Contents I Credits II Preface V 1. Soil and water quality considerations in shrimp farming 1 2. Site selection 33 3. Pond design and construction 49 4. Shrimp nutrition and feed management 65 5. Fertilization 93 6. Postlarvae Acclimation and stocking 109 7. Biosecurity in shrimp farming 123 8. Farm-raised shrimp good aquaculture practices for product quality and safety 169 9. Shrimp farm business mangement and economics 231 10. Management practices for reducing the environmental impacts of shrimp farming 265 I CONTENTS Editors: Maria C. Haws, Ph.D. Pacific Aquaculture and Coastal Resources Center University of Hawaii at Hilo 200 West Kawili St., Hilo, Hawaii, 96720, USA. Claude E. Boyd, Ph.D. School of Fisheries and Allied Aquacultures Auburn University Auburn, Alabama USA Authors: Claude E. Boyd, Ph.D. Auburn University Granvil Treece, Ph.D. Texas A&M University Sea Grant Program Carole R. Engle, Ph.D. University of Arkansas at Pine Bluff Diego Valderrama, M.Sc. University of Arkansas at Pine Bluff Donald V. Lightner, Ph.D. University of Arizona Carlos R. Pantoja, Ph.D. University of Arizona Joe Fox, Ph.D. Texas A&M University-Corpus Christi Dagoberto Sanchez ALCON, Inc. Steve Otwell, Ph.D. Aquatic Food Products Program University of Florida Sea Grant Program II Laura Garrido, M.Sc. Aquatic Food Products Program University of Florida Sea Grant Program Victor Garrido, M.Sc. Aquatic Food Products Program University of Florida Sea Grant Program Ron Benner, Ph.D. Aquatic Food Products Program University of Florida Sea Grant Program Illustrators and photo credits Steve Otwell Claude Boyd Granvil Treece Maria Haws Carlos Alemán Graphic Design: Alejandro E. Bermúdez O. (Central American University Press-UCA) Publication: Central American University Press-UCA Acknowledgements The editors and authors would like to thank the Consultative Groups of Honduras and Nicaragua for their review of the manual and technical contributions to the work. Members of the Groups include: Nicaragua Agnes Saborio M.Sc. Directora CIDEA-UCA Lic. Bernabela Orozco MAG-FOR Lic. Leyla Umaña MAG-FOR Ing. Diego Velazquez MAG-FOR Ing. Birmania Martinez MAG-FOR Lic. Alejandro Cotto MARENA Dr. Manuel Reyes Ponce ADPESCA Lic. Miguel Marenco ADPESCA Ing. Mario Callejas ANDA Dr. Alcides Gonzalez MINSA David Hughes Ph.D. AVE MARIA COLLEGE María Elena Vivas M.Sc. USDA Honduras Lic. Ana Gomez USDA Dr. Francisco Rodas SENASA (SAG) Lic. Gabriela Pineda DIGEPESCA (SAG) Lic. Rosa Duarte Planning Unit, DIGEPESCA (SAG) Lic. Eloisa Espinoza DIGEPESCA III Lic. Lourdes Moncada DIGEPESCA Dr. Daniel Meyer Panamerican Agriculture School, El Zaorano Ing. Marco Tulio Sarmiento Sub director DIGEPESCA Ing. Hector Corrales President ANDAH Ing. Alberto Zelaya General Director ANDAH Prof. Francisco Avalos Executive Director ANDAH P.M. Marvis Alvares Extension Agent ANDAH Dr. Jaime A. Araujo Director Pathology Laboratory Lic. Delia Martinez Director Water Quality Laboratory Specials thanks is also due to the following individuals for technical contributions and support during the development and production of this work: Dr. Gary Jensen (National Aquaculture Program Leader, USDA); Agnes Saborío (Director, CIDEA-UCA); Alberto Zelaya (General Manager, Honduran Association of Aquaculture Producers-ANDAH); Francisco Avalos (Executive Director ANDAH); Abelardo Rojas (CIDEA-UCA) and Francisco Orozco (ANDAH) (USDA Training Assistants), Ana Gomez and Maria Elena Vivas (FAS/ICD/USDA Coordinators). Seven anonymous reviewers also pro- vided valuable comments and suggestions. Final translation to Spanish was conducted by Emilio Ochoa Moreno, Rosa Matilde Ochoa, Marco Alvarez (Ecocostas, Ecuador) and Abelardo Rojas (CIDEA-UCA). Individual chapters were translated by Abelardo Rojas, Diego Valderrama, Carlos Pantoja, Oscar Zelaya, Oscar Blanco, Dagoberto Sanchez, Laura Garrido and Victor Garrido. Editors were assisted by the following individuals who are due special thanks for their support: Dr. Emanuel Polioudakis, Oscar Blancoand and Lisa Wedding. Finally, a number of individuals contributed to development of this work and their efforts are greatly appreciated: Steve Pomerleau (University of Arkansas at Pine Bluff), Martha Rowen (Auburn University) and Linda Nunan (University of Arizona). The staffs of CIDEA-UCA and ANDAH are also recognized for their contributions to this effort. IV hrimp farming is an evolving sector of agriculture that creates important economic opportunities in many rural communities plagued by under and unemployment. This water farming practice relies on the wise and responsible use of coastal natural resources and habitats. The long-term, local success of shrimp farming is also influenced by global market