|Scientific Name:||Dentex dentex (Linnaeus 1758)|
Dentex vulgaris Valenciennes, 1830
Sparus dentex Linnaeus, 1758
|Taxonomic Notes:||Genetic analysis of the geographical partitioning revealed that this species showed an Atlantic-Mediterranean partitioning (Patarnello et al. 2007) indicating that exchanges between subpopulations are reduced and may limit rescue effects from migration and dispersal from other subpopulations to compensate for impacts of direct exploitation.|
|Red List Category & Criteria:||Vulnerable A2bd ver 3.1|
|Assessor(s):||Carpenter, K.E. & Russell, B.|
|Reviewer(s):||de Morais, L., Pollard, D. & Lindeman, K.|
|Contributor(s):||Bizsel, K., Di Natale, A. & Francour, P.|
|Facilitator/Compiler(s):||Gorman, C. & Comeros-Raynal, M.|
Dentex dentex is widespread from the British Isles to Cape Blanc, Mauritania. Dentex dentex is highly vulnerable to overfishing as it exhibits life history characteristics including longevity, large body size and slow growth. Its vulnerability is exacerbated by its high commercial value. This species is also very sensitive to the effects of protection as shown by its abundance within protected areas in the Mediterranean and its scarcity outside of them, indicating that D. dentex is conservation dependent. Global landings of this species increased substantially in the 1970s and 1980s but declined by over 30% in the early 1990s. Similar trends were observed in the Mediterranean and West African catches. These regions are major components of D. dentex landings and have declined by 37% and over 70%, respectively. There is no evidence of a decline in effort from these regions. This species is assessed as Vulnerable in the Mediterranean and Europe, which comprise more than half of this species' range. Global population declines for D. dentex are estimated to have exceeded 30% within the past three generations (=36 years). It is therefore listed as Vulnerable under criterion A2bd.
The Mediterranean Sea comprises a large part of the range for D. dentex in the region and it is estimated that the population has declined at least 50% within three generation lengths, and fishing effort is not expected to decrease in the near future. Therefore this species is listed as Vulnerable.
|Range Description:||Dentex dentex is widely distributed along the West African coast north of Cape Blanc, Mauritania; around the Canary Islands (Dooley et al. 1985), Madeira (Wirtz et al. 2008) and south to Senegal (Bauchot and Hureau 1986). This species is also present throughout most of the Mediterranean Sea, most frequently south of 40°, occasionally in part of the Black Sea (Marengo et al. 2014), and in the northeastern Atlantic northwards to the British Isles (Carpenter FAO ECA Guide in press.). The depth range for this species is one to 200 m (Bauchot and Hureau 1990, Lloris 2002, Marengo et al. 2014).|
Native:Albania; Algeria; Bosnia and Herzegovina; Bulgaria; Croatia; Cyprus; Egypt; France; Gibraltar; Greece; Ireland; Israel; Italy; Lebanon; Libya; Malta; Monaco; Montenegro; Morocco; Portugal (Madeira); Romania; Slovenia; Spain (Canary Is.); Syrian Arab Republic; Tunisia; Turkey; Ukraine; United Kingdom; Western Sahara
|FAO Marine Fishing Areas:|
Atlantic – northeast; Atlantic – eastern central; Mediterranean and Black Sea
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||According to FAO Fisheries Statistics (2011), global landings since 1975 show an overall decline in D. dentex catches. Catches increased rapidly through the 1980s and early 1990s until dropping substantially from 10,101 tonnes in 1992 to a low of 1,294 tonnes in 1998. The average global decline since 1992 is about 36%. The Mediterranean catch contributes ~45% of the global catch, while the West African and the Northeast Atlantic catches comprise 35% and 18%, respectively. Mediterranean catches also show an overall decline since 1975, peaking in 1990 at over 6,000 tonnes and subsequently declining to less than 1,000 tonnes by 1999, and then rising slightly to 1,147 tonnes in 2011. In the Mediterranean, average catches declined by about 37% since 1990. In West Africa, catches are also in decline, peaking in 1992 at 5,009 tonnes and then declining to less than 50 tonnes by 2010, indicating an average decline of over 70%. |
The only stock assessment studies available for this species were conducted in Tunisia. The stocks were addressed according to different regions: Northern, Eastern and South (Chemmam-Abdelkader 2004, FAO 2008). The northern stock was assessed as under-exploited, the Eastern was optimal, and the Southern region was strongly over-exploited (Chemmam-Abdelkader 2004). Fishing in the Southern region is carried out on small size classes and is comprised of mainly juveniles (Chemmam-Abdelkader et al. 2007) with the average age of the stock at 1.9 years which is very low considering the longevity of D. dentex (Chemmam-Abdelkader et al. 2007).
