Elsevier

Aquaculture

Volumes 350–353, 20 June 2012, Pages 117-129
Aquaculture

Review
The importance of selective breeding in aquaculture to meet future demands for animal protein: A review

https://doi.org/10.1016/j.aquaculture.2012.04.008Get rights and content

Abstract

Aquaculture is the fastest growing food production industry, and the vast majority of aquaculture products are derived from Asia. The quantity of aquaculture products directly consumed is now greater than that resulting from conventional fisheries. The nutritional value of aquatic products compares favourably with meat from farm animals because they are rich in micronutrients and contain high levels of healthy omega-3 fatty acids. Compared with farm animals, fish are more efficient converters of energy and protein. If the aquaculture sector continues to expand at its current rate, production will reach 132 million tonnes of fish and shellfish and 43 million tonnes of seaweed in 2020. Future potential for marine aquaculture production can be estimated based on the length of coastline, and for freshwater aquaculture from available land area in different countries. The average marine production in 2005 was 103 tonnes per km coastline, varying from 0 to 1721 (China). Freshwater aquaculture production in 2005 averaged 0.17 tonnes/ha, varying from 0 to close to 6 tonnes per ha (Bangladesh), also indicating potential to dramatically increase freshwater aquaculture output. Simple estimations indicate potential for a 20-fold increase in world aquaculture production. Limits imposed by the availability of feed resources would be lessened by growing more herbivorous species and by using more of genetically improved stocks.

Aquaculture generally trails far behind plant and farm animal industries in utilizing selective breeding as a tool to improve the biological efficiency of production. It is estimated that at present less than 10% of aquaculture production is based on genetically improved stocks, despite the fact that annual genetic gains reported for aquatic species are substantially higher than that of farm animals. With an average genetic gain in growth rate of 12.5% per generation, production may be dramatically increased if genetically improved animals are used. Importantly, animals selected for faster growth have also been shown to have improved feed conversion and higher survival, implying that increased use of selectively bred stocks leads to better utilization of limited resources such as feed, labour, water, and available land and sea areas.

Highlights

► We demonstrate existence of vast potential for increased aquaculture production. ► The largest potential for aquaculture lies in the marine environment. ► Selection responses in aquaculture species are higher than for conventional livestock. ► More use of genetically improved stocks may dramatically increase aquaculture output. ► Genetically improved stocks are critical for better utilization of limited resources.

Introduction

Humanity's greatest problem has been to secure food suitable to meet nutritional needs. It has been said that, ‘Without food, nothing else matters’ (Warwick and Legates, 1979). Many areas of the world currently lack adequate food supplies. Of the 2009 population of 6.7 billion people, 960 million were undernourished (Johnson, 2009), and the human population is predicted to increase to 9.1 billion by 2050 (Diouf, 2009). This population growth, combined with increased average income and increased urbanization with associated shifts in diet towards more nutritious and higher quality foods, is expected to result in almost a doubling of the demand for food (Diouf, 2009). This illustrates that a serious food crisis already exists, and is expected to increase in coming years. It is an enormous task to increase food production to meet the future demand.

When discussing the food crisis Kutty (2010) points out that our long-term perspectives about providing adequate food for the world's growing population have to change dramatically. The same author further states that, ‘The land-based food production systems, despite further expansion and intensification, are limited. We have to turn to water and not too much to land for additional food production, through available sustainable technologies and evolving new innovations, which would ensure our food and nutritional security’. According to Duarte et al. (2009) neither land-based nor marine-based food production alone will suffice to feed humanity in the future, an intelligent integration of marine- and land-based food production is required to meet this essential goal. Marra (2005) discussed the importance of mariculture in the future and argued that a major change in food production is required by moving the production of animal protein from land to the ocean. However, Waggoner (1994) expresses an optimistic view on future plant production: ‘If average fields in the world sixty or seventy years hence, when we are likely to number ten billion, yield as much food as today's potato fields in Ireland, wheat fields in France, or corn fields in Iowa, large portions of the land currently in crops can revert to Nature’. This view is supported by Gjølberg (2010), who argues that many countries can increase agriculture production considerably. He points out that much of the potentially rich agricultural land is actually underutilised, and argues that the solution is to pass on knowledge about fertiliser use and modern agronomy techniques.

With this in mind it is of interest to discuss the role of aquaculture in meeting the future demand for animal protein. Today 53% of fish and shellfish production takes place in freshwater (FAO, 2009) which constitutes only 1% of the globe's surface, while the very large areas covered by sea- and brackish water are currently only marginally utilised. An important part of increasing the future aquaculture production is to improve the biological productivity of farmed species of fish, shellfish (crustacean and molluscs) and seaweeds. The role of selective breeding will therefore be discussed. Investments in well planned and managed breeding programs are unique, because genetic gains obtained in such programs are eternal and cumulative. They are never ‘used up’, and never ‘wear out’ (Weller, 2006).