forces, consumer preferences and international food safety standards. Advances depend on accessibility of critical research, educational and laboratory ser- vices. Supportive policy, regulation and infrastructure at national and regional levels help creative a conducive business atmosphere. Today's challenges in shrimp farming partic- ularly impact small and medium producers because they are the least likely to benefit from, or have access to, the above mentioned elements that are preconditions for long- term viability of a natural resource based activity. In October, 1998, Hurricane Mitch caused extensive damage in several countries in Central America, in particular, Honduras and Nicaragua. In response to the widespread losses, the United States Congress appropriated funds to provide assistance in rebuil- ding damaged infrastructure and services in affected countries, with particular attention to Honduras and Nicaragua, where damage was most severe. Some funds were extend- ed to the U.S. Department of Agriculture's (USDA) Foreign Agricultural Service (FAS) through an interagency agreement with the U.S. Agency for International Development (USAID). Shrimp farming was one of numerous sectors in agriculture identified for Hurricane Mitch reconstruction support based in part on a needs assessment conducted by a USDA-FAS team. USDA responded with development of the Integrated Regional Shrimp Farming Support Program led by the USDA Cooperative State Research, Education and Extension Service and partner U.S. Land Grant universities with expertise and experi- ence in areas identified as priorities by diverse stakeholders in Mitch Hurricane-affected countries. This publication is a contribution from the USDA Integrated Regional Shrimp Farming Support Program and was developed by a coordinated effort involving multi-disciplinary expertise from a partnership alliance of seven U.S. universities. Each chapter address- es topics relevant to the long-term development of shrimp farming linked to sound farm- level management decisions that impact the environment, product quality and safety, profitability, and more. The chapters correspond to training modules presented in a relat- ed program component directed at training-the-trainers in Honduras and Nicaragua. The manual and related in-country training programs were designed to strengthen extension outreach capabilities to primarily benefit small and medium shrimp producers. Other pro- V Preface Preface S gram components enhanced disease diagnostic and water quality testing services in Honduras and Nicaragua. The manual provides technical and science-based information and state-of-art know- ledge that can be shared and disseminated broadly to benefit many persons associated with shrimp farming in Central America. The text was reviewed by multi-institutional con- sultative groups in Honduras and Nicaragua and underwent further peer review by con- tributing authors and other experts in the field. The manual is a reference for readers from which they can derive new knowledge and gain new skills to improve farming practices and management decisions that promote successful businesses and integration of pro- duction systems into sensitive, coastal ecosystems. We are especially pleased that the manual is published in both English and Spanish languages. Many individuals too numerous to mention by name deserve special thanks and appre- ciation for their contributions to this unique reference and in-country training activities. In particular, the individuals and teams associated with Auburn University, Texas A&M University, University of Arizona, University of Arkansas-Pine Bluff, University of Florida, University of Hawaii at Hilo, the Coastal Resources Center/University of Rhode Island and Ecocostas (Ecuador) are acknowledged for their contributions to the shrimp sector through this medium. Special gratitude is also owed to USDA's institutional partners, the National Association of Aquaculturists of Honduras (ANDAH) in Honduras, and the Center for Aquatic Ecosystems Research / Central American University in Nicaragua (CIDEA-UCA), both of which played significant roles in all in-country training activities. USDA's consultative groups in both countries guided all program activities and provided critical in-country assistance. The USDA-FAS field managers were instrumental in facilitating all technical assistance and training visits by USDA program team members. And lastly, Dr. Maria Haws is commended for her leadership in directing all aspects of planning, developing and publishing this manual. Gary Jensen Ph.D., Coordinator and Program Manager Integrated Regional Shrimp Farming Support Program U.S. Department of Agriculture Cooperative