BLUE REVOLUTION REVISITED continued from Homepage
The same level of enthusiasm and optimism for industrial aquaculture heard today was expressed decades ago for industrial agriculture. Beginning in the 1940s, small-scale mixed farming gave way to massive monoculture operations run by vertically integrated corporations, all in aid of feeding a growing and hungry world population. The transition became known as the ‘Green Revolution’ and it harnessed new and emerging science and technology to develop high-yielding cereal grains and genetically modified crops, produce synthetic fertilizers, build a massive irrigation infrastructure and manufacture an arsenal of pesticides and herbicides.
Whether the Green Revolution delivered on its promise to feed the hungry of the world is still being debated. Few would disagree, however, that there has been a decline in agricultural biodiversity where only a few varieties of high-yielding crops are now grown world-wide. Increased use of synthetic fertilizers has polluted coastal and freshwater ecosystems. Farmlands have been turned into deserts and insects and diseases have developed resistance to pesticides and antibiotics.
Similar issues now plague industrial aquaculture.
Kona Blue Water Farms in Hawaii. A proposed facility in Hawaii would be in a 247 acre site and raise 12 million pounds of yellowfin tuna per year in 12 of these untethered cages. Source and Photo FWW
Dirty bottoms
Clyde Fisher has fished Port Mouton Bay in southwest Nova Scotia for 45 years, the last 20 of those 45 years he fished lobster. He knows the Bay and lobsters like the back of his hand.
Earlier this year, Clyde and several other residents of Port Mouton hosted a ‘kitchen talk’ for researchers attending a conference on community involvement in coastal research and management. Asked if it was true what some representatives of the salmon farming industry say about lobster fishing being good around salmon farms, Clyde responded by saying, “It’s good lobstering the first year but they never ever tell you the rest of it.” According to Clyde, three years into a farm’s operation the lobsters move away because the bottom has become “dirty,” and by that he means “when everything is dead.”
Clyde should know because a salmon farm had operated in his fishing grounds continuously for about 15 years. In 2009, the farm ceased operating. Years of fecal waste and uneaten food raining down and accumulating on the bottom had caused the sediments to become too toxic to grow fish. It is now the site of a community-university research project studying beyond-the-farm and post-farm impacts.
New Brunswick fishermen who have had a much longer history with salmon farming make similar observations as Clyde. A 2011 study led by University of New Brunswick (UNB) anthropologist Melanie Wiber documented fishermen’s observations about environmental changes in their fishing grounds, particularly in areas where aquaculture had been introduced. In the report, New Brunswick fishermen confirm that in the first year of stocking a salmon cage lobsters move in (attracted by the increased feed on a relatively clean bottom), but by the third year they are gone. After a farm has been in operation for several years, the sea bottom around fish farms is described as “mildewed or moldy” and largely a “dead zone”.
The changes observed by fishermen match those made in numerous scientific studies. An initial increase in food in the form of uneaten feed and feces attracts numerous species and increases the biological diversity around a salmon farm. As the waste load from the farm increases, the chemistry of the sea bottom begins to shift from an oxygen-rich to an oxygen-poor environment. Sulphide levels begin to rise. The color and quality of the sediment changes.
Extensive mats of white bacteria develop and species diversity begins to drop off. The extent of the changes depends on several factors including the stocking density of the farm and the natural ability of the environment to deal with the increased waste load. Areas where bottom currents are weak become dead more quickly.
Changes in lobster behavior and the sea bottom are not the only impacts from salmon farms observed by fishermen.
Oceans in trouble
By volume, dissolved nitrogen and uneaten feed and feces are the major wastes released from open net-pen salmon farms. Dissolved nitrogen or nutrient pollution has been called the “most damaging class of pollutants in the marine environment” by the United Nations Group of Experts on Marine Pollution. Nutrient pollution triggers a response in the marine ecosystem that, if unchecked, results in the creation of dead zones. The number of dead zones in the world coastal waters has jumped from 50 in 1999 to 400 in 2008. A 2007 update on the status of estuaries in the US by the National Ocean and Atmospheric Administration (NOAA) rated symptoms of nutrient pollution in estuaries from Cape Cod to Maine as “bleak” with conditions “expected to worsen in the future.”
The most visible sign of nutrient pollution is ‘green and brown tides’ or carpets of bright green and slimy brown algae in intertidal areas. Missed by most people, but not fishermen, are the changes to the surrounding water quality, species and bottom habitat. In the 2011 UNB study of aquaculture-traditional fisheries interactions, fishermen commonly reported “sewage” odours when working near aquaculture sites. They reported declines of green and brown kelp associated with healthy sea urchins and good roe production and losses of “hard bottom”or gravel areas that are preferred by lobster, scallops and sea urchins.
A 2005 New Brunswick study provided a rare insight into the scale of waste released from salmon farms. The study by Canadian Department of Fisheries and Oceans (DFO) scientists calculated the nitrogen and carbon waste from all point and non-point sources, including the salmon farms, in the L’Etang estuary. At the peak of their production cycle, fish farms in the estuary released almost 50 times more nitrogen and carbon waste than the sewage plant servicing a community of 1,200 and more waste than a pulp mill and herring processing plant. No such study has been done in Maine.
