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Survival of Pacific Salmon Threatened by Fish Farms

Pink Salmon
Figure 1: Pink salmon (Oncorhynchus gorbuscha).
Credit: Pacific Fisheries Resource Conservation Council.

January 8, 2003: Dozens of open net-cage salmon farms occupy the sheltered waters between the islands and in the deep sea inlets that make up the Broughton Archipelago on British Columbia's lower coast. The same waters provide the region's native salmon their only means of passage between the ocean feeding grounds where they grow to adulthood and the rivers and streams where they return to spawn. There is evidence that the fish farms are sources of disease and parasites that pose a mortal threat to the survival of the wild salmon. That the threat is imminent is indicated by the following excerpt from an open letter by Alexandra Morton, research biologist and long-time resident of the Broughton Archipelago.

Date: Wed, 06 Nov 2002
To: fishnet/
From: "Alexandra Morton"
Subject: Area 12 Mainland pink disaster & lice

Dear subscribers to (BC) FishNET:

There is a critical situation mounting here in the mainland inlets of Area 12. In a meeting last week chaired by the Pacific Fisheries Resource Conservation Council (PFRCC), the Department of Fisheries and Oceans (DFO) presented on the severity of the 2002 pink salmon decline in Kingcome Inlet, Tribune Channel and Knight Inlet, collectively known as the Area 12 Mainland Inlets. The DFO stated that this decline was unprecedented in magnitude and scope. There was a 98% decline (from five million) in the number of fish returning to eight rivers geographically linked in the marine environment, but isolated in freshwater. This decline was "hugely significant" and epicentered over the Broughton Archipelago. There has been no equivalent decline since DFO began record keeping in 1953.

The DFO explored this collapse further to report that there was no evidence that the causal factors were in the freshwater or the open ocean. Dissolved oxygen concentrations, temperatures and water flows in the rivers and the closely monitored spawning channels were not such as to cause a die-off. Rivers to the north, such as the Bella Coola, had more pinks than the brood year. This trend continued into Alaska with fair to excellent returns everywhere. To the south, the Philips came in at half the brood year at last count, the Puntledge at double brood year and the Quinsam 25% down. All these runs were within the high natural variability of pink salmon (see "current events).

The good pink returns elsewhere led the DFO to report that the causal factors for the Area 12 decline did not occur in the open ocean. They reported that whatever reduced these populations to 2% of brood year must have been in the nearshore marine environment.

I studied this run of pink salmon in the nearshore marine environment as they went to sea in the spring of 2001. The pink fry were exceptionally abundant, to the point that DFO herring survey contractors noted the fact in their field journals. There were acres of fry blackening entire bays and swaths of coastline. I used techniques accepted in the scientific literature to sample 700 of these fish from throughout the Broughton Archipelago. Then, with the guidance and co-authorship of Scottish and Norwegian sea lice experts, I produced a paper on these fish, which is now under peer-review in Europe. Seventy-eight percent of the fish near salmon farms were infected with more lice than they could likely survive. The fish caught in areas where there were no salmon farms between capture site and the river had few lice or none.

To calculate the lethal load of lice, I took what is known for the much larger post-smolt Atlantic salmon, for which a load of 1.6 lice per gram of host is lethal. I did not adjust this number to take account of the smaller size (0.3 to 0.8 gram) of the pink salmon smolts, so my estimate of 78% mortality may be conservative.

I contacted the top pink salmon experts in Alaska, where the political air on salmon farms is clearer, to ask if they had ever seen lice on juvenile pink salmon. Dr. Bill Heard simply said, "no."

I repeated my observations this year, with assistance from DFO, a grad. student, and an SFU mathematician and collected fish from Prince Rupert, Bella Bella and here in the Broughton Archipelago. The story became even clearer. There were three sea lice, total, of a different species, on the 550 Prince Rupert fry/smolts sampled. In Bella Bella, there were no lice except in samples from near the salmon farms at Jackson Pass. Here in the Broughton, wild juvenile salmon were 10-times more infested near farms stocked with mature salmon and 3-times more infested near farms stocked with smolts than at locations away from farms. Eighty-six percent of salmon near farms were infested in excess of the presumed lethal level.

This scenario has played out everywhere there are salmon farms and wild salmon share the marine environment. This is nothing new. It has been observed in Ireland, in Scotland and in Norway. In addition, I am discovering that salmon farmers in B.C. have completely disregarded the protocols adopted in Europe to protect wild salmon from sea lice near salmon farms.

The question remains: what about the progeny of the last 2% of the even cycle pink salmon of the Area 12 mainland inlets? After examining over 2,000 juvenile pink and chum salmon, I anticipate that these stocks will be driven to extinction. Although I was not licensed to survey other species, I saw sockeye, coho, z, sea run cutthroat, black cod, sole and many other species covered in lice of several species around the farms. Although my observations do not prove that salmon farms were the source of lice infestation, they provide a basis, given the global occurrence of this scenario, to act on the "precautionary principle." We can expect a domino affect with the shortest life-cycle species showing decline first and other species every year thereafter... The only proven method to reverse wild salmon declines caused by sea lice associated with fish farms is to fallow all the farms.

