|Scientific Name:||Squatina squatina|
|Species Authority:||(Linnaeus, 1758)|
|Taxonomic Notes:||Squatina squatina is difficult to identify to species level, therefore many of the records from fishermen reports in the Mediterranean are often assigned only to genus level, though this is the only angel shark known from northern European seas.|
|Red List Category & Criteria:||Critically Endangered A2bcd+3d+4bcd ver 3.1|
|Assessor/s:||Morey, G., Serena, F., Mancusi, C., Fowler, S.L., Dipper, F. & Ellis, J.|
|Reviewer/s:||Cavanagh, R.D., Valenti, S.V. & participants of the Shark Specialist Group Northeast Atlantic workshop (Shark Red List Authority)|
This large stocky angel shark was formerly a common and important demersal predator over large areas of its coastal and outer continental shelf sediment habitat in the Northeast Atlantic, Mediterranean and Black Seas. Most of this region is now subject to intense demersal fisheries, and the species is highly vulnerable from birth onwards to bycatch in the benthic trawls, set nets and bottom longlines operating through most of its range and habitat. As a result of its limiting life history characteristics and bycatch in fisheries with steadily increasing effort and capacity, its abundance has declined dramatically during the past 50 years to the point where it has been declared extinct in the North Sea and has apparently been extirpated from large areas of the northern Mediterranean. It is now extremely uncommon throughout most of the remainder of its range, with the possible exception of some areas of the southern Mediterranean and Canary Islands where its status should be confirmed and conservation measures introduced as a matter of urgency.
|Range Description:||Original range from Scandinavia to North-western Africa (Mauritania and the Canary Islands), including the Mediterranean and Black Seas. Current distribution appears to be reduced from this historic range, as a result of severe population depletion, local extirpations, and some contraction in range; for example it is now considered to be extinct in the North Sea (ICES ACFM 2005) and is no longer encountered in most areas of the northern Mediterranean.|
Native:Albania; Algeria; Belgium; Bosnia and Herzegovina; Bulgaria; Croatia; Cyprus; Denmark; Egypt; France (Corsica); Georgia; Germany; Greece; Ireland; Israel; Italy (Sardegna); Mauritania; Montenegro; Netherlands; Norway; Portugal; Romania; Russian Federation; Slovenia; Spain; Sweden; Syrian Arab Republic; Tunisia; Turkey; Ukraine; United Kingdom; Western Sahara
|FAO Marine Fishing Areas:||
Atlantic – eastern central; Atlantic – northeast; Mediterranean and Black Sea
|Range Map:||Click here to open the map viewer and explore range.|
Squatina squatina was reported to be common, or at least frequently or regularly recorded in many areas, during the 19th century and early 20th centuries. For example, It was particularly common on the south and east English coasts (Yarrell 1836, Day 1880?04), and also common in the North Sea, on the Dogger Bank, in the Bristol Channel and Cornwall, and ?by no means uncommon? in the Firth of Clyde (Day 1880?4). Historically it has also been caught in Tralee Bay and Clew Bay, Ireland. It was still being caught regularly and considered common in the UK at the beginning of the 20th century (Garstang 1903). Although more common off the Atlantic Iberian coasts, Squatina squatina was also reported as frequent in the Mediterranean during the first half of the 20th century by Lozano Rey (1928). Steep population declines have, however, now been reported from several parts of this species? range, including in the North Sea (ICES ACFM 2005) UK coastal waters (Rogers and Ellis 2000), the French coast (Quero and Cendrero 1996, Capapé et al. 2000), and large areas of the Mediterranean (e.g., Vacchi et al. 2002). During the early 1900s, an average of one specimen was taken during every ten hours of trawl survey, but in recent years the species has virtually vanished (Rogers and Ellis, 2000). CEFAS surveys recorded angel sharks in low numbers in Cardigan Bay during the 1980s (Ellis et al. 1996) but report just one individual in the last 15 years. The population is clearly becoming increasingly fragmented and records are now extremely infrequent (for more information, see ?Threats?). It has now virtually disappeared from much of its former range in the Northeast Atlantic and Mediterranean. Off the North Africa coastline the species may be more common, e.g., as reported off the coast of Tunisia (although it is considered rare in the Gulf of Gabès) (Bradai 2000).
