Source: KENTUCKY STATE UNIVERSITY submitted to NRP
MODELING THE EFFECTS OF SUBSTRATE AMOUNTS AND CHARACTERISTICS ON PRAWN PRODUCTION AND POPULATION STRUCTURE
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
EVANS-ALLEN
Reporting Frequency
Annual
Accession No.
0186282
Grant No.
(N/A)
Cumulative Award Amt.
(N/A)
Proposal No.
(N/A)
Multistate No.
(N/A)
Project Start Date
Oct 1, 2000
Project End Date
Sep 30, 2005
Grant Year
(N/A)
Program Code
[(N/A)]- (N/A)
Recipient Organization
KENTUCKY STATE UNIVERSITY
(N/A)
FRANKFORT,KY 40601
Performing Department
AQUACULTURE
Non Technical Summary
The U.S. represents the largest market for shrimp in the world. However, domestic wild harvest are static, or decreasing, and aquaculture production of saltwater species has not developed substantially. Annually the U.S. trade deficit in shrimp products exceeds $2 billion. The purpose of this project is to intensify prawn production through the use of artificial substrate, and to quantify the relationships between stocking density, substrate inclusion, total production, and average weight mathematically. Also, to verify these models under commercial conditions.
Animal Health Component
100%
Research Effort Categories
Basic
(N/A)
Applied
100%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
30737221060100%
Knowledge Area
307 - Animal Management Systems;

Subject Of Investigation
3722 - Freshwater shrimp;

Field Of Science
1060 - Biology (whole systems);
Goals / Objectives
1) Evaluate the effects of differing amounts of added substrate on growth and population structures of prawns stocked at a set density. 2) Determine optimal substrate form, materials, and orientation. 3) Evaluate the effects of added substrate on the production and community structure of natural food organisms within ponds. 4) Develop empirical models of the effects and interactions of stocking size, stocking density, and amount of added substrate on the total production and average individual weight of prawns in ponds, then test these models under production conditions.
Project Methods
The approach of this research is to develop mathematical models to describe and predict production and population characteristics of prawns provided with substrate, develop efficient substrate units, materials, and placement, and evaluate the effect of added substrate on the production and availability of natural foods. These studies are designed to provide research based information in support of the establishment of commercial freshwater shrimp production in the region. Based on results of these studies a standard protocol will be developed and evaluated in a field trial of commercial scale ponds. Those data will be used to develop accurate enterprise budgets.

Progress 10/01/00 to 09/30/05

Outputs
This research program has encompassed a multistage, multiphase series of studies to intensify the production of freshwater prawns. It has incorporated the details of substrate inclusion, including color, materials, mesh sizes,etc as well as other aspects of production all the way from the hatchery, nursery (size grading), to production innovations (polyculture), to feeds and feeding, and live transport technologies. Research was primarily conducted in 0.04 ha experimental ponds that were initially stocked with 45-60 day nursed juveniles (0.25-0.50 g). The growing season was 110-120 days (early June - Mid- September and there were three replications (ponds) for each treatment evaluated. Size grading of juveniles prior to pond stocking had been shown to increase overall production. This management practice appears to separate an established size hierarchy and disrupt the re-establishment of aggressive interactions among individuals that can reduce collective rates of growth. Grading of juveniles prior to pond stocking significantly increased total production (2,988 kg/ha vs. 2,589 kg/ha) and average harvest weights (52 g vs. 45 g) (Tidwell et al., 2003). The effect of diet changes was another topic of investigation. Prawns are efficient grazers of natural foods and probably derive as much as 1/3 of their nutrition from natural food items, even when prepared diets are fed and the prawn biomass in the ponds is very high. However, some results suggested that at high biomasses, and large individual sizes, high quality, nutrient dense diets might be justified. Data generated here indicate that feeding a high protein penaeid diet throughout the production season was not superior to phase feeding, or the use of a cheaper sinking catfish feed. Just completed studies indicate that neither color, mesh material, nor mesh size of added substrate significantly influenced prawn production in tanks or ponds. The primary factor involved is the amount of substrate that is added. These finds have made the practical application of substrate technologies much more realistic, lowering material costs from approximately $2,000/ acre to less than $500/acre. When these different technologies are combined, current production rates (2,990 kg/ha) are almost 200 percent greater than the average production rates realized when this research was initiated (1,000 kg/ha). Equally important is that average harvest weight has not decreased at these higher production levels, rather increasing by approximately 45 percent. Substrate technologies appear extremely promising and appear to be additive with other production innovations. These technologies lend themselves to the relatively small pond (0.5 ha) sizes used in the temperate region. Preliminary budgets indicate that the substrate technology is extremely cost effective, especially since less expensive materials have proven to be equally effective.

