Flowing Water Fish Culture

Richard W. Soderberg

• Publisher: CRC Press
• Year: 2020
• Topic: Technology & Engineering
• eBook ISBN:
  9781000157505
• Subtopic: Biology
• Index: Technology & Engineering

Flowing Water Fish Culture provides an in-depth discussion of the husbandry of fin fish in a stream of water. It guides the reader through the technical considerations of intensive aquaculture, including fish growth rates, hydraulic characteristics of fish rearing units, oxygen consumption rates in relation to oxygen solubility and fish tolerance of hypoxia, and water reconditioning by reaeration and ammonia filtration. Unlike other publications that provide only general overviews on the subject, this text/reference offers specific details that will be useful in the actual design and operation of a facility. Problem sets at the end of each chapter provide ample opportunity to develop skills. The information in the book is valuable for those teaching, considering, or practicing aquaculture at intensity levels ranging from conventional single-pass trout hatcheries to closed aquaculture systems.

CHAPTER 1

Flowing Water Fish Culture

The practice of flowing water fish culture in the U.S. began in the mid-1800s in response to dwindling numbers of the native brook trout. The facilities were little more than fenced-off portions of streams resembling trout habitat. Eventually, all states with trout fisheries established fishery agencies and built hatcheries and the artificial reproduction and husbandry of salmonids was documented.

There are two basic considerations for the controlled growth of fish in a stream of water. First, the medium that supplies oxygen for respiration and flushes away metabolic waste is water, which has a low affinity for oxygen and occurs in finite quantities. This problem becomes obvious when aquaculture is compared to terrestrial animal husbandry in air, which contains a great deal of oxygen and is available in unlimited supply. Secondly, fish are cold-blooded and grow satisfactorily within rather narrow temperature ranges. Thus, water temperature determines which species, if any, may be produced. Warm-blooded animals, on the other hand, use food energy to maintain their optimum growth temperatures regardless of environmental temperature.

In the 1950s David Haskell, an engineer employed by the New York Conservation Department, first applied analytical investigation to the art of flowing water fish culture. Haskell’s quantitative approach to the definition of chemical and biological parameters affecting fish in confinement allowed fish culture to progress from an art to a science.

Haskell’s pioneering work resulted in the elucidation of five basic principles upon which our present understanding of flowing water fish culture is based:

1. At constant temperature, fish growth, in units of length, is linear over time until sexual maturity is approached.

2. The growth rate of fish, in units of length, is proportional to temperature. Therefore, if the growth rate at one temperature is known, the growth rate at another temperature may be predicted.

3. Feeding rates can be rationally calculated based on estimated food conversion, metabolic characteristics, and the anticipated growth rate.

4. The maximum permissible weight of fish that can be supported in a rearing unit is determined by the depletion of oxygen and the accumulation of metabolic wastes.

5. Oxygen consumption and metabolite production progress in proportion to the amount of food fed.

Based upon this framework, flowing water fish culture has become a quantitative agricultural science. The technology of that science is the subject of the chapters that follow.

CHAPTER 2

Fish Growth In Hatcheries

GROWTH RATES OF CULTURED FISH IN RELATION TO TEMPERATURE

Fish Growth Models based on Temperature Units

Haskell (1959) plotted trout growth rate against temperature in the range of 42 to 52°F, and found that they were linearly related with an intercept at 38.6°F (Figure 2.1). Growth does not cease at 38.6°F, but the intercept is necessary to establish the line from which growth is predicted. Haskell (1959) defined a temperature unit (TU) as 1°F over 38.6°F for 1 month. For example, if the monthly water temperature averaged 50°F, 50 – 38.6 = 11.4 TU would be available during that month. Haskell reported that approximately 21 TU were required per inch of trout growth in New York State hatcheries. In an experiment where brook trout were grown under conditions of “optimum care”, 16.2 TU were required per inch of growth (Haskell 1959), but Haskell doubted that trout could grow that fast under hatchery conditions. Modern hatcheries experience growth rates of approximately 17 TU/in., possibly due to improvements in hatchery management that have occurred since Haskell’s work. The actual growth rate, in temperature units required per length increment of growth, should be determined for each hatchery, species, and strain of fish.

The U.S. Fish and Wildlife Service (Piper et al. 1982) has adopted monthly temperature units (MTU), defined as the average monthly water temperature minus the freezing point of water. Therefore the MTU theory differs from Haskell’s TU model by assuming linear growth at temperatures cooler than 42°F. This procedure forces the growth line through the origin, which could result in a substantial error in growth rate estimation, especially for warm-water fish whose zero-growth intercepts are at higher temperatures than for salmonids. In Figure 2.2, Haskell’s (1959) data for brook trout are shown on a growth vs. temperature plot containing a regression line of best fit for the data when it is forced through the origin of the graph. It is evident that ignoring the zero-growth intercept compromises the accuracy of the model.

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Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Preface
• The Author
• Table of Contents
• Dedication
• Chapter 1 Flowing Water Fish Culture
• Chapter 2 Fish Growth in Hatcheries
• Chapter 3 Water Sources for Flowing Water Fish Culture
• Chapter 4 Fish Culture Rearing Units
• Chapter 5 The Solubility of Oxygen in Water
• Chapter 6 The Oxygen Requirements of Fish
• Chapter 7 Rearing Density and Carrying Capacity
• Chapter 8 Reaeration of Flowing Water
• Chapter 9 Ammonia Production and Toxicity
• Chapter 10 Water Recirculation
• Appendices
• Index