When people think of seals in need of protection, they often think about Canada, where Brian Davies fought for decades to take on the culling of the Whitecoats. What is lesser known is that the UK’s seal numbers are declining significantly. In some parts of the UK, Harbour seal numbers have declined by up to 90% since the mid 1990’s (Sea Mammal Research Unit: Harbour Seal Report 2012)
A recent report (Sea Mammal Research Unit: Seal populations, 2014) published by the Sea Mammal Research Unit (SMRU) found that Harbour Seal numbers are declining significantly around the Scottish coast. This decline is particularly evident in Orkney where there has been a 78% decrease in seal numbers since 2000, in Shetland where there has been a 30% decline, and in the Firth of Tay where researchers report a 93% decline in numbers between 2000 and 2013. Recent reports show that such populations are continuing to decline, and migration to other areas is not believed to be a significant factor.
To learn more about the Harbour seal situation, Network for Animals met with scientists from SMRU in St Andrews, Scotland. Dr Ailsa Hall, Dr Bernie McConnell, and Dr Dave Thompson have researched seal populations for decades and believe the decline of populations around Scotland is an incredibly complex issue, which probably can’t be attributed to a single cause.
The scientists suggest that contributing causes of population decline include changes in prey quantity and prey quality, changes in marine habitats (due to activities such as trawling and pollution), increased competition for food from other marine mammals, and to a small degree, the deliberate killing of seals by humans, licenced or potentially unlicenced.
As well as being an important part of the UK’s coastal identity, the disappearance of seals from our shores may have knock-on effects for the food chain, for example to Orca whales which feed on Harbour Seals.
In addition, Jan and Pete Bevington of Hillswick Wildlife Sanctuary in Shetland report that:
[box]
“after nearly 30 years of working with seals, it's very obvious to us that the condition of the harbour seals in particular has been declining. They come in much smaller, with less will to live, which is making it much more work intensive to care for them, especially if they come in premature, which happens regularly these days. Therefore it is important that they receive some form of protection, such as an outright ban on killing harbour seals."
[/box]
The difficulties Harbour Seals are experiencing could therefore be linked to decreased resilience in seal pup populations, reproduction and the overall health of seals and population numbers, which are evidenced at seal sanctuaries.
It is clear that human overfishing of the oceans is having a detrimental effect on marine animals which eat and rely on fish. It is also likely that the pollutants and pathogens that run into the oceans from our rivers are having an impact on the overall health of our marine mammals. The deliberate killing of Scottish seals by commercial salmon farmers is also a factor, but just one issue in a much greater story of human impact on the oceans, which Network for Animals will create pressure to change.
With thanks to Hillswick seal sanctuary, and the Sea Mammal Research Unit.
