Wild salmon numbers have taken a leap in 2010, staging a come-back to levels not seen for two decades, according to a report in The Observer this weekend. That is, except on Scotland’s west coast where salmon are often reared in large floating sea cages.
As The Observer explains: “The major exception to the salmon’s successful return is the west of Scotland, a trend blamed by the Rivers and Fisheries Trusts of Scotland on the prevalence of fish farms, which provide jobs for thousands of workers in the Highlands. Wild salmon catches there have continued to decline while they have risen on the east coast, where there are no salmon farms, says the trust. It blames sea lice infestations from farmed salmon cages for infecting migrating wild salmon.”
This is an issue that has concerned me for the last 20 years. Intensive fish farming has resulted in cheap salmon being readily available in the supermarket. However, the true cost includes the suffering of the farmed fish kept in confinement, as well as the damage to the environment, not least to the wild salmon population.
Dr Alan Wells, policy and planning director of the Association of Salmon Fishery Boards, is quoted in The Observer article as saying: “We can see a clear trend of declining wild salmon catches in areas where the Scottish salmon farming industry operates, in comparison with the east coast”.
Action is clearly needed to reduce the impact of fish farming on wild salmon populations. Intensive fish farming also often raises serious welfare issues, such as overcrowding in barren cages, starvation and the way the fish are slaughtered.
All too often, we hear claims that fish farming is necessary to take the pressure off wild fish stocks, however, the reverse can be true – fish farming can have a direct negative impact on their wild cousins. This can be through infestation with sea lice, a parasitic infestation that can increase death rates, as well as competition from escapees from fish farms themselves. What is less well known is that the farming of carnivorous species, such as salmon and trout, requires more wild fish to produce the equivalent in edible farmed fish. Each tonne of farmed salmon takes three tonnes of wild-caught fish to produce. These are often species such as anchovies, sardines and sandeels, putting these under pressure with a consequent effect on the wider natural food chain.
What often gets overlooked is that farmed salmon are often more polluted than wild salmon – carrying high levels of pesticides. These include lindane, dieldrin, DDT, PCBs, along with a cocktail of other pollution which can pose a cancer risk to people. The wild fish in the diet carry a high pollutant burden and this appears to increase pollutant levels in the salmon, which can then be passed to the consumer.
Here’s how you can help us save fish and stop their suffering on our intensive farms.