by Craig Weatherby
The dubious sustainability of farmed salmon drew a great deal of attention at the Seafood Summit presented in Paris by the Seafood Choices Alliance.
The Alliance helps the seafood industry move toward increasing sustainabilty, with guidance from the marine scientists at SeaWeb.
Usage of fishmeal in carnivorous fish feeds was the chief focus of a first-day session titled, “Will salmon feeds become independent from fishmeal?”
The average propportion of fishmeal used in fish-farm feed has dropped from about two-thirds to about one-quarter... but that's as low as it can go, since chow with less than 25 percent fishmeal causes growth and health deficiencies.
And grain-heavy feeds produce unhealthful but generally overlooked negative impacts that on the fat profiles of fish. For more on that, see “Farmed Fish Possess Unhealthful Fat Profiles” and “Farmed Salmon's Diet Yields Unhealthful Cardiovascular Effects.”
On that score, grain-heavy fish feed is a bad idea, even though it cuts the cost of farmed fish and reduces the numbers of critical forage fish ground up to feed farmed salmon, catfish, shrimp, barramundi, tilapia and other species.
The aquaculture industry’s use of fishmeal was critiqued by several members of the audience, including representatives of the Pure Salmon Campaign, who debuted a 23-minute film titled “Farmed Salmon Exposed: The Global Reach of the Norwegian Salmon Farming Industry.”
Fish fed to fish… an unsustainable practice
Much of the fishmeal fed to farmed fish consists of critical forage species like sardines, herring, and menhaden, upon which larger wild fish rely for sustenance. Of these species, menhaden is under the most serious threat by far, with overharvesting of these fish worsening the decline of the Chesapeake Bay.
Dr. Andrew Jackson of the International Fishmeal and Fish Organization (IFFO) presented evidence that as the aquaculture industry has grown, so has its dependence on fishmeal.
In 1980, fish farms accounted for 10 percent of global fishmeal consumption; by 2008 that figure had grown to 58.8 percent.
(Pigs on factory farms accounted for about 31 percent of global fishmeal consumption in 2008, down from 50 percent in 1960.)
Among farmed seafood, salmon and shrimp account for more than half of all fishmeal consumption, at 29 and 28 percent of the global total respectively.
Dr. Jackson also added that species largely considered herbivorous—catfish and tilapia, for example—also use fishmeal during their juvenile stages when those fish are carnivorous.
Peter Tyedmers, Ph.D., of Dalhousie University in Nova Scotia, Canada, and Astrid Scholz, Ph.D., of Ecotrust shared the results of their life-cycle assessment (LCA) studies of salmon-production systems during the session, “Building Better Salmon: Improving the life cycle of seafood supply chains from fish to fork.”
An LCA is a detailed measurement of the carbon footprint or greenhouse-gas emissions from every part of a particular production system, from farm or boat, to fork.
Tyedmers and Scholz evaluated several wild-capture and aquaculture operations and determined that frozen-at-sea (FAS) wild salmon from Alaska was the gold standard.
(For more on their landmark life-cycle assessment, see “Frozen Wild Fish Found Greener than Fresh or Farmed.”)
“You cannot outperform, from a climate and environmental standpoint, wild Alaskan salmon,” said Dr. Scholz.
And as Dr. Tyedmers said, “It’s all about the feed... there are only about 12 people in the world who decide what goes into salmon feed, and they could be responsible for substantial changes.”
- Wright J. Seafood Summit: All eyes on salmon. February 2, 2010. Accessed at http://seafoodsource.com/ newsarticledetail.aspx?id=4294988961