|Scientific Name:||Squatina squatina (Linnaeus, 1758)|
Squalus squatina Linnaeus, 1758
|Taxonomic Source(s):||Linnaeus, C. 1758. Systema naturae per regna tria naturae, secundum classes, ordinus, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata. Impensis Direct, Laurentii Salvii, Holmiae.|
|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 (Regional assessment) ver 3.1|
|Assessor(s):||Ferretti, F., Morey, G, Serena, F., Mancusi, C., Fowler, S.L., Dipper, F. & Ellis, J.R.|
|Reviewer(s):||Dulvy, N.K. & Allen, D.J.|
|Contributor(s):||Buscher, E. & Fordham, S.|
|Facilitator/Compiler(s):||Walls, R.H.L. & Dulvy, N.K.|
Mediterranean regional assessment: Critically Endangered (CR)
The Angelshark (Squatina squatina) was formerly common throughout large areas of coastal and outer continental shelf seas in the Mediterranean and Black Seas. Most of this region is now subject to intense demersal fisheries, and the species is highly catchable from birth onwards. It is taken as bycatch in demersal trawls, set nets, and bottom longlines operating throughout most of its range and habitat. As a result of its slow life history characteristics and bycatch in fisheries with steadily increasing effort and capacity, the Angelshark’s abundance has markedly declined during the past 50 years to the point where it is locally extinct from large areas of the northern Mediterranean Sea. It is now undetectable throughout most of the remainder of its Mediterranean range. The Angelshark is assessed as Critically Endangered under criteria A2bcd+3d on the basis of estimated and suspected past declines of at least 80% over three generations and the likelihood of continuing future declines resulting from fishing pressure.
|Range Description:||The Angelshark is now locally extinct or extremely rare over much of its former Mediterranean range, particularly the northern region (Baino et al. 2001, Ferretti et al. 2005). It once occurred throughout coastal waters of the Mediterranean (at depths between five and 150 m) but its presence can no longer be confirmed in the region as a result of overfishing.|
Native:Turkey (Turkey-in-Asia, Turkey-in-Europe)
Possibly extinct:Albania; Algeria; Bosnia and Herzegovina; Croatia; Cyprus; Egypt (Egypt (African part), Sinai); France (Corsica, France (mainland)); Gibraltar; Greece (East Aegean Is., Greece (mainland), Kriti); Israel; Italy (Italy (mainland) - Native, Sardegna, Sicilia); Lebanon; Libya; Montenegro; Morocco; Palestinian Territory, Occupied; Slovenia; Spain (Baleares, Spain (mainland), Spanish North African Territories); Syrian Arab Republic; Tunisia
|FAO Marine Fishing Areas:|
Mediterranean and Black Sea
The Angelshark was reportedly common, or at least frequently or regularly recorded, throughout much of the Mediterranean Sea during the 19th and early 20th centuries. It was reported as frequent in the Mediterranean Sea during the first half of the 20th century by Lozano Rey (1928). Off the North African coastline, this species may currently be more common than in other parts of the Mediterranean Sea (e.g., off the coast of Tunisia), although it is considered rare in the Gulf of Gabès off Tunisia (Bradaï 2000). Tunisia reported small catches of the Angelshark for a decade towards the end of the 20th century (10–53 tonnes), with 37 tonnes in 1997. Other Mediterranean countries that previously reported 'Angel Sharks' to the Fisheries and Aquaculture Organisation of the United Nations (FAO) with this species as part of the catch included Albania, Turkey, Malta, and France.
Steep population declines have now been reported from large areas of the Mediterranean Sea. Vacchi et al. (2002) reported a steep decline in elasmobranch catch of a tuna trap operating in Baratti (north Tyrrhenian Sea) between 1898 and 1922. For Angel Sharks (Squatina species), catches decreased from an average of 134 specimens from the period 1898–1905, to 95 from 1906–13, and down to 15 from 1914–22. The population became increasingly fragmented and records are now extremely infrequent. The Angelshark has now disappeared from most of its former range in the Mediterranean Sea.
Survey data for this species in the northern Mediterranean Sea exist for the period from 1985–99, when two major trawl surveys were carried out: the International Bottom Trawl Survey in the Mediterranean (MEDITS) and the Italian scientific trawl survey “Gruppo Nazionale Demersali” (GRUND). During MEDITS (1995–99), a broad-scale survey of the northern Mediterranean coastline from west Morocco to the Aegean Sea at depths of 10–800 m, this shark appeared in only two of a total of 6,336 tows, at a depth range of 50–100 m (Baino et al. 2001). In the GRUND survey, captures of this species were reported in only 0.41% of 9,281 hauls (Relini et al. 2000). The Angelshark was reported from trawl surveys carried out in the Adriatic Sea in 1948, but MEDITS data from 1998 indicated possible local extinction from this sea (Jukic-Peladic et al. 2001). Indeed, the last documented catch from the Adriatic Sea was in 1958 (Ferretti et al. 2013), and evidence points to Angel Sharks being absent now from most of the northern Mediterranean coastline.
