Canadian Fisheries Data Directly Refutes Seal Cull Myth

The data in DFO’s own report raises the question: If cod mortality does not track to grey seal numbers, how could a reduction in the size of the grey seal population possibly be expected to lead to reduced cod mortality?

A grey seal.

New research recently published in the journal Nature by Canadian scientists from the Bedford Institute of Oceonography and Queens University indicates that some Atlantic groundfish populations, such as cod and haddock, are showing evidence of recovery.

The paper's conclusions - that reversibility of disturbed ecosystems can occur - is fantastic news for depleted fish stocks in Atlantic Canada. What is particularly interesting, however, is that the area showing groundfish recovery - the Eastern Scotian Shelf - is the very same area that supports the highest production of grey seals off Canada's east coast.

This directly challenges the popular belief that grey seals are having a negative impact on Atlantic cod stocks.  

Whoa - what was that? Groundfish can actually increase in the presence of those voracious, fish-eating vermin that Canadian politicians and fishermen love to blame for destroying fish stocks and preventing their recovery?

Yes, that is correct. It now appears that ecosystem recovery may in fact be possible, and even assisted by, the presence of top predators such as grey seals.

These conclusions are not completely surprising, however.

Information that the cod stock biomass was increasing on the Eastern Scotian Shelf and that young cod were showing improved survivorship was presented last October at a Department of Fisheries and Oceans (DFO) workshop on the “Impacts of Grey Seals on Fish Populations in Eastern Canada”.

The data in DFO’s own report raises the question: If cod mortality does not track to grey seal numbers, how could a reduction in the size of the grey seal population possibly be expected to lead to reduced cod mortality?

Additionally, cod stocks appear to be recovering on the Southern Grand Banks  - again, in the presence of the very same grey seals that many claim are impeding their recovery.

On the other side of the Atlantic, researchers examining grey seals and cod in the Baltic Sea determined that fisheries and climate change were likely to affect cod recovery much more than grey seals, and concluded that it is possible to increase populations of cod and grey seals at the same time.

But publicity of the fact that seals and cod can, in fact, co-exist might prove problematic to a Canadian Fisheries Minister intent on spending $35 million on the machine-gunning and incineration of 220,000 grey seals under the guise of helping cod stock recovery.  So in order to downplay such troublesome information, the powers-that-be at the Department of Fisheries and Oceans strategically tasked scientists at the most recent workshop on the impacts of grey seals on fish populations to examine only the negative impacts of grey seals on cod, conveniently ignoring any positive ones.

Still, this latest publication adds to the growing body of scientific research suggesting that predators may not in fact harm groundfish stocks, but that they may actually assist in the recovery of altered marine ecosystems. It certainly lends support to the idea that it is not necessary to cull grey seals - nor any other top predator - to assist with groundfish stock recovery.

At a time when DFO is facing deep budget cuts that will impact services such as marine rescue, the idea of spending millions to kill grey seals is absolutely ludicrous, especially given the lack of evidence that it would actually result in any benefit to fish stocks or fishermen.

Ever since Brian Tobin (wrongly) fingered harp seals for causing the collapse of the cod fishery, promises to kill seals have proven to be a perennial favourite for Atlantic Canadian politicians.

In our rush to reopen commercial fisheries, killing seals continues to be promoted as a quick and dirty solution to problems created by fisheries mismanagement and political ambition.

But now the evidence is appearing that culling seals could have a number of unintended and unexpected consequences.  A cull of grey seals, such as is currently being considered by the Department of Fisheries and Oceans, is not supported by scientific evidence and would be cruel, costly to Canadian taxpayers, and potentially disastrous for marine ecosystems.

--SF

Comments: 4

 
Anonymous
3 years ago

Good news! A cod population on the Scotian Shelf is recovering! Bad news: media twists it to say that all cod populations are recovering, and that we don't need to kill cute seals anymore.
Its easy to twist the words of the author, but if you read carefully the article (yes, it is doable, it just requires a bit of effort), it talks about the interactions between fish, zooplankton, and barely mentions mammal predators. All it says is that we should be careful about drastic measures of controlling populations. We should take the info that media feeds us with a grain of salt, and always have a critical way of seeing things, not just gobble up this info.

 
Anonymous
3 years ago

[...] Source de la Traduction de l’anglais-français . [...]

 
Anonymous
3 years ago

[...] Source de la Traduction de l’anglais-français . [...]

 
Anonymous
3 years ago

[...] This post was Twitted by Hypnotime [...]

Post a comment

Experts

Dr. Ralf (Perry) Sonntag, Directeur national Allemagne
Directeur national Allemagne
Sheryl Fink, Directrice des campagnes pour la faune sauvage, IFAW Canada
Directrice des campagnes pour la faune sauvage, IFAW Canada
Sonja Van Tichelen
Directrice régionale Union européenne