Trouble with aquaculture


in Economics, Science, The environment

Recently, Manitoba banned new hog farms in a wide swathe of the province due to environmental concerns. Now, British Columbia has suspended the issuing of new licenses for salmon farms. The ecological impact of these facilities has been mentioned here before.

Generally, the idea that open-pen aquaculture makes ecological sense for carnivorous species like salmon is fallacious. All it does is displace pressure from fishing activity from wild salmon themselves to the kind of fish they eat. Inevitably, an unconstrained fishery will destroy those stocks as well. Meanwhile, the salmon farms leach lice, excrement, and antibiotics into the waters around them.

{ 11 comments… read them below or add one }

tristan April 3, 2008 at 7:47 pm


Litty April 3, 2008 at 10:14 pm

Is this likely to have a big effect on salmon prices?

Milan April 3, 2008 at 10:40 pm

I have no idea, really.

If demand rises a lot and existing salmon farms cannot handle it, it is possible prices will rise significantly.

Neal April 4, 2008 at 3:21 pm

Too little too late. I doubt salmon stocks in BC will ever recover to even what they were as little as 20 years ago.

. April 7, 2008 at 3:15 pm

Many fishers support West Coast fishing ban (04/07/2008)

The unprecedented collapse of one of the West Coast’s biggest salmon runs has prompted even those who depend on fishing for a living to call for a complete shutdown of salmon fishing off the coasts of California and Oregon.

“There’s likely no fish, so what are you going to be fishing for?” asked Duncan MacLean, a fisher from Half Moon Bay. “I have no problem sitting out to rebuild this resource if that’s what’s necessary.”

The Pacific Fishery Management Council meets in Seattle this week and is expected to make a final decision Thursday, when it will likely vote to impose the most severe restrictions ever on West Coast salmon fishing to protect California’s dwindling chinook stocks.

Only about 90,000 adult chinook returned to the Central Valley last fall — the second-lowest number on record and well below the number needed to maintain a healthy fishery. That number is projected to fall to a record low of 58,000 this year. By contrast, 775,000 adults were counted in the Sacramento River and its tributaries as recently as 2002.

Biologists and others are trying to figure out what caused the salmon collapse so they can make sure California’s chinook populations rebound.

There are many potential factors, because wild salmon are born in streams and rivers, migrate to the ocean when they are juveniles and spend two to four years there before returning to spawn in the areas where they were born. In between they have to navigate the often treacherous waters of the Sacramento-San Joaquin Delta and San Francisco Bay.

The council has asked state and federal scientists to research 46 possible causes, including water diversions, habitat destruction, dam operations, agricultural pollution, marine predators and ocean conditions (Land Letter, March 20).

Many fishers and environmentalists believe the main problem lies in the Sacramento-San Joaquin Delta, where they say too much water is being diverted to farms and water districts in the San Joaquin Valley and Southern California.

They want the state and federal government to limit pumping from the delta, which disorients migrating salmon and kills young fish that get sucked into the powerful pumps. They are also calling for a reduction in agricultural runoff and the restoration of salmon habitat in the rivers.

But state water officials believe the ocean is the chief culprit. The water pumps continue to meet stringent operating standards, and while more water has been diverted in recent years, there’s also been more water available to export, said Jerry Johns, deputy director of the California Department of Water Resources.

“Ocean conditions are the most likely cause here,” Johns said. “The requirements that we have to abide by to protect these fish haven’t changed in the last several years”

. April 8, 2008 at 3:22 pm

A Problem of Scale

Chilean salmon-farming industry in a sad state

A virus called infectious salmon anemia is sweeping through Chile’s fisheries, bringing attention to the condition of the country’s third-largest export industry. On expansive salmon farms, fish are bred in crowded underwater pens. Fish poop and food pellets contaminate the water. As many as 1 million nonnative salmon escape each year, gobbling native species and traveling as far as Argentina. The fish are treated liberally with antibiotics, some of which are prohibited for use on animals in the U.S. — but 29 percent of Chilean exports end up in American grocery stores. Salmon farming was welcomed as an economy-booster two decades ago, but in the wake of the virus, some in the industry are leaving in search of more pristine waters. Says one local fisher, who claims salmon farming has affected the quality of wild fish as well: “They bring illnesses and then leave us with the problems.”

