Fish farming generates pollution, antibiotic-resistant bacteria
More environmental groups, food safety experts and so-called economic justice organizations are launching educational campaigns so consumers know just what they’re buying into when they purchase farmed seafoods like salmon and shrimp.
Phil Lansing, a resource economist with the Institute of Agriculture and Trade Policy, compares coastal aquaculture to livestock feed lot confinement operations and believes it raises similar policy and social questions.
"Consider a huge confinement facility with thousands of hogs," Lansing said. "Now put it on a dock. It would be very inexpensive to deal with the sewage because it could just be pushed off the dock. And if you gave lots of antibiotics to the animals, as well as in their feed, that would land in the water too. That’s what happens with floating net pens, because there is no treatment of the sewage or effluent.
"You get a dead zone from the sewage underneath the pen. High concentrations of nitrogen float downstream, and antibiotic-resistant bacteria build up in shellfish in the vicinity. And while it’s not well-documented because of a lack of monitoring, you get fish diseases and deadly salmon parasites like sea lice from fish in net pens. Also, rough weather results in mass escapes of hundreds of thousands of Atlantic salmon, and that will continue as long as there are net pens."
As with other environmental groups, the institute is not against fish farming that is conducted on land in contained facilities, but they object very strenuously to the open pen operations. More studies are revealing that one of the most serious problems is that they are producing significant amounts of antibiotic resistant bacteria.
Farmed fish are routinely fed antibiotics to control disease, or in what’s called sub-therapeutic amounts as an aid to growth. When humans eat farmed fish laced with antibiotics, they can develop resistance to the drugs when they are prescribed by doctors. Many worry this is becoming a major world health issue.
Lansing also points out that farmed fish operations put tremendous pressure on wild stocks, which are captured and ground up for fish meal. It takes three to five pounds of wild fish to produce one pound of farmed salmon.
Fish farmers, on the other hand, argue that they are aware of and dealing with the environmental and health issues raised by the institute and other organizations.
A poll released last month by the British Columbia Salmon Farmers Association, for example, found that 71 percent of those surveyed throughout the region believe fish farming is an environmentally sound industry. About 80 farms operate in British Columbia today. Open pen fish farms are also expanding in Maine and Washington.
The institute and others want fish farmers to start paying for monitoring, as well as the environmental costs of their businesses. Activists find, however, that they are limited as to what they can do, because environmental standards are almost nonexistent, little baseline monitoring data has been established and there are almost no enforcement measures for fish farms that are largely in remote areas.
The groups want government agencies to strengthen and enforce existing laws and regulations related to fish farming, including water quality protection, food safety issues related to colorants and dyes, and other issues.
They are also trying to convince policy makers and industrial aquaculture companies to adopt a moratorium on further expansion until adequate environmental and social protection laws and regulations are in place.
We are what we eat
A report by the Santiago-based Terram Foundation claims that salmon farmers in Chile are using cancer-causing green malachite for treatment of parasite and fungal infections. Green malachite is a triphenylmethane dye used in Chile’s leather shoe industry and is banned for use in fish farms.
The WorldCatch News Network reports that the foundation also accuses the country’s fish farm industry of using 75 times more antibiotics than Norway does to treat diseased fish. It also estimates that the organic waste from Chile’s fish farming industry is equal to the wastewater from five million people.
The foundation is scheduled this month to present the first of three reports that provide measured data on impacts to the environment caused by fish farms.
Kodiak-based free-lance writer Laine Welch can be reached via e-mail at ([email protected]).