|Scientific Name:||Galeorhinus galeus (Linnaeus, 1758)|
|Red List Category & Criteria:||Vulnerable A2bd (Regional assessment) ver 3.1|
|Assessor(s):||McCully, S., Dureuil, M. & Farrell, E.D.|
|Reviewer(s):||Walls, R.H.L. & Allen, D.J.|
|Contributor(s):||Walker, T.I., Cavanagh, R.D., Stevens, J.D., Carlisle, A.B., Chiaramonte, G.E., Domingo, A., Ebert, D.A., Mancusi, C., Massa, A., McCord, M., Morey, G, Lawrence, J., Serena, F. & Vooren, C.M.|
Mediterranean regional assessment: Vulnerable (VU)
Tope (Galeorhinus galeus) is a widespread, mainly coastally distributed species occurring in temperate waters from the surf zone to ~400 m depth. This medium-large demersal shark reaches ~200 cm total length and has a slow life history (30 year generation length) implying slow population turnover. It is fished throughout its range, mainly as bycatch in mixed demersal and pelagic fisheries. Trends from 19 years of survey data of various parts of the Northeast Atlantic suggest this species is declining at a rate that would be consistent with a 38% decline over the three-generation period (90 years). Although few species-specific data are available from Mediterranean waters, declines and disappearances from catch support the inference that similar declines have occurred across both European subregions, given that the subpopulation is believed to be connected between the two and fishing pressure from trawlers is similar. Tope is therefore assessed as Vulnerable in the Mediterranean Sea under criterion A2bd.
Tope is distributed throughout coastal and shelf waters of the Mediterranean Sea (Notarbartolo and Bianchi 1998).
Native: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), Sardegna, Sicilia); Lebanon; Libya; Malta; Monaco; Montenegro; Morocco; Palestinian Territory, Occupied; Slovenia; Spain (Baleares, Spain (mainland), Spanish North African Territories); Syrian Arab Republic; Tunisia; Turkey (Turkey-in-Asia, Turkey-in-Europe)
|FAO Marine Fishing Areas:|
Mediterranean and Black Sea
There is believed to be a single stock of Tope between the Northeast Atlantic and the Mediterranean Sea (ICES 2012). It is suggested that the Northeast Atlantic and Mediterranean stock is isolated from other stocks around the world, with little to no gene flow between them (Chabot and Allen 2009).
This species is now rare in the Mediterranean Sea, and although formerly common in the Adriatic Sea, it has not been captured there in the past half century. The analysis of the International Trawl Survey in the Mediterranean (MEDITS) data from 1994–99 shows a very low frequency of occurrence along the northern Mediterranean continental shelf (0.05%). Tope's overall biomass was estimated to be 0.2 kg/km2 and the standing stock biomass was estimated at 126 tonnes (t; 0.23%; Baino et al. 2001).
Off Italy, Relini et al. (2000) reported catch in only one of the 11 zones studied as part of the Italian national project (9,281 hauls in total, around the Italian coast, from 1985–98); although data on biomass for this species were not provided. Tuna trap data from the northern Tyrrhenian Sea from 1898–1992 show a steep decrease in abundance of catches (80 individuals between 1898 and 1905; only eight for the 1906–13 period and zero from 1914–22) (Vacchi et al. 2002). MEDITS data from the Adriatic Sea were compared with those from the Hvar survey, carried out in 1948 (Jukic-Peladic et al. 2001). Although no data on individual species captured biomass were reported, Tope appeared in the Hvar survey but not in MEDITS. In Tunisian waters, where there exists a lower fishing pressure than along the northern Mediterranean coasts, Tope is still considered to be very rare (Bradaï 2000).
Ferretti et al. (2013) noted that although offshore grounds of the Adriatic Sea remained almost unexploited until the end of World War II, the elasmobranch community surveyed was characterized by small, productive elasmobranchs. Larger, less resilient meso-predatory species such as Tope, which used to be common or seasonally abundant throughout the basin in the 19th and early 20th century (Marchesetti 1882, Paolucci 1901, Ninni 1912, Fortibuoni et al. 2010), were already scarce or undetectable (present in <5% of tows). This is likely due to decades of directed and incidental coastal fishing (Marchesetti 1882, Fortibuoni et al. 2010). The Hvar and Zupanovic surveys that operated in the Mediterranean Sea between 1948 and 1957 caught 18 Tope specimens in the Adriatic Sea, whereas the corresponding surveys since 1957 have never encountered the species again (Ferretti et al. 2013).
No species-specific catch data for the southern Mediterranean Sea were available in 2012 (ICES 2012). Overall, available landings data appeared relatively stable between 1982 and 2003 at around 500 t per year and 400 t per year since 2004, with a drop to 300 t in 2011. However, the absence of some recent national data restricts the interpretation of recent trends. These older survey data suggest early depletion of Tope at least in shallow waters in this area, which could also have occurred in other Mediterranean areas where similar practices historically operated.