Milan April 12, 2008 at 8:32 pm

Fishery managers voted to cancel the chinook salmon fishing season off the coast of California and most of Oregon in light of the fish population’s rapid collapse. The commercial fishery is worth an estimated $30 million.

Milan April 12, 2008 at 8:32 pm

This week in ocean news
By Andrew Sharpless

Fishery managers voted to cancel the chinook salmon fishing season off the coast of California and most of Oregon in light of the fish population’s rapid collapse. The commercial fishery is worth an estimated $30 million …

… many fishermen considered supporting the ban on West Coast salmon fishing in light of this year’s record low catch. “There’s likely no fish, so what are you going to be fishing for?” said one.

… while some other fishermen went ahead with a pre-season barbeque, although it was less well attended than in past years …

… the federal government and four Northwest Indian tribes reached a settlement that would commit the U.S. to spending $900 million to save salmon in the next decade. Reaction to the plan, which keeps dams in place, was mixed. “It’s a sad day for me,” said the governor of Oregon …

… a biologist considered a plan to save British Columbia salmon by gathering up the juveniles and moving them past fish farms where the wild salmon often are killed or infected by sea lice. She could face a $100,000 fine for doing so …

… a hundred years ago, the Maine salmon season started with this proclamation in the Bangor Daily Commercial: “There will be fishermen on the pools as soon as daylight shines, for a great rivalry exists among the salmon fishermen over the taking of the first salmon … there is a big pecuniary incentive, for the first salmon usually sells for about $1.25 a pound” …

… some estimated the price of wild salmon could hit $40 a pound this year …

… scientists who were conducting genetic tests of wild salmon faced the possibility of having no salmon to test …

… and the champion Irish racehorse Beef or Salmon was set to retire.

. July 17, 2008 at 1:56 pm

Give a fish a bad name, June 28th


SIR – Your article on how to rescue the reputation of Chilean salmon discusses contaminants, but there is a larger issue: the invasion of aquaculture fish that can play havoc with native biodiversity.

. August 11, 2012 at 11:15 pm

B.C. fish farms to kill 300,000 salmon

CTV British Columbia
Published Thursday, Aug. 9, 2012 10:32AM PDT

Two B.C. fish farms have received orders from the Canadian Food Inspection Agency to kill more than 300,000 Atlantic salmon after the IHN virus was confirmed at both sites.
The BC Salmon Farmers Association said in a release the virus has now been confirmed at Mainstream Canada’s Millar Channel farm north of Tofino and Grieg Seafood’s Culloden Point farm in Jervis Inlet on the Sunshine Coast.

“The first priority for these companies is to work with CFIA to ensure that any depopulation is done quickly and safely,” said Mary Ellen Walling, Executive Director of the BCSFA.
Both companies tested positive for IHN last week during routine tests and followup tests confirmed the findings.
In June, Mainstream Canada culled more than 560,000 fish at one of its Dixon Bay farm, north of Tofino.

. September 16, 2017 at 5:07 pm

Dr Wang knew from previous reports that fish farmers who had not used antibiotics for years, or had never used them at all, still had sediment in their marine farms carrying bacteria with many of the genes associated with drug resistance. The genes had to be getting into the bacteria somehow; one possible pathway was through antibiotic-resistance genes in fish food mingling in various ways with bacteria in the sediment.
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Working with a team of colleagues, Dr Wang set up an experiment to find out if that was the case. As they report in Environmental Science and Technology, the researchers obtained five commonly used fishmeal products and subjected each one to a detailed genetic analysis. This revealed the presence of 132 drug-resistance genes, suggesting that heavy antibiotic use on the fish products which are themselves ground up into fishmeal formulations, was behind the transfer of genes.

The results were clear. Although the control microcosms started with some resistance genes present (as there is bound to be in nature) the number did not increase. In contrast, the number of resistance genes present in the microcosms exposed to the Peruvian fishmeal increased tenfold.

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