Quantitative genetics and selective breeding represent a young field of science, and the technology uptake in the aquaculture sector has been slow compared with plant and farm animal industries. Reasons for this are likely to be many and not easily explained. In this review we demonstrate the potential for large genetic improvement in aquatic species and we make some estimations and predictions about the scope for future increased aquaculture production through greater utilisation of genetically improved stocks.

Section snippets

Status of aquaculture production

Asia dominated the world's production of fish and shellfish in 2008 (producing 88% by volume), followed by the Americas, Europe, Africa and Oceania (4.6%, 4.5%, 1.8% and 0.3% respectively, Table 1). Likewise, nearly all seaweed production also takes place in Asia, with China alone producing 2/3 of the world's production (FAO, 2009).

As shown in Table 2, aquaculture production has nearly doubled, and the value of aquaculture products has more than doubled, over the last ten years.

A high

Fish and shellfish for human consumption: comparison with meat from farm animals

Although their nutritional value may vary, fish and shellfish are in general good sources of nutrients. Fish is easily digestible and contains a well balanced amino acid composition. Fish are regarded as healthy, not only because of the content of the omega-3 fatty acids but also because of their content of micronutrients (Centre of Excellence Seafood and Health (CESSH), 2011; Luten, 2008) and amino acids.

The muscle composition of fish and beef is similar, with the exception of the fat content

Efficiency of fish production

Fish are generally more efficient converters of feed into meat than warm blooded animals, due to higher maintenance and respiratory costs for the latter. On average only 2% of the consumed energy is used for biomass production in homeotherms compared with 17% in poikilotherms (Smith, 1992). In Table 7 the retention of energy and protein for Atlantic salmon is compared with pigs and poultry, which are the most efficient meat producing land-based farm animals. The genetically improved salmon had

Growth in aquaculture production

For several years the catch of fish and shellfish has been stable at around 90 million tonnes per year, and the harvest of seaweeds at approx. one million tonnes (FAO, 2009). FAO (2008) stated that ‘The maximum wild capture fisheries potential from the world's oceans has probably been reached’. For aquaculture the situation is different. Aquaculture production of fish and shellfish has grown by an average of 7.7% per year over the last decade (FAO, 2009). No other food production sector shows a

Current status of breeding programs

Modern breeding programs were initiated for plants around 1900 based on the findings from the pioneering hybridization experiments by Mendel (1866), and the same theoretical principles were for the first time applied to terrestrial farm animals some 15 years later (Hagedoorn, 1950). Well-designed breeding programs have since revolutionised the biological efficiency of plant and livestock production through the development of genetically improved, high yielding seed stocks. Aquaculture generally

Interaction between farmed and wild stocks

As domestication and selective breeding of a species progresses, key characteristics of farmed animals will differ more and more from wild stock. Some animals are likely to escape from farms and could interact with the wild stock. The ability of selectively bred escapees to survive, outcompete wild fish and reproduce will no doubt depend on the wild populations, the local environment and ecology, the timing and extent of release(s) and the extent of genetic divergence of the selected stock from

Increased production

From a production point of view there is much to be gained by producing stock which is genetically improved. Basically all applied breeding programs have improvement of growth rate as a major goal, and most results on selection response for growth cited in this paper were obtained when selection targeted growth rate as the only trait. It is expected that gain for the individual traits in selective breeding programs will be reduced as the number of traits under selection is increased.

In order to

Concluding discussion

Early in 2011 FAO declared that ‘1 billion people live in chronic hunger’, which means that there is an ongoing food crisis in the world. Moreover, the world population is expected to increase rapidly in coming years, and Diouf (2009) points out that strong growth in income and urbanization will occur, with associated shifts in diet structure towards more nutritious and higher quality foods. This implies that the demand for animal protein will increase at a high rate. The prospect of future food

Acknowledgements

We are indebted to Nofima for their financial contribution and to our colleagues for continued and stimulating support. In particular we would like to thank Dr. Bjarne Gjerde, who took the initiative to recommend this review, and Dr. Jørgen Ødegård for their valuable contributions.

References (135)

  • K. Gunnes et al.

    Selection experiments with salmon. IV. Growth of Atlantic salmon during two years in the sea

    Aquaculture

    (1978)
  • K. Gunnes et al.

    A genetic analysis of body weight and length in rainbow trout reared in sea water for 18 months

    Aquaculture

    (1981)
  • G.B. Havenstein et al.

    Growth, livability, and feed conversion of 1957 versus 2001 broilers when fed 1957 and 2001 broiler diets

    Poultry Science

    (2003)
  • M. Henryon et al.

    Genetic variation for growth rate, feed conversion efficiency, and disease exists within a farmed population of rainbow trout

    Aquaculture

    (2002)
  • D.J.S. Hetzel et al.

    Response to selection and heritability for growth in the Kuruma prawn, Penaeus japanicus

    Aquaculture

    (2000)
  • M.G. Hussain et al.

