It’s not seals that deserve to be culled on Mayo coastlines, but bad practice
COUNTRYFILE
I FIND it hard to believe that the number of grey seals currently living in and around the Moy estuary constitutes a sustainable population.
Two years ago there were hundreds of the beasts and I had thought they were surely overpopulated, yet now there seem to be more than ever.
Not only are they plentiful, they are becoming quite brazen. In prior times they would head for the water as soon as we stuck our heads over the horizon.
Now they have adopted a nonchalant attitude as if they have lost their fear of man.
One reason for this change in behaviour could be the loss of inherited memory.
In the past humans posed a threat to seals, which have long been seen as competitors for valuable fish stocks.
Indeed, a large adult male grey seal might eat up to 10% of its 600 pounds of body weight each day.
A hundred seals living in an estuary, then, could easily consume a couple of tonnes of fish every day of every week, through most of the year.
This fact has not been lost on those who make a living from fishing.
Historically, seals have been the enemy, something to be eradicated at the first opportunity.
The seal family seemed to understand this well, and did their utmost to stay out of sight or out of range.
At present the culling of seals is outlawed. While the seals appear pretty relaxed with this arrangement, not everybody is happy and there are periodic calls to reduce the number of these animals, especially around the mouths of important salmon rivers such as the Moy.
Anglers and commercial fishermen assume the seals are taking the salmon and sea trout for which the west of Ireland was once famous.
They point to the simultaneous explosion in seal numbers and decline in salmon stocks, and for them the conclusion is obvious.
And it is true that seals do eat salmon. When large numbers of these fish are entering the estuary, what predator would turn them down? And in the spring, when juvenile salmon are heading out from the river to feed in the ocean, losses will also be heavy.
Yet the seals are only present in such large numbers because there is ample prey for them to feed upon. If the amount of available food is reduced, those predators that depend on it will become few.
The recreational sea trout fishery within the Moy estuary is flourishing. There are huge numbers of trout there, waiting to be caught.
These fish are only there because the smaller fishes that they feed upon, such as sandeel and sprat, are also present in huge numbers.
Other fish also gather within the estuary to take their share of baitfish. Pollock and coalfish, whiting, codling, flatfish and bass, together with a great deal more, are present throughout the year.
Both grey and harbour seals, Ireland's only two resident pinniped species, are known to be unfussy when it comes to their food and will happily get by with breakfast, dinner and tea of these lesser species.
Salmon and sea trout are swift, whereas most of the others are more ponderous and far easier to catch.
Analysis of the diet of Irish harbour seals has shown that salmon and trout constituted less than 1% of food consumed.
No doubt this changes from one location to another, and through the seasons as well. Still, the evidence is there that seals are no real threat to salmon and trout stocks.
The real cause of diminishing returns of salmon is a combination of poor water quality, commercial overfishing and the degradation of spawning areas.
It is not seals that deserve to be culled, but bad practice.
(While seals are protected under the EU habitats directive, the government can issue licences to cull them when applications are made to do so).