Blue shark

Blue shark

Scientific name: Prionace glauca
It's easy to see where the blue shark got its name from. These sleek, elegant sharks have beautiful metallic blue backs which provide brilliant camouflage out in the open ocean.

Species information


Length: 4m

Conservation status

Globally, the blue shark is listed as Near Threatened on the IUCN Red List. In the UK, it is a Priority Species under the UK Post-2010 Biodiversity Framework.

When to see

June to October


The blue shark is an open-ocean (or pelagic) species that visits UK seas in summer months. In the Atlantic, they appear to follow a clockwise route, following the Gulf Stream to the UK from the Caribbean and returning there following the Atlantic North Equatorial Current. Blue sharks are active predators and feed mainly on small fish and squid - though they have been known to take seabirds and other small sharks too. They even feed on fish that live near the seabed and have been recorded at depths of up to 350m. The largest blue shark ever caught in UK seas weighed a whopping 256lbs (116kg) and measured over 9ft (2.74m).

How to identify

A slim torpedo shaped shark with metallic blue colouration on top and white underneath. They have distinctively long pectoral (front) fins.

In our area

Blue sharks are mainly an oceanic species but are highly migratory and can be found in Irish waters from July to October time. The arrival of these species sharks is often associated with the sea surface temperature reaching 15oC. As the temperatures rise during the Summer months huge shoals of Mackerel arrive , bringing with them Blue Sharks!

When looking for these beautiful sharks Downings and Port-na-blagh in North Donegal are popular blue shark areas. Harbours throughout Cork, Galway and Clare are also key areas for spotting these sharks.


Spotted around the South West coast of England in summer months, normally 10+ miles offshore.

Did you know?

Blue sharks give birth to live babies! The fertilised eggs remain within the mother's uterus where they are nourished by a yolk-sac. Over time, the depleted yolk-sac interlocks with the lining of the mother's uterus which then acts a bit like a mammal's placenta. Blue sharks give birth to an average of 35 pups.

How people can help

If you eat fish then always choose sustainable, local fish. The Wildlife Trusts are working with fishermen, researchers, politicians and local people towards a vision of 'Living Seas', where marine wildlife thrives. Do your bit for our Living Seas by supporting your local Wildlife Trust or checking out our Action Pages.