Seals and Fish
It is a widespread misunderstanding in parts of Canada and elsewhere that the slaughter of seals in Canada is undertaken to protect fish stocks and allow for the recovery of the Atlantic cod.
The fact is cod have been virtually wiped out in the North West Atlantic by commercial overfishing overseen by the Canadian Department of Fisheries and Oceans (DFO) – the very people that tried to put the blame on the seals.
In 1852 it has been estimated that there were 1.26 million tonnes of cod living on the Scotian shelf. Today, the figure is 40,000 tonnes (3% of the 1852 population).
No wonder the population crashed. In 1968 alone 900,000 tonnes of cod were caught in Canadian waters.
For many years the notion of blaming the seals for the disappearance of the fish was promoted by those really responsible. Today many people, particularly in fishing communities in eastern Canada, still believe that the seals are at fault.
The fact is that the seals have been used as a scapegoat.
But extensive research – and common sense – is beginning to destroy the simplistic myth of seals –v– cod. Even the DFO has now moderated its position. In a backgrounder published in February 2003, it says:
‘The current scientific knowledge is insufficient to determine the impact of a seal cull on cod fisheries in the short, medium or long term. Science and resource managers question the value of a cull in a fishery driven by economic market conditions. More importantly, there is no way of knowing how other predators and prey might respond to a decrease in the seal population.’
The truth is that seals eat a range of fish and prey species, some of which themselves eat atlantic cod so a healthy seal population may even help maintain cod populations.
In its document ‘Understanding Seals & Sealing in Canada’ (2002) the DFO says:
‘It is widely accepted in the scientific community that there are many uncertainties in the estimates of the amount of fish consumes by seals. Seals and cod exist in a complex ecosystem, which mitigates against easy analysis or simple solutions to problems such as the lack of recovery of cod stocks.‘
It goes on to estimate the annual consumption by harp seals of their 4 main prey species:
- Capelin (893,000 tonnes)
- Sand lance (350,000 tonnes)
- Arctic cod (186,000 tonnes)
- North Atlantic cod (37,000 tonnes)
It is worth noting that Arctic cod is a predator of North Atlantic cod – the species driven to commercial extinction by human overfishing.
In other words, killing seals may actually hinder the recovery of the atlantic cod in the north east atlantic.
A recent global study shows there is rarely a conflict between marine mammals and commercial fishing as they generally target different species. Marine biologist Kristin Kaschner at the University of British Columbia concludes that 80% of commercial fishing takes place in areas with almost no overlap with marine mammals and that 99% of marine mammal feeding takes place in areas where there is no commercial fishing (New Scientist, 15 May 2004).
‘Marine mammals are not likely to have a large impact on large fisheries’ says Kaschener.