Culture and Capture of Fish in Chinese Reservoirs Li Sifa and Xu Senlin Published by Southbound and the International Development Research Centre ISBN 983-9054-11-2 140 pages 18x26cm US$22.00 Click here to order with Visa and MasterCard credit cards

China produces more freshwater fish than any other country in the world, but most information on culture techniques has focused on the now famous Chinese system of fish culture in ponds. In view of current predictions for the construc tion of new reservoirs throughout Asia, reservoir fisheries hold considerable potential to increased fish production in this region.

Since the end of World War II, China has developed a considerable amount of knowledge about fish production in reservoirs. An estimated 1.44 x 106 ha of reservoirs are used for fishery production in China, and average annual production is 214 kg/ha. In th e post-war period, an extensive production system for reservoir fisheries has evolved. However until now, much of this information has not been available in English. This text is the culmination of several years of translation, editing, and revision. It is based on a Chinese text first published by the authors in 1988.

Reservoir fisheries involves the management of fish resources, fish culture, and fish capture. Reservoir fisheries is a new industry in China compared with pond fisheries, which is more than 3,000 years old, and lake fisheries which is over 1,000 years old. Fish culture was first practised in China in the Dongqianhu Reservoir, which was built in 744 in Zhejiang Province. However, it is only within the last 30 years that fish farming in reservoirs has become popular.

To increase fish production in reservoirs, increased priority must be given to: reasonable stocking rates of large-size fingerlings, installation of reliable and effective fish barriers, effective elimination of harmful organisms, enhancement of economic fishery resources, application of effective fishing gear and methods, development of cage and pen fish-culture based on local conditions, and development of integrated fish-farming systems (e.g., fish-livestock-forestry or fish-agriculture-livestock).

CONTENTS

Acknowledgements
Foreword
Preface

PART 1 RESERVOIRS

Chapter 1 Hydrological and Physicochemical Characteristics of Reservoirs

Morphology

Common terminology and parameters

Types of reservoir

Classification by morphology
Classification by size

Hydrology

Water level, storage capacity, and surface area

Flow rate
Sedimentation

Physicochemical characteristics of reservoir water

Water temperature
Transparency
pH
Dissolved gases
Nutrients

Chapter 2 Natural Food Organisms

Phytoplankton

Zooplankton

Detritus and bacteria

Periphyton

Benthos

Aquatic Macrophytes

Chapter 3 Development of Fish Resources

Formation and development of the natural ichthyofauna

Riverine fishes
Lacustrine fishes
Migratory fishes

Manipulation of fish fauna in reservoirs

Dominant species
Development of fish fauna

Biology of economically importance species

Silver carp
Bighead carp
Common carp
Crucian carp
Grass carp
Grass bream
Black bream
Wuchang fish
Xenocyprinae
Mud carp
Elopichthys bambusa
Erythroculter ilishaeformis
Erythroculter mongolicus
Erythroculter dabryi
Snakehead
Mandarin fish
Catfish
Opsariichthys bidens
Pike (Esox reicherti)
Hemiculter leucisculus

Chapter 4 Assessment of Fish Productivity in Reservoirs

Biological production process

Transformation of matter and energy in reservoirs
Biological production processes

Classification of trophic level of reservoir

Assessment of fish production

Factors influencing fish productivity

Environmental factors
Species composition and population structure
Human activity

Principal methods to evaluate fish productivity

Evaluation based on area of surface water
Vegetation and soil quality of catchment area
Morphoedaphic index (MEI)
Biomass of food organisms
Primary productivity

Factors to be considered when estimating fish productivity

PART II FISH CULTURE IN RESERVOIRS

Chapter 5 Culture of Large-size Fingerlings

Fingerling culture in cages

Advantages and disadvantages

Reservoir and site selection

Food sources
Flow rate of water

Installation of cages

Dimensions of cages

Fingerling production in cages

No-feeding culture
Feeding culture

Routine management

Timely cleaning
Inspection of cages
Prevention of losses because of floods and typhoons

Fingerling culture in coves

Selection of coves

Fishery concerns
Construction engineering concerns

Design of coves

Net-fenced coves
Dam-blocked coves

Fingerling production in coves

Predator elimination
Management
Escape
Harvest of fingerlings

Fingerling culture using barnyard grass and rice

Artificial propagation of reservoir populations of silver carp and bighead carp

Maturation of brooder fish
Natural spawning grounds

Use of brooder population

Artificial insemination
Transportation of brooders
Induced breeding and artificial insemination
Hatching