State Research, Education and Extension Service VI Preface S hrimp are delicate creatures that can be stressed by adverse environmental conditions in culture ponds. Shrimp that are stressed do not eat well, they are susceptible to di- sease, and they grow slowly. By maintaining good environmental conditions in ponds, shrimp farmers can enhance survival, feed utilization efficiency, and production of their crop. The environment in a shrimp pond consists primarily of the bottom soil and overlaying water, and the main environmental factors affecting shrimp are soil and water quality va- riables. Effluents from shrimp farms can cause adverse effects on coastal waters by increa- sing inputs of nutrients, organic matter, and suspended soils. However, negative impacts of effluents are less if ponds are well-managed and good soil and water quality conditions pre- vail in ponds. The purpose of this section is to provide information on soil and water quality in shrimp ponds. By reading this section, the shrimp farmer will be better prepared to understand the technical details that follow in other sections. This section also contains the basic principles related to good management practices for use in protecting pond soil and water quality and minimizing adverse impacts in natural ecosystems in the vicinity of shrimp farms. Warmwater shrimp species grow best at temperatures between 25 o C and 32 o C. Water tem- peratures are in this range throughout the year in most coastal areas in the tropics. In sub- tropical areas, water temperatures may fall below 25 o C for periods of several weeks or even several months, and shrimp will not grow well. Thus, two or more shrimp crops are usually produced annually in tropical areas. Only one crop per year can be produced in some sub- tropical areas, while in others, two crops are produced, but one crop will be limited by low water temperature. Temperature has a pronounced effect on chemical and biological processes. In general, bio- logical processes such as growth and respiration double for every 10 o C increase in temper- ature. This means that shrimp often will grow twice as fast at 30 o C as at 20 o C, and they will 1 Soil and water quality considerations in shrimp farming SOIL AND WATER QUALITY CONSIDERATIONS IN SHRIMP FARMING Claude E. Boyd Department of Fisheries and Allied Aquacultures Auburn University, Alabama 36849 USA WATER QUALITY Temperature INTRODUCTION use twice as much oxygen at the greater temperature. Therefore, dissolved oxygen require- ments of shrimp are more critical in warm water than in cooler water. The growth and res- piration of other organisms in shrimp ponds and chemical reactions in pond waters and soils also occur faster as temperature increases. Thus, environmental factors, and particu- larly water quality variables, become more critical to shrimp production as temperature increases. In ponds, heat enters at the surface and surface waters heat faster than deeper waters. Because the density of water (weight per unit volume) decreases with increasing tempera- ture above 4 o C, surface waters may become so warm and light that they do not mix with the cooler, heavier waters of deeper layers. The separation of pond waters into distinct warm and cool layers is called thermal stratification. In shrimp ponds, stratification often exhibits a daily pattern. During the day, the surface waters warm and form a distinct layer. At night the surface waters cool to the same temperature as the lower waters and the two layers mix (Figure 1). Figure 1. Thermal stratifi- cation in a relatively deep pool. Plants use carbon dioxide (CO 2 ), water (H 2 O), mineral nutrients, and sunlight to produce organic matter in the form of simple sugars (C 6 H 12 O 6 ) and oxygen (O 2 ) in photosynthesis. The summary reaction for photosynthesis is: Light energy + 6CO 2 + 6H 2 O C 6 H 12 O 6 + 6O 2 . The simple sugar molecules produced during photosynthesis by green plants represent nearly all of the energy available to living things. Both plants and animals depend upon pho- 2 Methods for improving shrimp farming in Central America Photosynthesis and Respiration tosynthetically-produced energy. The simple sugar molecules also are the building blocks for more complex organic compounds. Plants make starch, cellulose, proteins, fats, vita- mins, and other compounds from the sugars formed in photosynthesis. Plant tissues are comprised of these compounds, and plants use photosynthetically-derived sugar as an ener- gy source. Animals cannot produce organic matter. They must feed directly on plants or on animals that have fed on plants. In respiration, organic matter is combined with oxygen (oxidized) with the release of water, carbon