ limits. Effluent DO mean levels were generally below the regulatory daily mean requirement, with values at TSV often below those for influent. Effluent nutrient concentrations and net loads were generally higher at the intensive shrimp farm, with NH₃‐N mean concentrations above the daily mean set by the TCEQ on several occasions. Effluent TSS concentrations were higher than influent for both farms, with daily mean values above the TCEQ limit. The two farms presented similar TSS concentrations despite their different stocking densities. However, TSS total net load and net load per hectare were higher at the intensive farm. The semi‐intensive farm presented higher cBOD₅ concentrations and net loads despite its lower stocking density, with daily mean values above the TCEQ limit. The cBOD₅ net load at TSV presented negative values indicating higher load at the influent than at the effluent. Analyses showed no evidence of self‐pollution between influent and effluent at the two farms. The high feed conversion ratio (FCR) values (2.3 and 2.7 for the intensive and the semi‐intensive farm respectively) suggest that better feed management is needed to reduce nutrient and solid net loads release from the two farms. The data obtained from this study resulted in several modifications in design and management of the two farms that reduced the potential negative impact on receiving streams. A brief summary of the improvement in selected effluent water‐quality indicators at the intensive shrimp farm is provided.