Many people helped researchers with photos of seals

How many photos have you received?

– Since May this year, we have received 243 submissions through the Sälfie-ID homepage. From these submissions we had photos of an amazing 654 seals – most of which were harbour seals but 59 of which were grey seals.

Image

What do you do with the photos now?

– The work to process them will take some time, but so far, we have identified 393 seals with recognizable spot patterns that can be added to the Sälfie-ID database. This means we have already more than doubled the number of seals we can recognize from our earlier work.

– Most submissions were photographs from this year, but many people contributed photos they took earlier – some as far back as 2016. This is extremely valuable to us as it will mean we can check to see if seal behaviour has changed since then. Most submissions were from the Swedish West Coast, but we also had many from the East Coast and even some from Denmark.

In what way have the photos contributed to your research?

– For the past few years, we have seen declines in the numbers of harbour seals born on the West Coast of Sweden. We suspect that this is an indication that the environmental conditions in the North Sea are deteriorating. To study this, we want to know how many seals are hauling out on the coast at different times of the year – the more difficult it is for seals to find food, the less often they will be sighted relaxing on the coast. We started collecting our own photographs of seals to do this in 2022, but we are a small team and can only do targeted field work. Now, thanks to Sälfie-ID, our research can be expanded to understand patterns in haul out behaviour across the entire west coast and even beyond into the Baltic. 

Have you made any particularly interesting discoveries?

– I was surprised at the number of grey seals that were sighted on the West Coast. Grey seals are usually only found in the Baltic but are becoming more common in the Kattegat and Skagerrak. Using a tool like Sälfie-ID, we can now keep track of these changes. We were also alerted to a couple of seals in strange places or sick seals and were able to pass this information on to the county councils and the Swedish Veterinary Agency.

What happens now?

– Now we have some work ahead of us to match the new seals from submissions into our Sälfie-ID database and begin to count resightings. Over time, we will begin to see patterns in seal behaviour and can start to say how this is impacted by changes in the marine environment. For every answer we find about seal ecology we discover two new questions, so will continue our work and ask for new submissions next year.

– We study seals to better understand the health of the ocean, so we are also working closely with experts in at the Gothenburg Global Biodiversity Centre to fit our research into the wider context of marine biodiversity.

Text: Karl-Johan Nylén