Introduction
1
Abstract
Global production of Atlantic salmon and rainbow trout continues to increase, however,
despite advances in prophylaxis and vaccines, disease outbreaks are one of the major
limiting factors for the production of farmed fish worldwide. Infectious agents can increase
rapidly in susceptible stocks, especially where the general health status of the population is
poor. Therefore, the maintenance of health and the accurate diagnosis of infection are of
major importance. This book (A Colour Atlas of Salmonid Diseases) represents our current
knowledge of infectious and non-infectious diseases affecting salmonids from the view of a
diagnostic pathologist. The reader can familiarise themselves with the wide range of
conditions that we consider as ‘abnormal’ thus providing an invaluable guide to those
involved in diagnosing fish diseases. Curiosity and an open mind combined with broad
knowledge and experience remain important for the fish pathologist.
Keywords
Aquaculture Infectious disease Salmon Trout Profitability
Aquaculture has been practiced for many thousands of years
and history provides numerous examples where farming has
emerged to supplement traditional net or line fishing from
the sea, for example ancient fish farming in China. World
production of fish has not kept pace with human population
growth and today the decline or stagnation of capture
fisheries has been compensated by the rapid increase of
aquaculture production throughout the world. Species such
as carp were farmed in Roman and medieval times and
remain part of European culture and heritage, now with sea
bream and sea bass in the southern European regions.
Salmonid faming largely occurs within latitudes 40–70
in the northern hemisphere and 40–50
in the southern hemisphere. This covers Norway, Scotland, Ireland, the Faroe
Islands, Canada, and the North Eastern seaboard of the USA
in the north and Chile, Australia (Tasmania) in the south.
Minor production also occurs in France and Spain and in
New Zealand, Peru and Argentina. By the twenty-first century
farmed Atlantic salmon, rainbow trout and to a lesser extent,
Arctic char and brown trout, experienced a tremendous growth
in cold water aquaculture and was expected to continue to
increase by ~15 %, reaching a global production of ~1.8 million
tonnes by 2012. For many years Norway has led the world in
Atlantic salmon and rainbow trout production with just over a
million tonnes in 2011 with a projection of an additional 10 %
increase. In Scotland, 2011 marked the salmon sectors 40th
anniversary of its first commercial farm, currently producing
~154,000 tones and projecting a growth of 4 % per annum over
the subsequent 10 years, and widening their horizons to
include a 50 % increase in sea water reared rainbow trout.
In the southern hemisphere and since the emergence of Chile
as a strong salmon producer back in the 1980s, the region
has contributed to the global salmon market with peaks in
production similar to those of Norway.
The commercial rearing of salmon starts in fresh water with
hatcheries and juvenile growing units and subsequently fish
are transferred to sea water as they become ‘smolts’. Growers
are held in net pens (cages) or in land based tanks. Rainbow
trout typically remain in fresh water throughout their life,
although increasingly, production in sea water cages are
being utilised. Fish reach the market size around 15–18 months
later. The major species from the family are shown in Fig. 1.1
D.W. Bruno et al., A Colour Atlas of Salmonid Diseases,
DOI 10.1007/978-94-007-2010-7_1, # Springer Science+Business Media B.V. 2013
1
1
Abstract
Global production of Atlantic salmon and rainbow trout continues to increase, however,
despite advances in prophylaxis and vaccines, disease outbreaks are one of the major
limiting factors for the production of farmed fish worldwide. Infectious agents can increase
rapidly in susceptible stocks, especially where the general health status of the population is
poor. Therefore, the maintenance of health and the accurate diagnosis of infection are of
major importance. This book (A Colour Atlas of Salmonid Diseases) represents our current
knowledge of infectious and non-infectious diseases affecting salmonids from the view of a
diagnostic pathologist. The reader can familiarise themselves with the wide range of
conditions that we consider as ‘abnormal’ thus providing an invaluable guide to those
involved in diagnosing fish diseases. Curiosity and an open mind combined with broad
knowledge and experience remain important for the fish pathologist.
Keywords
Aquaculture Infectious disease Salmon Trout Profitability
Aquaculture has been practiced for many thousands of years
and history provides numerous examples where farming has
emerged to supplement traditional net or line fishing from
the sea, for example ancient fish farming in China. World
production of fish has not kept pace with human population
growth and today the decline or stagnation of capture
fisheries has been compensated by the rapid increase of
aquaculture production throughout the world. Species such
as carp were farmed in Roman and medieval times and
remain part of European culture and heritage, now with sea
bream and sea bass in the southern European regions.
Salmonid faming largely occurs within latitudes 40–70
in the northern hemisphere and 40–50
in the southern hemisphere. This covers Norway, Scotland, Ireland, the Faroe
Islands, Canada, and the North Eastern seaboard of the USA
in the north and Chile, Australia (Tasmania) in the south.
Minor production also occurs in France and Spain and in
New Zealand, Peru and Argentina. By the twenty-first century
farmed Atlantic salmon, rainbow trout and to a lesser extent,
Arctic char and brown trout, experienced a tremendous growth
in cold water aquaculture and was expected to continue to
increase by ~15 %, reaching a global production of ~1.8 million
tonnes by 2012. For many years Norway has led the world in
Atlantic salmon and rainbow trout production with just over a
million tonnes in 2011 with a projection of an additional 10 %
increase. In Scotland, 2011 marked the salmon sectors 40th
anniversary of its first commercial farm, currently producing
~154,000 tones and projecting a growth of 4 % per annum over
the subsequent 10 years, and widening their horizons to
include a 50 % increase in sea water reared rainbow trout.
In the southern hemisphere and since the emergence of Chile
as a strong salmon producer back in the 1980s, the region
has contributed to the global salmon market with peaks in
production similar to those of Norway.
The commercial rearing of salmon starts in fresh water with
hatcheries and juvenile growing units and subsequently fish
are transferred to sea water as they become ‘smolts’. Growers
are held in net pens (cages) or in land based tanks. Rainbow
trout typically remain in fresh water throughout their life,
although increasingly, production in sea water cages are
being utilised. Fish reach the market size around 15–18 months
later. The major species from the family are shown in Fig. 1.1
D.W. Bruno et al., A Colour Atlas of Salmonid Diseases,
DOI 10.1007/978-94-007-2010-7_1, # Springer Science+Business Media B.V. 2013
1