The angel shark is the only representative of the Family Squatinidae off European shores except in the Mediterranean where there are more species. This is a bottom living nocturnal shark which lies concealed or partially buried on sand and mud at depths between 5-90 m in daytime. It is a good swimmer and can cover considerable distances propelling itself with sideways sweeps of its tail. It was formerly a common and important demmersal predator over large areas of its habitat. Angel shark abundance has declined dramatically during the past 50 years to the point where it has been declared extinct in the North Sea and is considered locally extinct over part of its former range in the Irish Sea.

In brief

• Warm-water, bottom dwelling species with its northern limit at Britain and Ireland.
• It prefers sand or mud near shore habitats.
• Very rarely seen due to its severely depleted local population, no recent Northern Irish records.
• Its status is classified as Critically Endangered on the IUCN Red List.
• The main threats are its limiting life history, susceptibility to bycatch, low rate of exchange between populations and habitat degradation.

Species description: Squatina squatina has a distinctive flat body shape with a broad head. Its eyes and large nostril openings are on the upper surface of its head with whisker-like barbels near the nostrils. It has very large pectoral fins with smaller pelvic fins, two dorsal fins and no anal fin. The ends of the pelvic fin reach the origin of the first dorsal fin and both sides of the body are rough. It is usually a greyish or sandy brown colour often with darker markings on top and white on the bottom. It grows to 183 cm and is reported to weigh up to 80 kg with the world rod-caught record at 26 kg. Its food consists mainly of flatfish such as plaice, dabs, soles and also molluscs and crabs.

Life cycle: The female can produce 7-25 young increasing with her size, incubation period is 8-10 months and the young are born between December – February in the Mediterranean, and in July in Britain and Ireland. It is seasonally migratory in colder water moving northwards in summer. Reproductive age, rate of population increase and mortality are unknown.

Similar species: Two other species of Squatina occur in the Mediterranean and nearby Atlantic. S. aculeata is distinguished from S. squatina by a row of conspicuous spines running down its back. S. oculata has large spots on the pectoral fins and on the body towards the tail.

How to see this species: S. squatina was reported to be common or regularly recorded in many areas during the 19th and early 20th centuries. It was particularly common on the south and east coasts of England and was caught in Tralee Bay and Clew Bay in Ireland. The last single capture of angel shark was off the Welsh coast in 1999.
While there is no contemporary evidence or reports of angel sharks in Northern Irish waters in recent times, there are six records of this species in the past between 1890 and 1945. There was a recent (2021) sighting of a juvenile in Welsh waters, suggesting that there is a breeding population in the Irish Sea. There was also a subsequent sighting of a mature individual reported in 2023 from Galway Bay.

Current status: Critically Endangered and populations are severely depleted. Data deficient. Abundance has declined dramatically over the past 50 years and the angel shark has been declared extinct in the North Sea and been eradicated from large areas of the northern Irish Sea.

Why is this species a priority in Northern Ireland?

• Criterion 1: Internationally listed species.
• Criterion 2: Decline based on available data and expert judgement.
• Criterion 3: Rare or restricted range – rare breeding species confined to 5 hectads or less (based on expert judgement).

Threats: As a result of its limiting life history characteristics and bycatch in fisheries with steadily increasing effort and capacity, angel shark abundance has declined dramatically during the past 50 years to the point where it has been declared extinct in the North Sea and is considered locally extinct over part of its former range in the Irish Sea.
Angel sharks are highly susceptible to bycatch in trawls as they lie on the bottom and are large in size. Benthic trawl effort has increased in both intensity and efficiency on the shelf and slope area of the North East Atlantic over the last 50 years. The species is also caught in trammel nets and bottom longlines throughout its range.
A low rate of exchange between Angel shark populations makes them especially prone to local depletion and means that recolonization will be extremely slow. Human disturbance by habitat degradation and tourism are also possible threats to its preferred sandy near shore habitat.

Action: Records of new sites for this species, with details of habitat and population are always valuable. Observations with a photograph can be recorded using iNaturalist, find the MBDP-NI iNaturalist project here.

Alternatively, records can be sent to CEDaR, National Museums Northern Ireland, 153 Bangor Road, Cultra, Holywood, County Down, BT18 0EU. Tel 028 9039 5257, e-mail cedar.records@nationalmuseumsni.org, or via the online portal.

Objectives:

• Any sightings should be reported as a matter of urgency to CEDaR but exact location should not be disclosed publicly.
• Anglers should adopt the catch-and-release programme and any bycatch should be returned to the sea, preferably after being tagged if appropriate training has been completed.
• Incidental bycatch should not be landed but returned to sea.
• Increase the number of viable populations of the species
• Increase the range of the species.
• Establish appropriate management on appropriate historical sites.

Conservation:

• On OSPAR List of Threatened and/or Declining Species and Habitats.
• European Community Action Plan for the Conservation and Management of Sharks went out for consultation in 2008 and was adopted in 2009.
• Protected under Wildlife (NI) Order Schedule 5.
• Listed as Critically Endangered on Irish, European and Global Red List.

Distribution Map from NBN: Squatina squatina at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Squatina squatina at iNaturalist World Species Observations database.

WoRMS: Squatina squatina at World Register of Marine Species. Accepted name: Squatina squatina (Linnaeus, 1758). AphiaID: 105928.

Classification: Biota; Animalia; Chordata; Vertebrata; Gnathostomata; Chondrichthyes; Elasmobranchii; Neoselachii; Selachii; Squalomorphi; Squatiniformes; Squatinidae; Squatina