Trends from 19 years of survey data of various parts of the Northeast Atlantic suggest this species is declining at a rate that would be consistent with a 38% decline over the three-generation period (90 years). Although few species-specific data are available from Mediterranean waters, declines and disappearances from catch support the inference that similar declines have occurred across both European subregions, given that the subpopulation is believed to be connected between the two and fishing pressure from trawlers is similar.
|Current Population Trend:||Decreasing|
|Habitat and Ecology:|
Tope is most abundant in cold to warm temperate continental seas, from very shallow water to well offshore (Ebert and Stehmann 2013), being primarily found near the bottom but ranges through the water column even into the pelagic zone.
The maximum size recorded is ~200 cm total length (TL) for females in the Mediterranean Sea (Capapé and Mellinger 1988). Differences are also apparent in the size at maturity in different regions. Size at sexual maturity ranges from 120–135 cm TL for males and 134–140 cm TL for females (Olsen 1954, Capapé and Mellinger 1988, Peres and Vooren 1991, Freer 1992), although Ripley (1946) noted the onset of maturity at 150 cm TL for females and McCord (2005) reports that 50% of males are mature at 101 cm TL. The size at maturity of females in European waters was suggested to be 155 cm TL for females and 121 cm TL for males (Dureuil 2013), based on data from the Azores, Madeira (Couto 2013) and the Mediterranean Sea (Capapé and Mellinger 1988).
This shark is live bearing without placenta, with average litters of 20–35 pups; 6–52 observed with an average of 35 in the Northeast Pacific (Ripley 1946, Ebert 2003). Parturition occurs in spring or early summer after a gestation period of ~12 months; the young vary in length at birth between 26 and 40 cm TL, depending on the region. The litter size increases in larger females. These may reflect real differences or may be due to the difficulties of sampling a species, which shows marked temporal and spatial sexual and size segregation, and which makes extensive movements. The generation length of this species is estimated to be around 30 years.
The annual rate of population increase (λ) has been estimated by Cortés (2002) at 1.077 (95% C.I. 1.037 to 1.128) and the natural mortality by Smith et al. (1998) at 0.113 year-1. The intrinsic rate of population increase for the Northeast Atlantic population was estimated at 0.062 year-1 and the natural mortality at 0.094 year-1 (Dureuil 2013), therefore the same may be true for the Mediterranean Sea as the population is believed to be connected.
|Generation Length (years):||30|
|Use and Trade:||Tope has a long history of exploitation in target fisheries in most parts of its range where the species has been in demand for liver oil, meat, and fins.|
Although no direct fisheries for Tope exist in the Mediterranean Sea, it was traditionally caught as bycatch in gillnets and trammel nets in the northern Adriatic Sea, also as bycatch of semi-industrial (Adriatic Sea and Sicily) and artisanal fisheries in pelagic and demersal nets, deep longlines, drift lines, and troll lines (Fischer et al. 1987). A small directed gillnet fishery targeting Mustelus spp. and Squalus spp. operated off the Balearic Islands in the past, which reported catches of Tope. In recent times, only bottom trawl and longline fisheries have reported continuous bycatch of Tope, and such reports are very rare nowadays. The development of the bottom trawl fisheries in the Mediterranean Sea over the first half of the 20th century in the northern range, and during the latter half in the southern range, is considered to be one of the principal factors responsible for the decline of many demersal elasmobranch species. In this sense, both overfishing and habitat degradation must be considered as factors potentially responsible for declines.
In Italian fish markets, the product labeled “palombo” is an umbrella term for numerous shark species, one of which has been identified as Tope (Barbuto et al. 2010). Out of the Triakidae species, only the Common Smoothhound (Mustelus mustelus) is distinguishable from the others, raising concern as to how much Tope is being sold under the label “palombo”. The grouping of species under one name in this manner makes it impossible to deduce landings trends, as individual species trends are masked by those they are grouped with.
In 2013, the EU banned the removal of shark fins on board vessels (CEC 2013), in line with advice from the International Union for the Conservation of Nature’s Shark Specialist Group and other shark fishery experts, in order to enhance enforcement of the 2003 EU ban on shark finning (CEC 2003) and facilitate improved shark fishery data collection.
Tope is listed in Appendix II of the Barcelona Convention, affording it protection from fishing activities taking place in the Mediterranean region. Contracting Parties and Cooperating non-contracting Parties shall ensure that catches of Tope taken with bottom-set nets, longlines and in tuna traps shall be promptly released unharmed and alive to the extent possible, therefore cannot be retained on board, transshipped, landed, transferred, stored, sold, displayed or offered for sale (Recommendation GFCM/36/2012/1). All vessels encountering these species must record information on fishing activities, catch data, incidental taking, release and/or discarding events in a logbook or similar document, then all logged information must be reported to national authorities. Finally, additional measures should be taken to improve such data gathering in view of scientific monitoring of the species.
|Citation:||McCully, S., Dureuil, M. & Farrell, E.D. 2016. Galeorhinus galeus. The IUCN Red List of Threatened Species 2016: e.T39352A16527949.Downloaded on 22 November 2017.|
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