    Comparative performance of growth, biochemical composition and endocrine profiles in diploid and triploid tilapia Orechromis nilioticus L

    Aquaculture

    (1995)
  • M.G. Hussain et al.

    Stock improvement of silver carp (Barbodes gonionotus Bleeker) through several generations of genetic selection

    Aquaculture

    (2002)
  • A. Isaksson

    Salmon ranching: a world review

    Aquaculture

    (1988)
  • J. Jonasson

    Selection experiments in salmon ranching: I. Genetic and environmental sources of variation in survival and growth in freshwater

    Aquaculture

    (1993)
  • L. Kangmin

    Rice–fish culture in China: a review

    Aquaculture

    (1988)
  • C. Langdon et al.

    Yields of cultured pacific oysters, Crassostrea gigas Thunberg, improved after one generation of selection

    Aquaculture

    (2003)
  • A.O. Maluwa et al.

    Genetic parameters and genotype by environment interaction for body weight of Oreochromis shiranus

    Aquaculture

    (2006)
  • L.R. McKay et al.

    Genetic variation for spinal deformity in Atlantic salmon, Salmo salar

    Aquaculture

    (1986)
  • J.M. Myers et al.

    Genetics and broodstock management of coho salmon

    Aquaculture

    (2001)
  • K.G. Neely et al.

    Comparison of growth, feed intake, and nutrient efficiency in a selected strain of coho salmon (Oncorhynchus kisutch) and its source stock

    Aquaculture

    (2008)
  • R. Neira et al.

    Genetic improvement in Coho salmon (Oncorhynchus kisutch). I: Selection response and inbreeding depression on harvest weight

    Aquaculture

    (2006)
  • J.A. Nell et al.

    Evaluation of the progeny of second-generation Sydney rock oyster Saccostrea glomerata (Gold 1850) breeding lines for resistance to QX disease Marteilia sydneyi

    Aquaculture

    (2003)
  • J.A. Nell et al.

    Studies on triploid oysters in Australia. 1. The farming potential of triploid Sydney rock oysters Saccostrea commercialis (Iredale and Roughley)

    Aquaculture

    (1994)
  • M.Y. Abeywardena et al.

    Role of omega-3 longchain polyunsaturated fatty acids in reducing cardio-metabolic risk factors

    Endocrine, Metabolic & Immune Disorders Drug Targets

    (2011)
  • Anonymous

    Survey on the breeding practices in the European aquaculture industry

  • Barlow, R., 1983. Benefit–cost analyses of genetic improvement program for sheep, beef cattle and pigs in Ireland. PhD...
  • H.B. Bentsen et al.

    Genetic interactions between farmed and wild fish, with examples from Atlantic salmon case in Norway

  • Bjørkli, J., 2002. Protein and energy account in salmon, chicken, pig and lamb. (Protein og energirekneskap hos laks,...
  • K. Bondary

    Response to bidirectional selection for body weight in channel catfish

    Aquaculture

    (1983)
  • B. Carlin

    Salmon tagging experiements

  • Centre of Excellence Seafood & Health
  • T. Chopin

    Progression of the Integrated Multi-Trophic Aquaculture (IMTA) concept and upscaling of IMTA system towards commercialization

    Aquaculture Europe

    (2012)
  • S.L. Clifford et al.

    Genetic changes in an Atlantic salmon population resulting from escaped juvenile farm salmon

    Journal of Fish Biology

    (1998)
  • S.L. Clifford et al.

    Genetic changes in Atlantic salmon (Salmo salar) populations of northwest Irish rivers resulting from escapes of adult farm salmon

    Canadian Journal of Aquatic Science

    (1998)
  • I. Csavas

    The status and outlook of world aquaculture

  • G.M. Dannevig

    Apparatus and methods employed at the Marine Fisheries Hatchery at Flødevig, Norway

    Bulletin of the U.S. Bureau of Fisheries

    (1910)
  • G. Dickerson

    Efficiency of animal production—molding the biological components

    Journal of Animal Science

    (1970)
  • J. Diouf

    How to feed the world in 2050

  • L.R. Donaldson

    Selective breeding of salmonid fishes

  • L.R. Donaldson et al.

    Selective breeding of Chinook salmon

    Transactions of the American Fisheries Society

    (1961)
  • C.M. Duarte et al.

    Will the oceans help feed humanity?

    BioScience

    (2009)
  • R.A. Dunham

    Comparison of six generations of selection, interspecific hybridization, intraspecific crossbreeding and gene transfer for growth improvement in Ictalurus catfish

  • A.E. Eknath et al.

    Approaches to national fish breeding programs: pointers from tilapia pilot study

  • G.C. Embody et al.

    The advantage of rearing brook trout fingerlings from selected breeders

    Transactions of the American Fisheries Society

    (1925)
  • FAO

    Aquaculture production statistics, 1984–1993

  • Cited by (0)

    View full text