There has been a significant population decline in Turkey (Fricke et al. 2007). The recovery time in Mediterranean marine protected areas has been slow, around 10 years (P. Francour pers. comm.).
|Current Population Trend:||Unknown|
|Habitat and Ecology:||Dentex dentex is littoral and benthopelagic, it lives on rocky bottoms, Posidonia oceanica meadows, sandy habitats with Caulerpa and Cymodocea and in the coralligenous community, down to 200 m, but mainly between 15–50 m (Fischer et al. 1987, Ramos-Esplá and Bayle-Sempere 1991, Abellán 2000, Guidetti 2000, Rueda and Martinez 2001, Ballesteros 2006, Stobart et al. 2012). It is common at depths of 60 m, but is also found to 100 m (Morales-Nin and Moranta 1997). Adults are solitary, the young gregarious. Juveniles inhabit shallow water to four metres depth between Posidonia oceanica meadows and sand and close to crevices and small caves (Dulčić et al. 2002; Valle and Bayle-Sempere 2009). This species feeds on fishes, molluscs and cephalopods (Frimodt 1995). This species can reach over one meter in length (Fischer et al. 1987) and weigh up to 13 kg, although most catches average 35 to 40 cm (Bauchot and Hureau 1986, Ramos-Esplá and Bayle-Sempere 1991). The maximum lifespan appears to be approximately 20 years (Morales-Nin and Moranta 1997), although longevity has been reported up to 33 years (Chemmam-Abdelkader et al. 2004). No major differences in morphology or length/weight ratios were observed between males and females (Rueda and Martinez 2001). Growth proceeds at a fast pace during the first two years, with animals reaching around 24 cm at one year, with their growth slowing down during adulthood (Morales-Nin and Moranta 1997). Growth rates of D. dentex are not affected by the reproductive period (Morales-Nin and Moranta 1997). In all likelihood, the large adult size of the species reduces the number of potential predators (Morales-Nin and Moranta 1997). Relative fecundity for D. dentex can range from 32,000 to 393,000 eggs/kg body weight, and a positive linear relationship between batch fecundity and body size was found (Loir et al. 2001). |
It is a gonochoristic species, with spawning taking place between the end of March and May. Males and females older than one year mature almost simultaneously. The length at 50% maturity for females of this species from the Balearic Islands is estimated at 36.4 cm and 52.02 cm for males (Morales-Nin and Moranta 1997), and 23.32 cm for males and 22.58 cm for females from the Tunisian coast (Chemmam-Abdelkader 2004). Sexually mature females were detected at a minimum standard length of 21 cm in culture (Loir et al. 2001). Sexual maturation and reproduction occur between an age of two and four years (Riera et al. 1993, Abellán et al. 1997, Morales-Nin and Moranta 1997). This species is suspected to spawn in the Bay of Biscay (Quéro et al. 2009) and information from Corsica suggests that during the spawning period, the populations of D. dentex gather periodically on spawning sites at 40–100 m depth to form shoals. The spawning sites of this species are usually hard substrates such as rocky outcrops or wrecks and mating usually occurs during the day but may also take place at night during a full moon (Marengo et al. 2014).
