Seals in Sweden
Sweden is home to three seal species, each with a different ecological niche and method of survival.
Ringed seals are the smallest seal species in Sweden and are only found in the northern Baltic. This species specialises in hunting small crustaceans and fish and is well adapted for its cold home, giving birth in a snow cave on the sea ice to a pup covered in an insulating white coat.
On the western coast and southern Baltic, the harbour seal is found. This species is slightly larger than the ringed seal and is adapted to temperate waters. They give birth on skerries and beaches to pups with a waterproof coat – meaning they’re ready to start building their swimming muscles immediately.
The largest seal species found in Sweden is the grey seal which are common in the Baltic Sea an occasional visitor to the West. Grey seal pups can be born on either land or ice, however they have a better chance of survival on ice. Like the ringed seal, they are born with a fluffy white coat.
Why study seals?
Seals are opportunistic predators, meaning they hunt what prey is available. This helps balance the ecosystem – giving a helping hand to rare species and keeping abundant species in check. In this way, they promote biodiversity and healthy environments. They are also ecosystem sentinels; as they rely on the sea for their survival, problems in seal behaviour or life history are likely indicators of wider problems in the sea. We can learn a lot about the state of our environment by studying seals.
A long road to recovery
All three species were hunted to the verge of extinction in the 1900s before protections were brought in in the 1970s. Over the past fifty years, each species has faced different challenges on its road to recovery. Low pregnancy rates as a result of heavy pollution in the Baltic Sea slowed the growth of both grey and ringed seals up until the early 2000s. Now, these two ice breeding species face habitat losses due to climate change. Harbour seals in contrast showed faster recovery rates in the previous century, however they faced two outbreaks of the deadly ‘seal plague’ caused by Phocine distemper virus which killed an enormous proportion of the population. Now, ongoing research has indicated lower than expected birth rates, possibly because of overfishing of the North Sea.
Send us your photos!
We need your help to identify Sweden's seals by submitting photos to Sälfie ID. You can send us photos through the online form or directly to firstname.lastname@example.org. Be sure to include 1) the location of the photo, 2) the date of the photo, 3) details of the camera used 4) anything else interesting you noticed and 5) if you would like to be notified if this seal is resighted. Remember to keep your distance, seals are easily scared and if approached will make a quick escape into the water – risking injury. So, take photos when seals are already in the water or with a zoom. If a seal is looking directly at you, it has been disturbed and you should move away.
What we look for in photos
We want as much information as we can get, so multiple photographs of the same seal are great, as long as we have the time and date of the sighting. As a rule, if you can zoom in on your photo and see the spot pattern, its good enough to use for an ID. Even if the photographs aren’t that high quality, we can still use them to train AI-powered identification programmes, so they will be put to good use. Some of the most important pieces of information we need are location and date. Be as precise as you can! Knowing the name of the beach or skerry where a sighting occurred is brilliant – but knowing the GPS or what three words coordinates is even better! Similarly if you can provide a time with your photographs we can use that information to tell when seals are most active during the day.
Funded by ASAB