Meet the Grey Seal

Meet the Grey Seal

Grey Seal (Halichoerus grypus). December 2009. - Neil Aldridge

Discover the world of these magnificent marine mammals with Erin McKeown, Living Seas Trainee at Ulster Wildlife.

Grey seals (Halichoerus grypus), are the larger of the two UK seal species. In fact, grey seals are the largest land breeding mammal in the United Kingdom, with males weighing up to 300kg. The grey seal can be distinguished from the UK’s other seal species, the common seal, by its larger size and longer head. If you can get a close up view you can spot further distinguishing characteristics, with the grey seal nostrils being parallel, rather than v-shaped as in common seals. This might be a clue as to how they got their scientific name Halichoerus grypus – meaning hook-nosed sea pig!

The UK population of grey seals dropped to only 500 individuals in the early 20th century, predominantly due to persecution. However, they’ve made a comeback with an estimated 120,000 grey seals now flourishing throughout the UK. This makes up 40% of the global population! 

In Northern Ireland grey seal numbers are also flourishing. Grey seals around our coasts will spend most of their time at sea, in search of prey. Yet they come ashore in the autumn to form breeding colonies on rocky shores, beaches and on small largely uninhabited islands. For example in Strangford Lough, where a record number of grey seals were recorded during the breeding season in 2019.  

Top sights to see grey seals around our shores include:  

  • Strangford Lough  

  • Cloghy Rocks, Ards peninsula 

  • Rathlin Island  

  • Copeland Islands  

So what do our seals get up to day-to-day? These mammals spend most of their time out at sea hunting alone and being opportunistic feeders eating mainly sand eels, cod, flatfish, crabs and even octopus. Grey seals can dive to depths of around 70 metres when searching for food, with their large eyes allowing them to see well in dark waters and their highly sensitive ears being important for locating prey. 

Meet the grey seal


After spending a summer catching fish, the exciting pupping season for grey seals begins during the autumn. Fluffy white grey seal pups and their mothers remain close during the first weeks of their life. Mothers rarely feed for themselves during this period and lose up to a quarter of their own weight before the pup is ready to be weaned, feeding their young 6 times a day, for up to 10 minutes at a time.

Grey seal pups cannot enter the water for the first 3-4 weeks of their lives. Therefore, when mother seals do return to the sea to hunt, they will leave their pups alone for short periods of time as. If you do see a lone seal pup it is important to not get too close as any disturbance may lead to permanent abandonment from the adult. Instead you can keep a watch from a safe distance.

Other threats

As seals regularly 'haul out' to digest their food or rest, if you do meet one on a beach it is important to give them plenty of space and keep dogs away. If you do find a seal ashore that looks injured or malnourished, observe from a distance. Call Exploris Aquarium in (028) 4272 8062 immediately for further advice and assistance.

Other threats to our grey seals include entanglement in marine litter and ghost fishing gear. Why not participate in a beach clean or simply pick up and safely dispose of any rope or net next time you're at the beach?

Curious local (grey seal) (c) Fran Kennedy

Curious local (grey seal) (c) Fran Kennedy