Generation length for D. dentex is estimated to be 12 years, using the following equation for a gonochoristic fish species: Generation length = Σxlxmx/Σlxmx
|Generation Length (years):||12|
|Use and Trade:||
Dentex dentex is a highly valued table fish in the Mediterranean region and is a component of commercial, artisanal and recreational fisheries. Its fishery is mainly commercial and artisanal and it is caught with beach seines, trawl nets, gill nets, trammel nets, bottom long-lines, and hand lines. It is regularly present in the markets of Spain, Italy, Greece, Turkey, Cyprus, Tunisia and Morocco, and also occasionally in France, but rarely in Israel. Greece, Turkey, Italy, Tunisia and Spain account for about 90% of landings (Basurco et al. 2011). It is sold fresh or frozen (Fischer et al. 1987) and is also used for fishmeal and oil in the Eastern Central Atlantic (Carpenter FAO ECA Guide in press). Current prices for this species range from 15 €/kg for a whole fish to 38 €/kg for fillets and sliced fish (Marengo et al. 2014). Some attempts to culture this species have been successful on a trial basis, in Greece, Italy and Spain (Rueda and Martínez 2001) and it has a high specific growth rate and spawns spontaneously. Two countries (Bosnia and Herzegovina and Spain) have reported aquaculture production to FAO for this species (Basurco et al. 2011).
This species is also caught at bycatch, especially juveniles, by trap nets, fyke net, basket traps, bottom-trawl, purse and beach seines, as well as "Tramata" fishing used in the eastern Adriatic and "Gangui" fishing used along the northern coast of the Mediterranean (Cetinić et al. 2002, Akyol 2003, Quéro et al. 2009, Vandeperre et al. 2006, Sacchi et al. 2010).
|Major Threat(s):||This species is an important food fish and overexploitation and eutrophication are considered threats in parts of its range. Dentex dentex is highly vulnerable to fishing due to its life history characteristics including its longevity, large size and slow growth (Garcias-Rubies and Zabala 1990, Garcia-Rubies et al. 2013). There has been an increase in demand for this species in Turkey in the 1980s and 1990s due to increases in coastal tourist resorts and restaurants (K. Bizsel pers. comm.).|
|Conservation Actions:||This species occurs in marine protected areas in many parts of the Mediterranean Sea. This species is very sensitive to the effects of protection, with its being population considerably higher within the Medes Islands Marine Reserve in Spain and rarely observed outside of this protected area (Macpherson et al. 2002, Garcia-Rubies et al. 2013). As the Southern D. dentex stock off Tunisia is strongly overexploited, it is recommended that fishing effort should be reduced to 44% compared with the optimal level (Chemmam-Abdelkader et al. 2007). Restrictions on spear fishing and the establishment of minimum legal sizes have been recommended (A. Di Natale, Acquario di Genova, pers. comm.). Other recommendations include enforcement of minimum catch sizes in areas where they are already established (e.g. 20 cm in Turkey; K. Bizsel, Dokuz Eylul University, pers. comm.). Additional management regulations such as catch limits, seasonal closures, a minimum landing size or the expansion of no-take locations in critical areas (Lloret et al. 2008, Abdul Malak et al. 2011), are recommended for this species given its heavy exploitation by commercial and recreational fishers. Although some countries have implemented a minimum landing size, depending on the country, it remains well below the size at 50% maturity (Morales-Nin and Moranta 1997, Marengo et al. 2014). Region specific population genetics information may be useful for the management of this species.|
|Citation:||Carpenter, K.E. & Russell, B. 2014. Dentex dentex. The IUCN Red List of Threatened Species 2014: e.T170245A1300534.Downloaded on 20 July 2018.|
|Feedback:||If you see any errors or have any questions or suggestions on what is shown on this page, please provide us with feedback so that we can correct or extend the information provided|