The greater risk of the farming of salmon, shrimp and other carnivorous species is that they tend to consume more of the ocean’s resources than they add to the global stock. Carnivorous farmed fish consume processed feed made from wild catches of herring, mackerel, sardine and other pelagic ocean varieties. It is estimated that as much as two to four pounds of wild fish are required for every pound of farmed carnivorous fish raised on processed meal.

Hence, approximately 80% of world wild-caught pelagic fish are reduced to fishmeal and fish oil. Further, almost half of world annual production of fishmeal and 80% of fish oil is currently being used for aquaculture feed. (Interestingly, I believe meat (cows, pigs, chicken feed etc) and dairy production use most of the rest.) Yet salmon represent less than 7% by weight of all aquaculture production, but use 41% of the fish oil consumed by the industry. It is hard to conclude that these figures could possibly resemble a sustainable formula. With salmon farming helping to create this strong demand for fishmeal and fish oil the pressure on the small pelagics will affect the entire food fish chain of major ecosystems (leaving less fish for wild carnivorous species to eat) and the poor, because price increases will take these small pelagic staples out of their reach.

Thus, its is not just concerns about having higher levels of mercury, disease, PBDEs and flame retardants in farmed salmon that we should be examining when we buy farmed salmon but its global impact on our already dwindling ocean resources (thanks as well to other factors like, over-fishing, pollution, global warming and other carnivorous farmed fish production.)

This is a well-documented issue but not well known to the general public and an issue I hope GreenDaily and others will follow more closely given the gravity of its potential impact. Global ocean resource depletion may be the next crisis to compete with global warming and the growing land based food/fuel crisis in its potential negative impact on the environment.

Please note that the farming of herbivorous species do not pose the same environmental impacts because they typically do not require wild fish to be caught and processed for fish feed or fish oil. Like human vegetarians, vegetarian fish tend to have less negative impacts than meat eaters. One may see a pattern developing here.

"Global production of farmed fish and shellfish has more than doubled in the past 15 years. Many people believe that such growth relieves pressure on ocean fisheries, but the opposite is true for some types of aquaculture. Farming carnivorous species requires large inputs of wild fish for feed. Some aquaculture systems also reduce wild fish supplies through habitat modification, wild seedstock collection and other ecological impacts."
Rosmond Naylor, Rebecca J. Goldburg, Jurgenne H. Primavera, Nils Kautsky, Malcolm C. M. Beveridge, Jason Clay, Carl Folke, Jane Libchenco, Harold Mooney, and Max Troell, Effect of aquaculture on world fish supplies, Nature, Vol. 405 (29 June 2000). http://fse.stanford.edu/publications/effects_of_aquaculture_on_world_fish_supplies/


See also:
Christopher L. Delgado, Nikolas Wada, Mark W. Rosegrant, Siet Meijer, and Mahfuzuddin Ahmed, (2003) Fish to 2020: Supply and Demand in Changing Global Markets, International Food Policy Research Institute and WorldFish Center

Albert J. Tacon, Aquaculture production trends analysis, in: Review of the State of World Aquaculture. FAO Fisheries Circular No.886, Rev.2. Rome, FAO. 2003

The World Bank - Agriculture and Rural Development Department, Saving Fish and Fishers - Toward Sustainable and Equitable Governance of the Global Fishing Sector, Report No. 29090-GLB (May 2004)

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Many of us who grew up in a fishing-seafood market community...know first hand how important marine ecosystem are.

Fishes, shrimps, crabs, and other marine species are a vital part of the world's food/market supply-demand.

I also agree, there are passionate concerns with recent environment shifts marine-ocean patterns too.

Interesting article on "a matter of survival," Thanks for posting.

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