Impacts
In recent years, the commercial production of the freshwater prawn has increased dramatically in the south central United States. This fledgling industry now encompasses over 2,000 acres and is estimated to involve over 500 farm families in 8 states. These studies are designed to provide practical research based information to support this new enterprise. Positive research findings have been field tested under a Yield Verification Program and results have been disseminated to the public via workshops, newsletters and presentations. Recent production improvements of over 200 percent have been achieved by combining individual research improvements into what we call Best Management Practice. Our goal is to translate these production numbers into commmercial scale improvements to ensure economically viable production.

Publications

  • Tidwell, J.H. and D.J. Bratvold. 2005. Utility of added substrates in shrimp culture. In: E. Axim, Editor. Periphyton: Ecology, Exploitation, and Management. CAB International Publishing Co., Wallingford, United Kingdom. Pp 247-268.
  • Refereed Journal Tidwell, J.H., S.D. Coyle, A. VanArnum, and C. Weibel. 2000. Production response of freshwater prawns Macrobrachium rosenbergii to increasing amounts of artificial substrate in ponds. Journal of the World Aquaculture Society, 31(3)452-458.
  • Book Chapters Tidwell, J.H. and L.D. DAbramo. 2000. Grow-out systems - culture in temperate zones. In Freshwater Prawn Farming: The Farming of Macrobrachium rosenbergii (Ed. M.B. New and W.C. Valenti). Blackwell Scientific. Oxford.
  • Tidwell, J.H., S.D. Coyle, A.VanArnum, C. Weibel, and S. Harkins. 2000. Growth, survival, and body composition of cage-cultured Nile tilapia, Oreochromis niloticus, fed pelleted and unpelleted distillers grains with solubles in polyculture with freshwater prawn, Macrobrachium rosenbergii. Journal of the World Aquaculture Society, 31(4)627-631.
  • Tidwell, J.H., S.D. Coyle, A. VanArnum, C. Weibel, and L. DAbramo. 2001. Use of artificial substrates to maximize production of freshwater prawns in temperate climates. World Aquaculture Vol. 32(3)40-42.
  • Tidwell, J.H., S.D. Coyle, A. VanArnum, L.A. Vitatoe, and M. McCathy. 2001. The effect of photoperiod on the nursery production of juvenile freshwater prawn, Macrobrachium rosenbergii. Journal of Applied Aquaculture. 11(4)41-48.
  • Tidwell, J.H., S.D. Coyle, A. VanArnum, and C. Weibel. 2002. Effect of substrate amount and orientation on production and population structure of freshwater prawns, Macrobrachium rosenbergii in ponds. Journal of World Aquaculture Society 33,63-69.
  • Coyle, S., J.H. Tidwell, A. VanArnum, L.A. Bright. 2003. A comparison of two feeding technologies, in freshwater prawns, Macrobrachium rosenbergii, raised at high biomass densities in temperate ponds. Journal of Applied Aquaculture, 14(1/2)125-135.
  • Coyle, S. S. Dasgupta, J.H. Tidwell, A. VanArnum, and L.A. Bright. 2003. Effects of stocking density on nursery production and economics of the freshwater prawn Macrobrachium rosenbergii. Journal of Applied Aquaculture, 14(1/2)137-148.
  • Xiong, S., Y.L. Xiong, S.P. Blanchard, B. Wang, and J.H. Tidwell. 2002. Tenderness evaluation of prawns (Machrobrachium rosenbergii) marinated in various salt and acid solutions. International Journal of Food Science Technology 37,291-296.
  • Coyle, S.D., J.H. Tidwell, and A. VanArnum. 2001. The effect of biomass density on transport survival of juvenile freshwater prawn, Macrobrachium rosenbergii. Journal of Applied Aquaculture, Vol. 11(3)57-63.
  • Dasgupta, S., and J.H. Tidwell. 2003. A breakeven price analysis of four hypothetical freshwater prawn, Macrobrachium rosenbergii, farms using data from Kentucky. Journal of Applied Aquaculture, 14(1/2)1-22.
  • Dasgupta, S., and S. Templeton. 2003. Comparing of Kentucky-grown freshwater prawn with marine shrimp & results of a taste test. Journal of the Kentucky Academy of Science, 64(2)128-132.
  • Tidwell, J.H., S.D. Coyle, L.A. Bright, A. VanArnum, C. Weibel. 2003. The effects of size grading and length of nursery period on growth and population structure of freshwater prawns stocked in temperate zone ponds with added substrates. Aquaculture. 218, 209-218.
  • Coyle, S., J.H. Tidwell, L.A. Bright, and D. Yasharian. 2004. Effect of different feeding strategies on production and economic returns for freshwater prawn, Macrobrachium rosenbergii, raised in earthen ponds in a temperate climate. Journal of Applied Aquaculture, 16(1/2)147-156.