Other pollutants released from salmon farms are pesticides used to treat sea lice, antibiotics used for disease control and antifoulants on nets and other equipment. Government and industry officials claim that, if used properly, these chemicals are safe. However, the studies done to approve these chemicals have not examined the cumulative, longer-term impacts of multiple chemical exposures on the wide-variety of other species that share the waters with farmed salmon, so-called non-target species. According to the 2011 UNB study, New Brunswick fishermen report mortalities in lobster pounds have increased dramatically after chemicals to treat sea lice have been used in their area.
Technical, regulatory fixes? Not yet
Like industrial agriculture, the salmon farming industry has enlisted the power of science and technology to make improvements in their operations. Most of their effort has been directed to improving production and efficiency. Automated feeding has reduced the number of workers needed to operate a single farm. Underwater cameras have helped to improved feed efficiency.
A genetically modified salmon that will grow faster has been developed but not approved for commercial production.
As for addressing their environmental impacts, changes to the composition of feed pellets have reduced the use of wild fish and the development of vaccines has reduced the use of antibiotics. In some jurisdictions, management practices similar to those used in intensive agriculture such as fallowing and a form of crop-rotation referred to as bay management have been introduced.
Any benefits gained from these improvements have been offset by an increase in farm sites and the number of fish produced per farm. Farms which once raised 100,000 now raise 300,000 to 700,000 fish and where there were once three or four farms, there are now 20. Fallowing and bay management have failed to stop disease and sea lice epidemics or to prevent 20 percent of salmon farms in New Brunswick from routinely requiring some kind of remediation because the sea bottom under their net pens has become so toxic that 60 percent - 70 percent of biological diversity has been lost.
Technological developments that would allow salmon farms to move further offshore into deeper waters or into closed systems have been very slow to evolve despite decades of effort. A more recent proposal to manage fish farm waste is integrated multi-trophic aquaculture (IMTA), the process of growing shellfish and seaweeds next to salmon farm to gobble up the excess nutrient and organic wastes. To date, scientific studies have failed to demonstrate IMTA’s effectiveness. At the 2007 annual meeting of the Aquaculture Association of Canada, the leading university and federal government proponents of IMTA acknowledged that “...it is not possible to report a general ‘mitigation’ or nutrient recovery value for an IMTA system” because “the bulk of the nutrient load from a fish farm is sequestered in the heavier settleable solids, not accessible to the co-cultured species presently grown at the IMTA sites.”
Regulatory agencies have failed to respond to the challenges of managing the broader environmental impacts of salmon farms for several reasons. There is too much administrative discretion in the application and enforcement of environmental laws. Environment risk assessment tools are inadequate and they are inconsistently used in the application/approval process. More significantly, the process of siting, monitoring and managing salmon farms has been done on a farm-by-farm basis and the cumulative or ecosystem impacts have been largely ignored.
Fisheries, ocean restoration undermined
Reversing the decline in wild fish stocks and improving ocean habitat will require local and international action. Citizens have responded to the challenge and have formed countless organizations and groups dedicated to protecting and restoring coastal habitats and water quality. Their efforts, however, are being undermined by the growth and expansion of open net pen fish farming.
Salmon farms operate like industrial feedlots in coastal waters. They generate large quantities of wastes and the cost of waste disposal is paid by the environment and not the industry. All the science and technology being pressed into the service of expanding industrial salmon farms has not succeeded in keeping fish or the environment healthy. It has failed to prevent the desertification of sea bottoms, eliminate the release of chemical pollutants, prevent interactions between farmed and wild salmon populations and prevent the outbreak and spread of pests and diseases.
If federal regulators are serious about their mandate to protect ocean habitat and the commercial fish stocks they support, they need to immediately begin developing plans to transition salmon feedlots from the sea to land, to closed containment farms, where as with other industries, salmon farm operators will finally have to pay for the real cost of production.
An excerpt of Clyde Fisher’s ‘kitchen talk’, recorded by Tom Sherman on June 26, 2011, is available at: http://www.youtube.com/watch?v=JeUwXbIzbzs
To download the full study on fishermen’s observations on aquaculture-traditional fisheries interactions by Melanie Wiber, Sheena Young and Liz Wilson, go to: http://www.coastalcura.ca/documents/LEKStudy_2011_000.pdf
Inka Milewski is a marine biologist and author and co-author of several publications on the impacts of salmon farms on the coastal environment. In 2002, she testified as an expert witness before the State of Maine Board of Environmental Protection on proposed regulations for aquaculture and, in 2002, before the State of Maine Board of Environmental Protection on a proposed aquaculture site in Loring Cove, Maine. She has also testified on aquaculture impacts before the Canadian House of Commons Standing Committee on Environment and Sustainable Development, the Senate Standing Committee on Fisheries and Oceans and the House of Commons Standing Committee on Fisheries and Oceans.