If you are debating the best way to get your fish omega threes and sixes the articles below would provide arguments for fish oil or wild fish however humble, and thats without looking at other issues.
I must admit the figures made my draw drop.
The conversion rate from wild fish as food to farmed fish is apparently about 4 or 5 to 1.
A high price to fill our shelves with particular fish types?
I am not against farming fish to preserve wild stocks but where is the environmental "value" balance.
RB
Antarctic Krill: a case study on the ecosystem implications of fishing
http://72.14.221.104/search?q=cache:...ient=firefox-a
ABSTRACT
The fish farming industry already uses up
around 75% of the world’s fish oil and
around 40% of the world’s fish meal. By
2010, these figures might go up to 90% and
56% respectively, according to predictions
by the International Fish Meal and Fish Oil
Manufacturers Association (IFOMA). FAO
has indicated that by 2010, farmed salmon and trout alone could consume 620,000 tonnes
of fish oil (Staniford 2002). With demand exceeding supply and rising prices, fish oil has
been labelled “the new blue gold” (Staniford 2001).
http://72.14.221.104/search?q=cache:...ient=firefox-a
ABSTRACT
"Number 8
Winter 2001
Effects of Aquaculture on World Fish Supplies
SUMMARY
Global production of farmed fish, shrimp, clams, and oysters more than doubled in weight and value during the
1990s while landings of wild-caught fish remained level. Many people look to this growth in aquaculture to relieve
pressure on ocean fish stocks, most of which are now fished at or beyond capacity, and to allow wild populations to
recover. Production of farmed fish and shellfish does increase world fish supplies. Yet by using increasing amounts of wild-
caught fish to feed farmed shrimp and salmon, and even to fortify the feed of herbivorous fish such as carp, some sectors
of the aquaculture industry are actually increasing the pressure on ocean fish populations.
The available scientific evidence indicates that some types of aquaculture are on a destructive path that poses a
threat not only to wild fish stocks but also to the industry’s own long-term potential. One of the most disturbing trends is
the rapid expansion and intensification of shrimp and salmon farming and culture of other high-value carnivorous marine
fish such as cod, seabass, and tuna. Production of a single kilogram of these species typically uses two to five kilograms
of wild-caught fish processed into fish meal and fish oil for feed.
Besides this direct impact on wild fish stocks, some aquaculture as currently practiced degrades the marine
environment and diminishes the ecological life support services it provides to fish, marine mammals, and seabirds, as well
as humans. These impacts include
• Destruction of hundreds of thousands of hectares of mangrove forests and coastal wetlands for construction
of aquaculture facilities
• Use of wild-caught rather than hatchery-reared finfish or shellfish fry to stock captive operations, a practice
that often leads to a high rate of discarded bycatch of other species
• Heavy fishing pressure on small ocean fish such as anchovies for use as fish meal, which can deplete food for
wild fish such as cod, as well as seals and seabirds
• Transport of fish diseases into new waters and escapes of non-native fish that may hybridize or compete with
native wild fish
As aquaculture production continues to expand and intensify, both its reliance and its impact on ocean fisheries are
likely to increase. The balance between farmed and wild-caught fish, as well as the total supply of fish available for human
consumption, will depend on future trends in aquaculture practices. If the goal of aquaculture is to produce more fish for
consumers than can be produced naturally, then it will become increasingly counterproductive to farm carnivores that must
be fed large amounts of wild-caught fish that form the foundation of the ocean food chain. Indeed, non-carnivorous
species such as marine mollusks and carps account for most of the current net gain in world fish supplies from aquaculture.
Without clear recognition of its dependence on natural ecosystems, the aquaculture industry is unlikely to develop
to its full potential or continue to supplement ocean fisheries. We recommend the adoption of four priority goals for
aquaculture:
• Encourage farming of species lower on the food web – that is, fish with herbivorous or omnivorous diets or
filter feeders such as oysters
• Improve feed management and efficiency in industrial aquaculture systems and develop substitutes for fish-
derived feed ingredients
• Develop integrated fish farming systems that use multiple species to reduce costs and wastes while increasing
productivity
• Promote environmentally sound aquaculture practices and resource management
Governments have a key role to play in developing regulations to protect coastal ecosystems and in reexamining
subsidies to unsustainable marine fisheries. Development agencies are strategically placed to help in developing and
implementing sustainable production practices and in financing otherwise economically and socially unattainable reforms in
developing countries. If public and private interests act jointly to reduce the environmental costs generated by fish farm-
ing, present unsustainable trends can be reversed and aquaculture can make an increasingly positive contribution to global
fish supplies..............."
Cover (clockwise from top): shrimp ponds in Honduras (courtesy CODDEFFAGOLF); basket of milkfish (J. Primavera); harvesting catfish in
Mississippi (K. Hammond, courtesy USDA).