dioxide, and energy. Plant and animal cells have the ability to capture some of the energy released through oxidation and to use it to do biological work. The rest of the ener- gy is lost as heat. From an ecological standpoint, respiration is the reverse of photosynthe- sis: C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O + heat energy When photosynthesis is progressing faster than respiration, oxygen will accumulate and car- bon dioxide will decline in pond water. This is the usual situation in a pond during daylight. At night, photosynthesis stops but respiration must continue day and night. Thus, at night oxygen declines and carbon dioxide increases. The food chain or food web in shrimp ponds (Figure 2) initiates with plants. In ponds the most desirable plants are phytoplankton. These organisms are microscopic algae that are suspended in the water. Algae often are green in color, but some may be blue-green, yellow, red, black, or brown. When pond water contains enough algae to be discolored, it is said to contain a "phytoplankton bloom", or more generally, a "plankton bloom". Algae can grow on the pond bottom where there is sufficient light for photosynthesis. The phytoplankton may be fed upon by microscopic creatures called zooplankton. Collectively phytoplankton and zooplankton are called plankton. Figure 2. Food chain in a shrimp pond. 3 Soil and water quality considerations in shrimp farming The plankton die and fragment to form dead organic matter (detritus) which is food for bac- teria, fungi, and other organisms. Detritus settles to the pond bottom; this enriches the soil with organic matter. The pond bottom supports a community of bacteria, fungi, algae, and small creatures called benthos. Aquatic insects are abundant in ponds and feed on plankton, benthos, or detritus. In the shallow areas of ponds with clear water, larger aquatic plants (macrophytes) may grow. However, plankton and benthos are continually dying, and there is usually an accumulation of dead organic matter on the pond bottom called detritus. The natural food of shrimp is mainly detritus, but they also eat plankton, benthos, detritus, aquatic insects, small fish and crustaceans, or some combination of these food organisms. In order to increase production in ponds, it is necessary to increase the amount of food. This can be done by improving conditions for production of phytoplankton, which, in turn, will increase the production of other natural food organisms. Usually, it is only necessary to add to ponds certain inorganic nutrients in the form of fertilizer to increase phytoplankton growth. However, natural food will not support high levels of shrimp production, and ma- nufactured feed is commonly added to ponds to allow more production than can be achieved in fertilized ponds (Figure 2). Phytoplankton is extremely important in the dynamics of dissolved oxygen concentrations in ponds. Phytoplankton growth is enhanced by nutrients from fertilizers and feeds. As a result of this, wide variations in dissolved oxygen concentration in water occur between night and day. Excessive phytoplankton blooms may lead to nighttime oxygen depletion and stress or mortality of shrimp. Water quality in ponds is to a large degree dominated by phytoplankton abundance, and the balance between photosynthesis and respiration. A large number of inorganic elements are required for plant growth. Most species require at least the following: carbon, hydrogen, oxygen, nitrogen, sulfur, phosphorus, chloride, boron, molybdenum, calcium, magnesium, sodium, potassium, zinc, copper, iron, and manganese. Diatoms also require silicon. Aquatic plants make oxygen during photosynthesis, and they obtain hydrogen from water. Carbon dioxide enters water from the air and from respiration of plants, bacteria, and ani- mals. The other elements enter ponds from the water supply, from minerals in the pond bottom, or in additions of fertilizer and feed. Some algae and bacteria are able to take mo- lecular nitrogen (N 2 ), which enters water from the air, and convert it to organic nitrogen in plant tissue. Nitrogen and phosphorus are more likely to limit phytoplankton growth than other nu- trients. Hence, fertilizers are added to ponds to supplement the natural shortage of nitrogen and phosphorus. After nitrogen and phosphorus, carbon is the next most common element that limits productivity in shrimp ponds. The availability of carbon is particularly low in acidic waters and in waters of high pH. Applications of agricultural limestone are used to neutralize acidity and enhance alkalinity and carbon availability in acidic ponds. The only 4 Methods for improving shrimp farming in Central America Dissolved and Particulate Substances [...]