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Pacific oyster farming – A practical manual

Preparation of this document

This manual focuses on the practical techniques and cultivation strategies needed to successfully farm the Pacific or cupped oyster, Crassostrea gigas . Oysters are a highly nutritious food source and, requiring no manmade feed or fertilizer to grow, are an example of sustainable, low carbon aquaculture production that can make an important contribution towards the goal of feeding an expanding global population in a responsible and environmentally friendly fashion. The manual provides a detailed and exhaustive list of the components necessary to construct each of the cultivation systems that are described within its pages, and a step-by-step guide on the assembly and installation process. The manual also guides the user as to how to create and execute a management and monitoring plan, ensuring that all the necessary cultivation procedures are implemented in accordance with the production schedule. This guide is not intended to be a scientific paper and if the reader requires a more in depth understanding of the organism itself, there are many other publications available that can provide this, some of which are listed in the further reading section at the end of the manual. This publication includes many technical illustrations, instructional drawings, tables and photographs to ensure that all the subjects examined within its pages are elucidated. Where necessary, a clear visual representation of each topic, technique or piece of equipment is included to assist the reader in understanding what is being explained in the text. Supplementary details of the subject matter can be found in the appendixes at the end of the manual that elaborate further on some of the more technical matters described in each chapter. Hatchery seed production is not included in this manual but a list of reference publications that describe this process are listed in the further reading at the end of the manual if the reader wishes to research this phase of the production cycle further. Clear definitions of all the technical terms used in the text are included in the glossary and should be consulted when clarification is required. This document is one of three technical guides on shellfish culture produced as part of a project funded and implemented by the Food and Agriculture Organization of the United Nations (TCP/DRK/3803) in enhancing coastal livelihoods and food security in the Democratic People’s Republic of Korea.

Abstract

The purpose of this manual is to give the reader a foundation of practical knowledge regarding all aspects of Pacific oyster cultivation. It is targeted at new entrants to the market wishing to establish a farm, and existing operators who wish to develop their farms and explore new cultivation techniques. The methodologies described can be applied to both low-tech, low budget, small-scale farming operations and to high-tech, big budget, industrial-scale aquaculture production enterprises. This guide focuses on the functional expertise and technical equipment required to construct and manage an operational farm in the diverse environmental and physical locations in which they can be situated, from the initial stages of finding and selecting a suitable site, to the conclusion of the first production cycle and harvesting the crop. The manual contains a brief introduction which describes the relevance of the species with regards to global aquaculture production figures and how it can form an important part of future food production strategies. Chapter 2 describes the anatomy and biology of Crassostrea gigas and gives an indication as to the environmental conditions in which the species thrives as well as the pathologies and predators that can result in poor health leading to potential mortalities. Quality assessment parameters are also discussed with regards to desirable attributes when selling final product into the market and what is necessary to be aware of when considering consumer safety. Chapter 3 deals with all aspects of undertaking a survey of potential oyster farming sites and what data should be collected and examined in order to both assess a site’s suitability, but also which areas are best suited to different cultivation techniques. After this, Chapter 4 introduces the main farming techniques that will be described in detail in the following chapters, which includes off-bottom cultivation, on-bottom cultivation, and suspended cultivation, and also gives details of some of the most common cultivation equipment necessary to undertake these operations. The techniques and strategies necessary to procure seed oysters and how to develop them through the nursery stage are also introduced. This includes the basic principles of upwelling, which then leads into Chapter 5, which provides a detailed description of how to build and operate one particular example of a Floating Upwelling System (Flupsy) which is suitable for use in remote but sheltered conditions. A section on the best practices to be adopted when handling and transporting oysters is also included in this chapter. Chapters 6, 7 and 8, constitute the main body of the manual and provide an in depth look into the three major cultivation techniques that this guide concentrates on: “Farming with trestles and bags in the intertidal zone”, “On-bottom cultivation in the intertidal or subtidal zone” and “Offshore long-line cultivation”. These represent three of the most common farming techniques adopted in a multitude of locations and, although other techniques are utilised, are responsible for the majority of oyster production around the globe. In each chapter, all aspects of the farming process are explored including site selection, farm design, farming practices and main constraints. Finally, the manual finishes with some suggestions for further reading, a glossary and appendixes which includes information on food safety in regard to bivalve molluscs and some further details about cupped oyster production figures.