Pacific Salmon Resource Conservation Council Confirms Threat
The threat to native salmon in the Broughton Archipleago that Alexandra Morton describes was confirmed by a November 2002 report to British Columbia's Minister of Agriculture, Food and Fisheries prepared by the Pacific Salmon Fisheries Resource Conservation Council (PFRCC) (1). As stated in a covering letter by PFRCC Chair, the Honourable John A. Fraser, the number of spawning pink salmon returning to the Broughton Archipelago decreased from 3.615 million fish in the fall of 2000 to 147 thousand fish in the fall of 2002, a decline of more than 95%. The letter further stated that the decline in number of spawning fish was essentially confined to the Broughton Archipelago, indicating that it was the result of conditions specific to the Archipelago. In particular, the letter states, "There is evidence that the Broughton pink juveniles were infested with sea lice, a condition essentially unreported for juvenile pink salmon in the natural environment elsewhere." On the source of this infestation and its consequences, the PFRCC Chair referred to "European research [which] indicates that sea lice abundance can be associated with salmon farming," and stated that "the Council believes that sea lice were associated with the decline observed in the Broughton Archipelago." The recommendation of the Council was that fish farms throughout the Broughton Archipelago be fallowed to break the lice life cycle.

Ecological and Economic Consequences of Pink Salmon Extinction
Extinction of the native salmon species would have large ecological and economic repercussions. These impacts were concisely explained by Alexandra Morton in a recent radio interview, from which the following comments are taken (2).

The pink salmon are nutrient carriers. They take the photosynthesis of the open ocean up rivers and streams as far as the glacial fields of British Columbia. Their phosphorus has been found in the meat of mountain goats. The pink salmon, by virtue of their abundance, shelter the coho, the steelhead and the Chinook from predation by bears. The pink salmon feed the bears, the wolves, the eagles and local human communities.

Nutrients from the feces of salmon-feeding predators and from the decaying carcasses of fish that have spawned feed the plant community. The growth rings of trees beside the rivers can be measured by the size of the pink salmon runs. The eggs of insects that are laid on the carcasses of pink salmon hatch in the spring into small bugs that feed the coho, the steelhead and the Chinook, all of which stay in the river for a year after they have hatched. The pink salmon harvest none of this nutrient source, but head for the sea the moment they hatch and emerge from the gravel of the spawning beds.

If we lose the pink salmon, we will lose the coho, the steelhead and the Chinook. We will lose the grizzly bears, and the killer whales will be impacted. We will lose the tourism industry and the fishing industry. The fertility of the forest will be diminished. Instead we will have only salmon farming." (1)

Who Will Act to Protect British Columbia's Native Salmon?
On November 19, 2002, Canada's Department of Fisheries and Oceans (DFO) (now Fisheries and Oceans Canada, FOC) issued a press release, which in total contradiction of the conclusions of the PFRCC report, rated sea lice infestation as a fourth and merely possible factor in the collapse in the number of pink salmon returning to the Broughton Archipelago (3). Regrettably, this inconsistency is quite consistent with DFO's past administrative inability to formulate policy logically based on its own, expensive scientific expertise (4). Pulling no punches, Alexandra Morton challenges the DFO's interpretation of the evidence of its own scientists in an open letter from which the following is an excerpt.

Date: Wed, 20 Nov 2002 07:42:01 -0800
From: "Alexandra Morton"
Subject: witness11/19

Dear colleagues, friends, family and fish farmers:

The power of the aquaculture industry over the DFO has been revealed once again. On November 19, 2002, the DFO issued a press release that clumsily attempted to define the collapse of the Area 12 mainland inlet pink salmon as an act of God.

The release lists the top possible causes of the decline in pink salmon returns as:

Flooding and other freshwater events, including excessive pink salmon densities on the spawning grounds and disease outbreaks.

Poor marine survival conditions.

Historic records have shown that in some cases, very high returns of pink salmon in this area have been followed by low returns the next generation. This phenomenon has also been observed elsewhere for pink and other species of salmon.

But a senior DFO scientist reported to the Pacific Fisheries Resource Conservation Council that none of these factors could have caused the demise of the pink salmon.

There was no mortality event in the freshwater.

There was no evidence of poor marine survival, in fact there is considerable evidence to the contrary.

The pattern of decline in no way fits "over-spawn" as it was many orders too great and occurred in rivers with only average returns as well as in ones with exceptional returns.

Last on their list, and qualified by the word "possible," was "impact of sea lice". If I hadn't witnessed the meeting, I might have thought the release fair, as lice are at least mentioned. But detailed reports to the PFRCC by a senior DFO scientist and a biologist are scuttled by the release. I heard reports on what occured in the rivers and the open ocean and on the returns of neighbouring stocks, and can conclude only that the DFO has once again been successfully lobbied by industry at the expense of the commons.

The DFO has a legacy of ignoring its best and most brilliant scientists, arguing in the past that salmon don't need water, as in the case of the Nechako River; and allowing the East coast cod to get smaller every year until extinction was ensured and oil wells could be placed on the Grand Banks.

Alexandra Morton R.P.Bio.

To Express Your View

In view of the life cycle of sea lice, the PFRCC recommended that fallowing of the Broughton fish farms be completed six weeks before pink salmon enter the marine environment. This winter's warmer-than-usual weather means that the first pinks may begin leaving the rivers even earlier than the mid-April date noted by the PFRCC. Therefore, in order to be most effective, the fallowing of the Broughton should be completed by the middle of February. To date, neither the DFO nor the BCMFF has recommended or ordered such action. To express your view, you may wish to write:

Federal Fisheries Minister, The Honorable Robert Thibault, at

and BC Minister of Agriculture, Food and Fisheries, The Honorable John van Dongen, at

Related Links

(1) 2002. Mark Hume. Pink salmon run collapses.

(2) Some Links via Google.


(1) 2002. Advisory: Protection of Broughton Archipelago Pink Salmon Stocks. Report to the BC Minister of Agriculture, Food and Fisheries

(2) 2002. Alexandra Morton interview with Raif Mair. CKNW, Vancouver, B.C., December 4.

(3) 2002. Fisheries and Oceans Canada. News Release.

(4) 1997. Science the State and Freedom of Speech. naturalSCIENCE Commentary.

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