Vacchi et al. (2002) reported the dramatic decline in the elasmobranch catch of a tuna trap operating in Baratti (Northern Tyrrhenian Sea) between 1898 and 1922. For the genus Squatina, catches decreased from an average of 134 specimens from the period 1898 to 1905, to 95 between 1906 and 1913, and down to 15 between 1914 and 1922.
Declines have also been reported from studies off the Balearic Islands where this species, previously relatively frequent, may now be absent. Off the Balearic Islands Squatina squatina was historically documented in checklists (Delaroche 1809, Ramis 1814, Barceló I Combis 1868, Fage 1907, De Buen 1935). Captures of S. squatina spp. were relatively frequent until the 1970?s, becoming increasingly sporadic during the 1980?s in coastal artisanal fisheries (trammel nets and gillnets), lobster tanglenets, trawls and bottom longline fisheries. Since the mid 1990?s no reports of Squatina spp. have been reported in the area (Gabriel Morey, pers. comm). Recently, Massutí and Moranta (2003) reported no captures of Squatina spp. from four bottom trawl fishing surveys (131 hauls, at a depth range of 46 to 1,800 m) carried out between 1996 and 2001 around the Balearic Islands. In addition, the likely low interaction with stocks from other areas further affects the already low recovery capacity of isolated populations such as those around the Balearics.
Catch data for this species in the north Mediterranean exist for the period from 1985 to 1999, when two major trawl surveys were carried out: the Mediterranean International Trawl Survey (MEDITS) and the Italian National Project (National Group for Demersal Resource Evaluation (GRUND)).
During the MEDITS program (1995?1999), a broad scale survey of the north Mediterranean coastline from west Morocco to the Aegean Sea in depths of 10 to 800 m, S. squatina appeared in only two of a total of 9,095 tows, at a depth range of 50 to 100 m, resulting in an estimated standing biomass of 14 t throughout the survey area (Baino et al. 2001), which equates to 1,400 individuals assuming an average individual weight of 10 kg.
In the Italian survey, captures of S. squatina were reported in only 0.41% of 9,281 hauls (Relini et al. 2000). Squatina squatina was reported from trawl surveys carried out in the Adriatic Sea in 1948, but MEDITS trawls in 1998 indicated this species may now be absent from this area (Jukic-Peladic et al. 2001). Indeed, evidence points to angel sharks being absent nowadays from most of the northern Mediterranean coastline.
Landings in the Northeast Atlantic compiled by WGEF (2004) from 1978 to 2002 for all ICES Areas are variable because of recent misreporting of other species (primarily Lophius) as this non-quota species. After deleting these records, landings have declined from 15 to 20 t in the 1980s, to 1 to 2 t in the 1990s, with the last reported landing in 1998.
|Habitat and Ecology:||
A temperate-water bottom-dwelling angel shark of the European and North African continental shelves, occurring on or near the bottom from close inshore (5 m) in the intertidal or subtidal zone to at least 150 m depth. This shark prefers mud or sandy bottom, where it lies buried with little more than its eyes protruding. It may penetrate estuaries and brackish water. The angelshark is nocturnal and can be found swimming strongly up off the bottom at night, but is torpid in the daytime and rests on the bottom. In the northern parts of its range the angelshark is seasonally migratory, and makes northwards incursions during the summer. (Compagno in prep.).