  • Tidwell, J.H., S. Coyle, and S. Dasgupta. 2004. Effects of stocking different fractions of size-graded juvenile prawns on production and population structure during a temperature limited growout period. Aquaculture, 231,123-134.
  • Coyle, S.D., J. Tidwell, T. Beavers, L.A. Bright, and D. Yasharian. 2005. Comparative efficacy of anesthetics for the freshwater prawn, Macrobrachium rosenbergii. Journal of the World Aquaculture Society, 36(3)282-290.
  • Tidwell, J.H., L.R. DAbramo, S.D. Coyle, and D. Yasharian. 2005. Overview of recent research and development in temperate culture of the freshwater prawn (Macrobrachium rosenbergii) in the South Central United States. Aquaculture Research, 36 (3)264-277.
  • Yasharian, D.K., S. Coyle, J. Tidwell, and W.E. Stilwell, IV. 2005. The effect of tank coloration on survival, metamorphosis rate, growth, and time to reach the post-larvae stage in freshwater prawn Macrobrachium rosenbergii. Aquaculture Research, 36(3)278-283.
  • Extension & Trade Publications Coyle, S.D., J.H. Tidwell, A. VanArnum, and C. Weibel. 2000. The effect of hauling density on survival of juvenile freshwater prawn. Aquaculture Magazine.
  • Coyle, S.D., J.H. Tidwell, A. VanArnum, and C. Weibel. 2000. Effect of hauling density on survival of juvenile freshwater prawns. Kentucky Fish Farming Newsletter, 13(1)3.
  • Vitatoe, L.A., J.H. Tidwell, S.D. Coyle, and A. VanArnum. 2000. Controlling air breathing insects in freshwater prawn ponds. Aquaculture Magazine. November/December.
  • Vitatoe, L., J.H. Tidwell, S.D. Coyle, and A. VanArnum. 2000. Effectiveness of plant and animal oils for control of air breathing insects prior to stocking freshwater prawn ponds. Kentucky Fish Farming Newsletter, 13(1)2-3.
  • Tidwell, J.H. 2001. Freshwater prawns. Farm Pond Harvest 35(1) 18-26.
  • Coyle, S.D. and J.H. Tidwell. 2002. U.S. research studies feeding technologies for freshwater prawns. The Global Aquaculture Advocate.
  • Coyle, S. & J. Tidwell. 2002. Effect of different feeds and feeding technologies on prawn production. Kentucky Aquatic Farming Newsletter, Vol. 15(2). Pg. 3.
  • Coyle, S.D. and J.H. Tidwell. 2003. Effect of different feeds and feeding technologies on prawn production. World Aquaculture Magazine, Vol. 34(2)51-53.
  • Tidwell, J. and S. Coyle. 2002. Research Update - Prawns. Kentucky Aquatic Farming Newsletter, Vol. 15(4)5. Yasharian, D., B. Durborow, J. Tidwell, and S. Coyle. 2002. Freshwater prawn production in Kentucky: direction for the industry based on 2002 production data. Kentucky Aquatic Farming Newsletter. Vol. 15(4)3.
  • Yasharian, D., S. Coyle, J. Tidwell, and C. Boyd. 2002. Gypsum to Control pH in Shrimp Ponds. Kentucky Aquatic Farming Newsletter. Vol. 15(2)2.
  • Coyle, S.D. and J.H. Tidwell. 2003. Effect of feeds, feeding and natural foods on freshwater prawn production. pp: 533-539 In T.P. Lyons and K.A. Jacques, Editors. Nutritional Biotechnology in the Feed and Food Industries. Nottingham University Press, Nottingham, United Kingdom.
  • Dasgupta, S. and J.H. Tidwell. 2003 Freshwater prawn culture at Kentucky State University, An economic analysis. pp 28-31 In P. Perschbacher, Editor.
  • Yasharian, D., B. Durborow, J. Tidwell, and S. Coyle. 2003. Freshwater prawn production in Kentucky. Aquaculture Magazine, 29(5)17-18.
  • Yasharian, D., S. Coyle, J. Tidwell, and L.A. Bright. 2004. Evaluation of transport technologies for live hauling adult freshwater prawn Macrobrachium rosenbergii. Kentucky Aquatic Farming 17(1):5-6.
  • Yasharian, D., S. Coyle, and J. Tidwell. 2004. Hatchery and nursery production of the freshwater prawn Macrobrachium rosenbergii in temperate climates. Global Aquaculture Advocate. August 2004.
  • Coyle, S.D., L.A. Bright, D. Yasharian, and J.H. Tidwell. 2005. A comparison of pond production of juvenile prawns stocked as 30 and 60 day nursed juveniles. Kentucky Aquatic Farming newsletter, spring 2005, pp. 5-6.
  • Coyle, S.D., D. Yasharian, J. Danaher, and J.H. Tidwell. 2005. Comparison of polyculture production of freshwater prawn Macrobrachium rosenbergii with Nile tilapia Oreochromis niloticus stocked as either free ranged or confined in cages. Kentucky Aquatic Farming newsletter, spring 2005, pp. 3-4.
  • Tidwell, J.H. and S. Coyle. 2005. Freshwater prawn feed management. Global Aquaculture Advocate, Vol. 7(6)58-59.
  • Yasharian, D., S.D. Coyle, J. Tidwell, A. Caporelli, N. Skudlarek, and J. Kimpara. 2005. Kentucky prawns bound for the big apple. Kentucky Aquatic Farming newsletter, Spring 2005, pp. 2-3.


