Blue skate

What it is

The blue skate is a large ray with a rhombic body shape and a pointed snout. Its upper surface is olive-grey or brown, often marked with spots, while the underside is a lighter blue-grey. A row of spines runs along its tail, typically featuring one or two interdorsal thorns. This cartilaginous fish can grow up to 1.43 metres in length. It belongs to the family Rajidae and was historically grouped with the flapper skate under the name common skate.

Where it lives

This species inhabits the northeast Atlantic Ocean, ranging from Norway and Iceland down to Senegal. Its presence in the Mediterranean Sea is uncertain due to confusion with related species. Blue skates are bottom dwellers that prefer soft seabeds but also live over gravel and rock. They are usually found at depths between 100 and 200 metres, though they can occur as shallow as 30 metres or as deep as 1,000 metres. Populations are now fragmented and depleted across much of this range.

How it lives

As a bottom feeder, the blue skate eats crustaceans, clams, oysters, snails, and worms. It also consumes cephalopods and small to medium-sized fish like sand eels and flatfish. Larger individuals eat bigger prey to sustain their size. While mostly benthic, some skates ascend rapidly from the seabed to catch pelagic fish such as mackerel and herring. Diet varies with size and activity levels. The sex ratio is generally equal, though it may shift based on location and season.

Breeding and life cycle

Blue skates mature slowly, reaching sexual maturity at around 11 years of age. Males mature at about 1.15 metres and females at 1.23 metres. They reproduce only every other year after reaching maturity. Mating occurs in spring, and females lay approximately 40 egg cases during the summer in sandy or muddy flats. These egg cases are up to 25 centimetres long and covered in felted fibres. Eggs develop for two to five months before hatching into juveniles measuring up to 22.3 centimetres.

Fish and people

Fisheries have historically targeted this skate, and it remains vulnerable to incidental capture as bycatch in trawl nets. The species is strictly protected within the European Union, making it illegal for commercial fishers to target or retain it. If caught accidentally, it has a good chance of survival if released. Despite protection, overfishing has caused drastic population declines. It is no longer found in the Baltic Sea. Strongholds remain off western Scotland and in the Celtic Sea.

Status and threats

The International Union for Conservation of Nature lists the blue skate as critically endangered. Its population has collapsed due to direct fishing and bycatch. Recovery is slow because the species lives for up to 100 years and matures late. However, studies of related skates suggest recovery might be possible if pressures are reduced. Misidentification with other skates complicates conservation efforts. Previous records in Norway and the Mediterranean may refer to different species.

Questions people ask about Blue skate

Good reading and sources

• BBC NewsBBC, Article

• Blue skate on WikipediaEncyclopedia
• More photos on Wikimedia CommonsPhotos
• Wikidata recordOpen data