Most life history data were provided by Capape et al. (1990) for the Mediterranean. Females reach maturity at 128 to 169 cm, and males at 80 to 132 cm (Lipej et al. 2004), with maximum sizes of 183 cm and possibly up to 244 cm (Compagno 1984, in prep.), with estimates of less than 240 cm in the Mediterranean Sea (Tortonese 1956). Age at maturity and longevity are unknown. This shark is ovoviviparous, with both ovaries functional. It has moderate-sized litters of 7 to 25 young which vary according to the size of the female (Tortonese 1956, Bini 1967, Capapé et al. 1990, Compagno in prep). Records of size at birth are 24 to 30 cm (Compagno in prep.) and 24 cm (Tortonese 1956, Bini 1967). Gestation period is 8 to 10 months (Capapé et al. 1990, Compagno in prep.), born in December to February in the Mediterranean but apparently later in northern parts of its range (July in England). Reproductive age and periodicity, rate of population increase and mortality are unknown.
The angelshark feeds primarily on bony fishes, especially flatfishes (Ellis et al. 1996) but also other demersal fishes and skates, crustaceans and molluscs. Specific items include hake (Merlucius merlucius, Merluciidae), sparids (Pagellus erythrinus, Sparidae), grunts (Pomadasys sp., Haemulidae) flatfish (Bothus sp., Bothidae, Citharus linguatula, Citharidae), sole (Solea solea, Soleidae), squid (Loligo vulgaris), cuttlefish (Sepia officinalis, Sepiola spp.), and crustaceans (Dorippe lanata, Geryon tridens, Dromia vulgaris, Goneplax rhomboides, Macropipus corregatus, Atelecyclus rotundatus). It occasionally swallows odd items, including eelgrass and seabirds (a cormorant was once recorded) (Compagno in prep.).
Angel sharks are highly susceptible to bycatch in trawls as they lie on the bottom. Benthic trawl effort has increased in both intensity and efficiency on the shelf and slope area of the Northeast Atlantic and Mediterranean over the last 50 years. The species is also bycaught in trammel nets and bottom longlines throughout its range. Human disturbance by habitat degradation and tourism are also possible threats to its preferred sandy nearshore habitat.There is evidence for dramatic declines from historic data from a tuna trap operating in the Northern Tyrrhenian Sea with catches of the genus Squatina reported at an average of 134 specimens from 1898 to 1905, down to 15 between 1914 and 1922 (Vacchi et al. 2002). This early decline probably marks the beginning of trawling activity in the area, to which angel sharks are highly susceptible. A low rate of exchange between Squatina populations may makes them especially prone to local depletion and means that recolonisation will be extremely low.
Tunisia reported small catches of this species during the past decade (10 to 53 t), with the 1997 catch at 37 t; other Mediterranean countries that report 'angelsharks' to FAO with this species as part of the catch include Albania, Turkey, Malta and France. Landings in the Northeast Atlantic collated by WGEF (ICES 2004) may include some misreporting of other (quota) species (e.g., Lophius) as angel shark is a non-quota species, but otherwise landings have declined from an average of 17 t/annum in the 1980s, to 1 to 2 t in the 1990s.
The genus Squatina is protected within three Balearic Islands marine reserves, where fishing for these species is forbidden. Squatina squatina was proposed for strict protection under the UK Wildlife and Countryside Act in 2001; a decision is still (2006) awaited from government [Update by LRH May 27th 2010 - species now listed under UK Wildlife and Countryside Act, and will be protected against killing, injuring or taking (section 9(1)) on land and up to 3 nautical miles (nm) from English coastal baselines]. UK and Belgium proposed S. squatina for listing on the OSPAR Priority List of Threatened and Endangered Species, and although the proposal was deemed appropriate by the Study Group on Elasmobranch Fishes (ICES, 2002), the nomination was not accepted. Squatina squatina is listed on Annex III of the Barcelona Convention.
There is an urgent need to confirm the status of this species in the southern Mediterranean, Canary Islands and other areas where populations may still persist. If so appropriate conservation measures are needed to protect this species there.
|Citation:||Morey, G., Serena, F., Mancusi, C., Fowler, S.L., Dipper, F. & Ellis, J. 2006. Squatina squatina. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.2. <www.iucnredlist.org>. Downloaded on 07 March 2014.|
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