Sustainable Biofloc Systems for Marine Shrimp

Tzachi Matzliach Samocha

• Publisher: Academic Press
• Year: 2019
• Print ISBN: 9780128180402
• eBook ISBN: 9780128182390
• Topic: Technology & Engineering
• Subtopic: Food Science
• Index: Technology & Engineering

Sustainable Biofloc Systems for Marine Shrimp describes the biofloc-dominated aquaculture systems developed over 20 years of research at Texas A&M AgriLife Research Mariculture Laboratory for the nursery and grow-out production of the Pacific White Shrimp, Litopenaeus vannamei. The book is useful for all stakeholders, with special attention given to entrepreneurs interested in building a pilot biofloc-dominated system. In addition to the content of its 15 chapters that cover topics on design, operation and economic analysis, the book includes appendices that expand on relevant topics, links to Excel sheets that assist in calculations, and video links that illustrate important operations tasks.- Presents the most recent trials on nursery & gross-out of L. vannamei- Includes a discussion of site selection, equipment options and water sources- Provides a step-by-step guides from tank preparation, to feeding and harvest

Chapter 1

Introduction

Granvil D. Treece Treece & Associates, Lampasas, TX, United States

Abstract

This chapter reviews the history of the biofloc concept. First mentioned in the 1960s, it was put into practice in the 1970s in aquaculture research by the French and in the United States. One of the first commercial applications was in 1988 in outdoor shrimp ponds in Tahiti. In 1997 a farm in Belize made major progress by achieving per-crop yields of up to 26 tons per hectare, along with lower food conversion ratios and a more stable growing environment. This naturally attracted industry attention and, with the Belize work as a model, biofloc culture continues to expand today. After a discussion of the pros and cons of the biofloc approach and a cost comparison of pond versus indoor culture, the chapter ends with a brief summary of the remaining content of this manual.

Keywords

Biofloc history; Recirculating aquaculture system; Biofloc technology; Indoor super-intensive shrimp culture; Outdoor shrimp biofloc; Zero water exchange; Biofloc advantages; Biofloc disadvantages

1.1 Development of Biofloc Technology for Shrimp Production

In the 1980s, most shrimp farms around the world were managed as extensive or semiintensive ponds with low postlarvae (PL) stocking densities (2–5 PL/m²), low yields (0.05–0.1 kg/m²), and high daily water exchange of up to 100% (but typically 10%–15%). Whenever a water quality problem arose—such as high levels of ammonia, low dissolved oxygen, dense algae blooms, or outbreaks of disease or parasitic organisms—it simply was flushed away by replacing a large fraction of poor-quality water with freshly pumped “clean” water. This practice exports water quality problems to the local environment, compromising the health of the surrounding aquatic ecosystem and the quality of intake water pumped by downstream aquaculture farms. This type of water quality management clearly is unsustainable.

Many of these flow-through systems gradually evolved toward smaller ponds (< 10 ha) with greater stocking densities (5–20 PL/m²) and greater yields (up to 0.3 kg/m²). This initially worked very well, but in 1988 Monodon baculovirus (MBV) infected shrimp farms in Taiwan. Other viral and bacterial diseases soon followed and this exacted a heavy toll on the worldwide shrimp aquaculture industry well into the 1990s. Some examples of noteworthy diseases include:

• • Taura Syndrome Virus (TSV) infected shrimp in ponds in the Taura River area of Ecuador and rapidly spread to other parts of the country.
• • White Spot Syndrome Virus (WSSV) started in Asia, arrived in the United States in 1995 and continues to cause problems in Mexico and many other countries.
• • Early Mortality Syndrome (EMS), also called Acute Hepatopancreatic Necrosis Disease (AHPND), began in China in 2009 and subsequently spread to Thailand, Vietnam, and Mexico.

This naturally prompted much greater attention to biosecurity, which now became a central concern of shrimp producers. A common response to controlling disease outbreaks was to add a secure holding reservoir to isolate disease-free broodstock. In addition, many farms began treating incoming water. In a dramatic break with contemporary practices, some established farms even undertook a major reconfiguration from traditional flow-through to water-reuse systems.

Over this same period, efforts were made to develop a viable marine shrimp farming industry in the United States. The emerging US industry was faced with overcoming a number of obstacles, foremost of which is a limited growing season. Significantly higher labor costs, higher energy costs, lack of suitable coastal land, and more stringent environmental regulations than in many shrimp producing countries also contributed to the competitive challenge.

With limited potential for development of year-round pond culture, research focused on cost-effective recirculating aquaculture systems (RAS) that operate at much higher biomass (> 5 kg/m³) and with minimal water exchange (< 10%/day). Because these systems use considerably less land and water than traditional ponds, they promised enhanced sustainability, greater biosecurity, and a regular supply of ultra-fresh, high-quality shrimp to domestic markets.

Achieving this objective motivated advances in a number of related areas, especially development of genetically improved lines of commercial shrimp species that are more tolerant of elevated stocking densities, advanced aeration equipment and techniques, efficient ammonia management procedures, and manufactured dry feeds specially formulated for use in high-density closed systems. Regarding genetically improved shrimp, many generations of selective breeding resulted in the production of specific pathogen free (SPF) stocks of Pacific White Shrimp Litopenaeus vannamei. This species has since risen to become the primary species cultured in ponds and closed systems around the world. These genetic lines have been a key reason for achievement of the much higher yields in modern aquaculture systems.

RAS may be classified in several ways. One that is useful for present purposes distinguishes between those that raise the target species separately from the bio-treatment processes and those in which the target species is raised in the same water volume as the bio-treatment organisms.

The first includes typical “clearwater” and IMTA (Integrated Multi-Trophic Aquaculture) systems, both of which maintain separate compartments for grow-out and removal of dissolved inorganic nitrogen. Clearwater systems use a traditional biofilter (Timmons and Ebeling, 2013) and IMTA uses macro...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Contributors
• List of figures
• List of tables
• Preface
• Acknowledgments
• Chapter 1: Introduction
• Chapter 2: Shrimp Biology
• Chapter 3: Biofloc
• Chapter 4: Water
• Chapter 5: Site Selection and Production System Requirements
• Chapter 6: System Treatment and Preparation
• Chapter 7: Water Quality Management
• Chapter 8: Nursery Phase
• Chapter 9: Grow-Out Phase
• Chapter 10: Shrimp Harvest
• Chapter 11: Waste Treatment and Disposal
• Chapter 12: Disease and Biosecurity
• Chapter 13: Economics of Super-Intensive Recirculating Shrimp Production Systems
• Chapter 14: Research and Results
• Chapter 15: Troubleshooting
• Glossary
• List of Abbreviations
• Appendix I: Water Quality Testing Procedures and Alternatives
• Appendix II: Microbiological Tests
• Appendix III: Sample Fixation With Davidson’s AFA Fixative, Storage, Labeling, and Transport
• Appendix IV: Water Quality Laboratory and Safety Procedures
• Appendix V: The Water-Quality Map
• Appendix VI: Technical Sheets
• Appendix VII: Excel Sheets and Forms—Summary
• Appendix VIII: Videos
• Index