Progress 01/01/04 to 12/31/04

Outputs
A previous study demonstrated that the polyculture of tilapia in cages floated in prawn ponds actually increased prawn production 28% and improved water quality. This was due to the tilapia grazing down the phytoplankton populations. Research in 2004 was conducted to evaluate whether the tilapia might have even more impact if they were not confined in cages and were able to graze freely in all areas of the ponds. The experiment was conducted in nine 0.04 hectare ponds and consisted of three treatments with three replicates each. Control ponds contained only prawns. Caged polyculture ponds contained prawns plus two cages of tilapia (4,800 tilapia/ha). The third treatment was polyculture with the same number of tilapia, but not confined in cages. All ponds contained circulators and substrate. All ponds were stocked with top-graded, 60-day nursed juvenile prawn (0.93 g) at 40,000/ha. Polyculture treatments used monosex male tilapia (90 g). Tilapia were fed a 32% protein floating pellet once a day to satiation while the prawn were fed a 32% protein sinking prawn diet twice daily based on a feed chart. Water quality parameters including total ammonia-N, un-ionized ammonia nitrogen, and nitrite nitrogen were analyzed three times weekly. Dissolved oxygen, temperature, and pH were analyzed twice daily. Plankton samples were taken on a fortnightly basis. Tilapia and prawn were sampled every three weeks to determine growth rates. At harvest there were no significant differences in treatments in terms of water quality. When tilapia were confined in cages they had no significant impact on prawn weight, total production, or survival. However, when the same number of tilapia were stocked unconfined, they had a significant negative impact on prawn weight, production, and survival. There was no significant difference in tilapia growth or survival when cultured in cages or unconfined. Treatment differences are due to the fact that unconfined tilapia were able to reproduce. Resulting young-of-the-year tilapia were able to compete directly with the freshwater prawns for food, negatively impacting prawn growth and survival. Prawn/tilapia polyculture is a very viable alternative. However, tilapia should be confined in cages to control reproduction and allow ease of harvest.

Impacts
In recent years, the commercial production of the freshwater prawn has increased dramatically in the south central United States. This fledgling industry now encompasses over 500 farm families in 8 states. These studies are designed to provide practical research based information to support this new enterprise. High pH levels have been a recurring problem in prawn production ponds. This research demonstrates a biological method for reducing pH levels while producing a second salable crop.