Historically, Angelsharks were very abundant in the Tuscan Archipelago (D’Ancona and Razzauti 1937, Biagi 1999). From analyses of multiple trawl surveys in the area, Ferretti et al. (2005) detected the disappearance of all Angel Shark species from the area (the Angelshark and Sawback Angelshark, S. aculeata). Out of 22 elasmobranch species modelled, trends in standardised trawl survey catch rates for the Angelshark and Sawback Angelshark displayed the steepest decline (>99% since historical levels). Trawl surveys have not detected the Angelshark in this region since the end of the 1970s (Ferretti et al. 2005).
Decreased catches in the Sicilian channel were detected between 1983 and 1992 from landings records of the Valletta fish market (Fergusson and Marks 1996). Using information from interview surveys, Maynou et al. (2011) suggested that angel sharks became locally extinct in the Catalan Sea before 1959.
Declines have also been reported from studies off the Balearic Islands where this species, previously relatively frequent, may now be absent. It was historically documented in checklists from the region (Delaroche 1809, Ramis 1814, Barceló and Combis 1868, Fage 1907, De Buen 1935), where captures of Angel Sharks were relatively frequent until the 1970s. It then became increasingly sporadic during the 1980s in coastal artisanal fisheries (trammel nets and gillnets), lobster tangle nets, trawl, and bottom longline fisheries. Recently, Massutí and Moranta (2003) reported no captures of Angel Sharks from four bottom trawl fishing surveys (131 hauls, at a depth range of 46–1,800 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 in this area.
According to Ferretti et al. (2005) the Angelshark and Sawback Angelshark displayed the steepest negative rate of population change in the Mediterranean Sea by declining until extinction by >80% over 33 years (approximately three generations).
|Current Population Trend:||Decreasing|
|Habitat and Ecology:|
A temperate-water bottom-dwelling Angel Shark found over the continental shelf, occurring on or near the bottom from close inshore (five metres) in the intertidal or subtidal zone to at least 150 m depth. The Angelshark prefers muddy or sandy substrates and may penetrate estuaries and brackish water.
The Angelshark is live-bearing with yolk-sac only nutrition, and both ovaries functional. It has moderate-sized litters of seven to 25 young, varying according to the size of the female (Tortonese 1956, Bini 1967, Capapé et al. 1990, Ebert and Compagno 2013). Records of size at birth are 24–30 cm TL (Ebert and Compagno 2013) and 24 cm TL (Tortonese 1956, Bini 1967). Gestation period is eight to 10 months (Capapé et al. 1990, Ebert and Compagno 2013); pups are born from December to February in the Mediterranean Sea.
Females reach maturity at 128–169 cm total length (TL), and males at 80–132 cm TL (Lipej et al. 2004). Maximum size is 183 cm TL and possibly up to 244 cm TL (Compagno 1984, Ebert and Compagno 2013), with estimates of <240 cm TL in the Mediterranean Sea (Tortonese 1956). The generation length is inferred to be around 11 years, based on biological information from better known Angel Sharks such as the Clouded Angelshark (S. nebulosa).
|Generation Length (years):||11|
|Movement patterns:||Not a Migrant|
|Use and Trade:||
There is no information on the use and trade for this species from the Mediterranean region.
Angelsharks are highly susceptible to bycatch in trawls because they predominantly lie on the seafloor. Benthic trawl effort has increased in both intensity and efficiency on the shelf and slope area of the Mediterranean Sea over the last 50 years. Earlier population decline at the beginning of the 20th century probably marks the beginning of trawling activity in the Mediterranean Sea. This shark is also caught incidentally in trammel nets and bottom longlines throughout its range, and was formerly the object of targeted fisheries with nets called ‘squanere’ (‘Angel Shark nets’) in parts of the Mediterranean Sea (Marchesetti 1882, Fortibuoni et al. 2010). Human disturbance by habitat degradation and tourism are also possible threats to its preferred sandy near-shore habitat. A low rate of exchange between Angelshark populations may make them especially prone to local depletion as recolonisation will be extremely low.
In 2010, the retention of the Angelshark was prohibited throughout European Union (EU) waters. Angelsharks are protected within three Balearic Islands marine reserves, where fishing for the genus is forbidden.
Parties to the Barcelona Convention agreed in 2012 that the Angelshark be listed in Annex II of the Protocol concerning Specially Protected Areas and Biological Diversity in the Mediterranean Sea - which includes Recommendation GFCM/36/2012/1 – stating that this species cannot be retained on board, transshipped, landed, transferred, stored, sold or displayed or offered for sale, and must be released unharmed and alive to the extent possible.
In 2013, the EU banned the removal of shark fins on board vessels through Regulation No. 605/2013, in line with advice from the International Union for Conservation of Nature Species Survival Commission’s Shark Specialist Group and other shark fishery experts, in order to enhance enforcement of the 2003 EU ban on shark finning (Regulation No. 1185/2003) and facilitate improved shark fishery data collection.
There is an urgent need to confirm the status of this species in the southern Mediterranean Sea and other areas where subpopulations may still persist. If so, appropriate conservation measures are needed to protect this sensitive shark. Further research should be conducted on the population size and trend of the species.
|Citation:||Ferretti, F., Morey, G, Serena, F., Mancusi, C., Fowler, S.L., Dipper, F. & Ellis, J.R. 2016. Squatina squatina. The IUCN Red List of Threatened Species 2016: e.T39332A101695971.Downloaded on 19 September 2018.|
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