important since it is well known that aquaculture is the second most important vector
for species introductions after maritime transport. Also the attraction of wild fish to
net cages adds constraints to the ecosystem structure and function, in particular in
areas such as the Mediterranean, where wild fish are abundant around cages and
may be more available to fisheries (Chapter 3). Although the presence of wild
fishes at the farms can minimize the environmental impacts, e.g. through reducing
inputs of organic matter to the seafloor, there are risks such as transfer of diseases
to wild populations (Chapter 3). A related issue is the genetic pollution of wild
stocks through either inadvertent (as in farm escapes) or deliberate (as in stocking/
ranching) introduction of cultured species into the wild (Chapter 4). Genetic
impacts have been extensively studied for salmon in Northern Europe, where there
are problems with interbreeding, and are now under consideration for other cultured
species such as sea bream and sea bass in the Mediterranean and for other species
in the tropics (Chapter 4). Chapter 4 discusses the possible future solutions to the
genetic interactions between farmed and wild fish.
One major constrain to aquaculture growth is the availability of fish meal and
fish oil for production of carnivore fish (Chapters 6 and 10). There is currently a
major research effort in optimizing feed through substituting fish meal and oil with
vegetable flour and oil. As there is substantial scientific evidence of human health
benefits from consumption of marine products, primarily due to the omega-3 fatty
acids, the aims of the current research is to maintain the composition of the cultured
fish product while reducing dependence on fishery-derived feedstocks (Chapter 6).
There are also other future options for solving the bottle neck of feed availability,
which involve not only breakthroughs in feed technology but also changing the way
humanity interacts with the oceans (Chapter 10). Such breakthroughs could be
through use of marine plants for feed or moving production from carnivore to herbivore species.
Aquaculture is expected to develop along two main lines, either in net cages at
sea or on land-based facilities (Chapter 10). To keep up with the production needs
the size of the farms will expand and net cage farms will move from coastal sites
to open-ocean locations. Land-based farms have the advantage of reuse of the water
and treatment facilities, but are at the present constrained by high energy costs.
In addition to technological constrains there are several other bottlenecks, which
are less predictable. These are related to attitudinal issues (Chapters 8 and 10) and
to the economic development of the industry (Chapter 9). Aquaculture production
has for instance become of active interest to a number of non-governmental organizations (NGOs) around the world, which is discussed in Chapter 7. NGO concerns
about aquaculture are not solely in its growth or where the product is consumed.
Rather, their interest is in the on-the-ground environmental or social impacts that
threaten or undermine the NGO’s ability to deliver on their overall missions of
conservation or social welfare. Public and consumer attitudes and legislation, related
to, e.g., ethics, environment and health can play important roles, such as observed
with the threatened bird flu pandemic, where suddenly almost every consumer
stopped eating chicken. This did affect the sales of salmon from aquaculture
positively, whereas the news on high dioxin levels in cultured salmon resulted in a
Foreword
vii
for species introductions after maritime transport. Also the attraction of wild fish to
net cages adds constraints to the ecosystem structure and function, in particular in
areas such as the Mediterranean, where wild fish are abundant around cages and
may be more available to fisheries (Chapter 3). Although the presence of wild
fishes at the farms can minimize the environmental impacts, e.g. through reducing
inputs of organic matter to the seafloor, there are risks such as transfer of diseases
to wild populations (Chapter 3). A related issue is the genetic pollution of wild
stocks through either inadvertent (as in farm escapes) or deliberate (as in stocking/
ranching) introduction of cultured species into the wild (Chapter 4). Genetic
impacts have been extensively studied for salmon in Northern Europe, where there
are problems with interbreeding, and are now under consideration for other cultured
species such as sea bream and sea bass in the Mediterranean and for other species
in the tropics (Chapter 4). Chapter 4 discusses the possible future solutions to the
genetic interactions between farmed and wild fish.
One major constrain to aquaculture growth is the availability of fish meal and
fish oil for production of carnivore fish (Chapters 6 and 10). There is currently a
major research effort in optimizing feed through substituting fish meal and oil with
vegetable flour and oil. As there is substantial scientific evidence of human health
benefits from consumption of marine products, primarily due to the omega-3 fatty
acids, the aims of the current research is to maintain the composition of the cultured
fish product while reducing dependence on fishery-derived feedstocks (Chapter 6).
There are also other future options for solving the bottle neck of feed availability,
which involve not only breakthroughs in feed technology but also changing the way
humanity interacts with the oceans (Chapter 10). Such breakthroughs could be
through use of marine plants for feed or moving production from carnivore to herbivore species.
Aquaculture is expected to develop along two main lines, either in net cages at
sea or on land-based facilities (Chapter 10). To keep up with the production needs
the size of the farms will expand and net cage farms will move from coastal sites
to open-ocean locations. Land-based farms have the advantage of reuse of the water
and treatment facilities, but are at the present constrained by high energy costs.
In addition to technological constrains there are several other bottlenecks, which
are less predictable. These are related to attitudinal issues (Chapters 8 and 10) and
to the economic development of the industry (Chapter 9). Aquaculture production
has for instance become of active interest to a number of non-governmental organizations (NGOs) around the world, which is discussed in Chapter 7. NGO concerns
about aquaculture are not solely in its growth or where the product is consumed.
Rather, their interest is in the on-the-ground environmental or social impacts that
threaten or undermine the NGO’s ability to deliver on their overall missions of
conservation or social welfare. Public and consumer attitudes and legislation, related
to, e.g., ethics, environment and health can play important roles, such as observed
with the threatened bird flu pandemic, where suddenly almost every consumer
stopped eating chicken. This did affect the sales of salmon from aquaculture
positively, whereas the news on high dioxin levels in cultured salmon resulted in a
Foreword
vii