... is provided in Figure 3 Notice that salinity is clearly related to rainfall 7 Methods for improving shrimp farming in Central America Figure 3 Annual variability in rainfall and salinity in a shrimp pond in Ecuador Month Total Alkalinity The total concentration of bases in water expressed in milligrams per liter of equivalent calcium carbonate (CaCO3) is the total alkalinity Bases in water include hydroxide,... estuaries, and salinity may be stratified with depth in estuaries Marine shrimp, such as Litopenaeus vannamei and Penaeus monodon, can be cultured successfully in coastal ponds over the salinity range of 1 to 40 ppt However, salinities above 5 ppt are better for shrimp production, and most shrimp farmers prefer a salinity of 20 to 25 ppt in their ponds Annual variation in salinity of a shrimp pond in Ecuador... carbonate, but in most pond waters, bicarbonate and carbonate greatly exceed other bases in concentration The alkalinity should be above 75 mg/L in shrimp ponds Seawater has an average total alkalinity of about 120 mg/L Alkalinity may decline in waters of low salinity, and alkalinity often declines in ponds with acidic bottom soils The total concentration of all divalent cations in water expressed in terms... decreases with decreasing barometric (atmospheric) pressure Shrimp farms are located at sea level, and changes in barometric pressure in response to weather conditions are small This change in dissolved oxygen solubility resulting from pressure changes may be ignored in shrimp farming 12 Soil and water quality considerations in shrimp farming Table 3 The solubility of oxygen (mg/L) in water at different... use in the area and the types of pesticides used Only those pesticides used in the area could occur in the water A similar survey should be made for industrial chemicals Coliform organisms could be a problem by contaminating shrimp at harvest by contaminating the product during processing Coliforms in source water originate from fecal material of warm-blooded animals Fecal coliforms indicate contamination... denitrification in which certain bacteria convert nitrate to nitrogen gas This process usually occurs in anaerobic sediment Ammonia nitrogen can diffuse from pond water into the air, and this process is favored by high pH and wind blowing over pond surfaces Nitrogen also is lost from ponds in outflowing water and in shrimp at harvest Water entering ponds also contains phosphorus in dissolved inorganic phosphate... considerations in shrimp farming POND EFFLUENTS Water discharged from shrimp ponds during routine water exchange and for harvest contains nutrients, organic matter, and suspended solids These substances represent potential pollutants because they can cause water quality deterioration in receiving waters Thus, effluents are considered to be a major environmental problem in shrimp farming A literature... rapidly 17 Methods for improving shrimp farming in Central America Dissolved oxygen Figure 9 Changes in phyto plankton abundance before, during and after a phytoplankton die-off Figure 10 Influence of phytoplankton die-off on dissolved oxygen levels 18 Soil and water quality considerations in shrimp farming Mats of filamentous algae that develop on pond bottoms may, under certain conditions, float to the... alkalinity This results because of the buffering capacity afforded by the higher alkalinity Figure 5 Effects of alkalinity on diurnal pH variation time The direct influence of pH on shrimp is generalized below: Effect pH Acid death point No reproduction Slow growth Best growth Slow growth Alkaline death point 4 4-5 4-6 6-9 9-11 11 11 Methods for improving shrimp farming in Central America Where the pH of pond... (ppt) In brackishwater ponds, salinities vary with the salinity of the source water Estuarine waters may be similar in salinity to freshwater in the rainy season and have higher salinity in the dry season Some estuaries with restricted connections to the sea have salinities greater than ocean water in the dry season because ions are concentrated through evaporation Salinity decreases with distance upstream . variation in salinity of a shrimp pond in Ecuador is provided in Figure 3. Notice that salinity is clearly related to rainfall. 7 Soil and water quality considerations in shrimp farming Salinity Figure. alkalinity should be above 75 mg/L in shrimp ponds. Seawater has an average total alkalinity of about 120 mg/L. Alkalinity may decline in waters of low salinity, and alkalinity often declines in. resulting from pressure changes may be ignored in shrimp farming. 12 Methods for improving shrimp farming in Central America Dissolved Oxygen Solubility 13 Soil and water quality considerations in