Publications

  • Coyle, S., S. Dasgupta, J.H. Tidwell, A. VanArnum, L.A. Bright. 2003. Effects of stocking density on nursery production and economics of the freshwater prawn Macrobrachium rosenbergii. Journal of Applied Aquaculture, 14(1/2):137-148.
  • Osunde, I.M., S. Coyle, J. Tidwell. 2003. Acute toxicity of copper to juvenile freshwater, Macrobrachium rosenbergii. Journal of Applied Aquaculture, 14(3/4):71-79.
  • Tidwell, J.H., S. Coyle, S. Dasgupta. 2004. Effects of stocking different fractions of size-graded juvenile prawns on production and population structure during a temperature limited growout period. Aquaculture, 231:123-134.


Progress 01/01/03 to 12/31/03

Outputs
The freshwater prawn has become a commercially important culture species in the southeast United States. Regional prawn farmers have at times experienced problems with high pH in grow-out ponds due to excessive algal blooms, which can lead to significant prawn mortality. Nile tilapia are known to graze on phytoplankton and may be able to potentially thin algal blooms. The objective of this study was to determine the effect of two densities of caged tilapia on the water quality, growth, survival, and production of freshwater prawn verses prawn monoculture. The experiment was conducted in nine 0.04 hectare ponds and consisted of three treatments with three replicates each. Control ponds contained only prawns. Low density polyculture ponds contained prawns plus two cages of tilapia (4,942 tilapia/ha) and high density polyculture four cages of tilapia (9,884 tilapia/ha). All ponds contained circulators and substrate. Each pond was stocked with top-graded, 60-day nursed juvenile prawn (0.93g) at 69,000/ ha. Monosex male tilapia (115.6 g) were stocked in 1 m3 round cages at 100/m3. Tilapia were fed a 32 percent protein floating pellet once a day to satiation while the prawn were fed a 32 percent protein sinking prawn diet twice daily based on a feed chart. Water quality parameters including total ammonia-N, un-ionized ammonia nitrogen, and nitrite nitrogen were analyzed three times weekly. Dissolved oxygen, temperature, and pH were analyzed twice daily. Chlorophyll-a and BOD were analyzed monthly. Plankton samples were taken on a fortnightly basis. Tilapia and prawn were sampled every three weeks to determine growth rates. At harvest average prawn weight was significantly higher in polyculture treatments (43 g) than in monoculture (36 g). Prawn production was significantly higher in the four cage polyculture (2,760 kg/ha) than in the two cage polyculture (2,403 kg/ha), which was significantly higher than monoculture (2,156 kg/ha). Total pond production (prawn and tilapia) in high density polyculture averaged 10,723 kg/ha. Results indicate afternoon pH readings were significantly lower at the surface and pond bottom of both polyculture treatments when compared to control ponds. Total ammonia-nitrogen concentrations were significantly higher in polyculture treatments than in control ponds. However, un-ionized ammonia concentrations did not differ significantly by treatment, due to the lower pH.

Impacts
In recent years, the commercial production of the freshwater prawn has increased dramatically in the south central United States. This fledgling industry now encompasses over 500 farm families in 8 states. These studies are designed to provide practical research based information to support this new enterprise. High pH levels have been a recurring problem in prawn production ponds. This research demonstrates a biological method for reducing pH levels while producing a second salable crop.

Publications

  • Tidwell, J.H., S.D. Coyle, L.A. Bright, A. VanArnum, C. Weibel. 2003. The effects of size grading and length of nursery period on growth and population structure of freshwater prawns stocked in temperate zone ponds with added substrates. Aquaculture. 218:209-218.
  • Coyle, S.D., J.H. Tidwell, A. VanArnum, L.A. Bright. 2003. A comparison of two feeding technologies in freshwater prawns macrobrachium rosenbergii, raised at high biomass densities in temperate ponds. Journal of Applied Aquaculture. 14(1/2):125-135.


Progress 01/01/02 to 12/31/02

Outputs
Research conducted this reporting period evaluated the effect of prawn production intensification on production economics, water quality, social structure, and benthic macroinvertebrate populations during the pond growout phase of the freshwater prawn. Three stocking densities were evaluated: 35,000 (low level of intensification), 48,000 (moderate intensification level), and 61,000/ha with added substrate (Best Management Practices, BMP). Survival was higher for the BMP treatment compared to the moderate level. Survival at the low density was not different from other treatments. The increased stocking densities and feed rates used in the BMP treatment resulted in higher overall concentrations of total ammonia and nitrite; however the measured values were not sufficient to cause negative impacts on prawn growth or survival. We are in the process of benthic macroinvertebrate samples for treatment comparison. Economic data suggest that the BMP treatment was the most economical treatment. Although the inputs and therefore risks are greater for BMP ponds, they appear to be biologically sustainable and economically justified.