Chapter 6 Stocking

Stocking strategy

Species selection

Stocking density and ratio

Empirical method
Theoretical calculation

Stocking size and quality of fingerlings
Stocking time and place

Transportation of fingerlings

Modes of transportation
Factors affecting survival during transportation

Intensive culture in small reservoirs

Silver carp and bighead carp as the principal species
Grass carp and common carp as the principal species
Integrated fish farming in small reservoirs

Culture of food fish in net cages

Culture of silver carp and bighead carp without artificial feeding

Culture of common carp and tilapia with feeding

Culture of common carp
Culture of tilapia
Culture of luxury species

Fish culture in tailwater

Fish culture in running water ponds

Water source
Design of running water ponds

Fish culture in irrigation canals

Fixed cages
Floating or movable cages
Culture of rainbow trout

Chapter 7 Management of natural fish resources

Control of predators and low-value species

Common predators and their impact

Endanger stocked fishes
Lengthening the food chain and decreasing
Fish productivity

Types of predators

Pursuing predators
Ambushing predators
Parasitic predators

Population dynamics of predators

Conditions favouring the development of predators as the dominant species
General trends in predator populations

Control of predators

Eliminate the source
Destroy spawning conditions
Chemical control and catching
Control of small low-value fishes

Enhancement and protection

Transformation and enrichment of ichthyofaunal

Populations
Temperature
Salinity
Food

Improvement of spawning conditions

Protection of spawning grounds
Installation of artificial nests

Increase natural food sources

Reasonable harvests

Fishing intensity
Size limits
Control of fishing season

PART III BARRIERS AND HARVESTS TECHHNIQUES

Chapter 8 Barriers

Types of barriers

Fence

Bamboo (wooden) fence
Bamboo baskets
Wire fences

Barrier nets
Electric screen

Design of barrier nets

Design principles

Selection of the section of the reservoir to be impounded
Flow rate
Depth of the barrier net
Size and species of fish
Mesh size
Net twine

Design procedures

Survey of barrier site
Area of barrier net
Dimensions of nets
Twine consumption
Type and dimension of lines
Resistance of barrier net
Net weight of barrier net in the water
Floating and sinking forces of a barrier net
Applied forces on the head line and foot line
Applied forces on anchoring devices

Installation of barrier net

Cutting and stitching of net panels
Installation of floats and sinkers
Installation of cover net
Installation of bottom net

Debris filter
Boat-passing device

Case study

Primary design features
Efficiency

Electric screens

Reactions to electrical stimulation

Initial reaction
Directive reaction
Narcotic reaction

Design of pulse screen

Site selection
Geometrical and electrical parameters of electrode array

Construction of LD-1 electric screen

Insert type
Slanted strut type
Hanging type

Operating experience

Chapter 9 Harvesting pelagic fish species

Migration habits of silver carp and bighead carp

Joint fishing method

Principles and practice

Types of fishing gear

Driving gear
Blocking net
Fixed filter net

Design and installation of principal fishing gear

Blocking net
Trammel net
Fixed filter net
Dimensions of nets
Mesh size, twine thickness, and hanging coefficient
Installation of a fixed filter net

Fishing methods

Formulation of a fishing plan
Fishing techniques
Seine net

Use and structure

Fishing method
Shooting
Hauling

Chapter 10 Harvesting demersal fish species

Relevant biology of common carp

Gill net for common carp

Net structure

Fishing method

Shooting
Hauling

Motorized trawl

Net structure

Wing net
Cover net (square)
Body net and bag
Gusset and flapper

Main parameters

Estimation of pulling force
Determination of hanging coefficients
Horizontal and vertical spreading of the net opening
Buoyancy and weight of sinker line
Tension on tow line

Fishing method

Chapter 11 Harvesting predatory species

Relevant biology of major predators

Pelagic predators
Demersal predators

Fishing gear and methods

Polyethylene gill net for Elopichthys bambusa

Net structure
Installation methods
Fishing methods

Cage weir

Structure
Construction and installation
Fishing methods

References
List of Fish Species
List of Reservoirs