Impacts
In recent years, the commercial production of the freshwater prawn has increased dramatically in the south central United States. This fledgling industry now encompasses over 2,000 acres and is estimated to involve over 500 farm families in 8 states. These studies are designed to provide practical research based information to support this new enterprise. Positive research findings will be field tested under a Yield Verification Program and results will be disseminated to the public via workshops, newsletters and presentations. Although our research is not complete, recent production improvements of over 200% have been achieved by combining individual research improvements into what we call Best Management Practice. Our goal is to translate these production numbers into commercial scale improvements to ensure economically viable production.

Publications

  • Tidwell, J.H., S.D. Coyle, A. VanArnum, and C. Weibel. 2002. Response of freshwater prawns to different amounts and orientations of artificial substrate. Journal of World Aquaculture Society. 33:63-69.
  • Bright, L.A., S.D. Coyle, A. VanArnum, and J. Tidwell. 2002. Laboratory evaluation of the relative effectiveness of plant and animal source oils for control of notonectidae in fish ponds. North American Journal of Aquaculture, 64(3):210-211.


Progress 01/01/01 to 12/31/01

Outputs
Research conducted during this reporting period evaluated the impacts of size grading of nursed juveniles prior to pond stocking and the effects of extending the nursery period from 60 to 120 days. Three treatments were evaluated: 60 day ungraded juveniles, 60 day graded juveniles, and 120 day graded juveniles. Extending the nursery period, and the resulting stocking weight, did not significantly improve total production or average individual weight. The high graded animals increase total production and average weight approximately 30 percent compared to the controls. We also evaluated the relative growth of the different fractions (upper and lower) of graded populations relative to ungraded controls and found that the lower grade performed slightly inferior to the ungraded controls. However, when the relative proportions from the high grade and low grade were recombined there was approximately a 20 percent production increase compared to the ungraded controls.

Impacts
In recent years, the commercial production of the freshwater prawn has increased dramatically in the south central United States. This fledgling industry now encompasses over 2,000 acres and is estimated to involve over 500 farm families in over 8 states. These studies are designed to provide practical research based information to support this new enterprise. Positive research findings will be field tested under a Yield Verification Program and results will be dessiminated to the public via workshops, newsletters and presentations. Although our research is not complete, recent production improvements of over 100% have been achieved by combining research improvements into what we call Best Management Practice. Our goal now is to translate these production numbers into the field to ensure economically viable production.

Publications

  • Coyle, S.D., J.H. Tidwell, and A. VanArnum. 2001. The effect of biomass density on transportsurvival of juvenile freshwater prawn, Macrobrachium rosenbergii. Journal of Applied Aquaculture, Vol. 11(3):57-63.
  • Tidwell, J.H., S.D. Coyle, A. VanArnum, L.A. Vitatoe, and M. McCathy. 2001. The effect of photoperiod on the nursery production of juvenile freshwater prawn, Macrobrachium rosenbergii. Journal of Applied Aquaculture. 11(4) 41-48


Progress 01/01/00 to 12/31/00

Outputs
Evaluate the effects of differing amounts of added substrate on growth and population structures or prawns stocked at a set density. 2) Determine optimal substrate form, materials, and orientation. 3) Evaluate the effects of added substrate on the production and community structure of natural food organisms within ponds. 4) Develop empirical models of the effects and interactions of stocking size, stocking density, and amount of added substrate on the total production and average individual weight of prawns in ponds, then test these models under production conditions. The approach of this research is to develop mathematical models to describe and predict production and population characteristics of prawns provided with substrate, develop efficient substrate units, materials, and placement, and evaluate the effect of added substrate on the production and availability of natural foods. These studies are designed to provide research based information in support of the establishment of commercial freshwater shrimp production in the region. Based on results of these studies a standard protocol will be developed and evaluated in a field trial of commercial scale ponds. Those data will be used to develop accurate enterprise budgets.

Impacts
The U.S. represents the largest market for shrimp in the world. However, domestic wild harvest are static, or decreasing, and aquaculture production of saltwater species has not developed substantially. Annually the U.S. trade deficit in shrimp products exceeds $2 billion. The purpose of this project is to intensify prawn production through the use of artificial substrate, and to quantify the relationships between stocking density, substrate inclusion, total production, and average weight mathematically. Also, to verify these models under commercial conditions.

Publications

  • No publications reported this period