The European bass (Dicentrarchus labrax) is a primarily ocean-going fish native to the waters off of Europe's western and southern and Africa's northern coasts, though it can also be found in shallow coastal waters and river mouths during the summer months. It is one of only six species in its family, Moronidae, collectively called the temperate basses. It is both fished and raised commercially, and is considered to be the most important fish currently cultured in the Mediterranean. It is marketed under a variety of names, including "sea dace," "seabass," and "Mediterranean seabass," among others. European bass can reach sizes of up to 1 m (3.3 ft) in length and 12 kg (26 lb) in weight, though the most common size is only about half of that at 0.5 m (1.6 ft). Individuals are silvery grey in color and sometimes a dark-bluish color on the back.
Juveniles form schools and feed on invertebrates, while adults are less social and prefer to consume other fish. They are generally found in the littoral zone near the banks of rivers, lagoons, and estuaries during the summer, and migrate offshore during the winter. Despite being a sought-after gamefish, it is listed as Least Concern by the International Union for the Conservation of Nature because it is widespread and there are no known major threats.
Taxonomy and phylogeny
The European bass was first described in 1758 by Swedish zoologist Carl Linnaeus in his work Systema Naturae. He named it Perca labrax. In the century and a half following, it was classified under a variety of new synonyms, with Dicentrarchus labrax winning out as the accepted name in 1987. Its generic name, Dicentrarchus, derives Greek from the presence of two anal spines, "di" meaning two, "kentron" meaning sting, and "archos" meaning anus. The European bass is sold under dozens of common names in various languages. In the British Isles it is known as the "European bass," "European seabass," "common bass," "capemouth," "king of the mullets," "sea bass," "sea dace," "sea perch," "white mullet," "white salmon," or simply "bass."
|Phylogenetic tree of Moronidae based on the mt-nd6 protein.|
There are two genetically distinct populations of wild European bass. The first is found in the northeast Atlantic Ocean and the second is found in the western Mediterranean Sea. The two populations are separated by a relatively narrow distance in a region known as the Almeria-Oran oceanographic front, located east of the Spanish city of Almería. The exact reason for this separation is unknown, as the geographic divide itself should not account for a lack of gene flow between the two populations. The larval stage of the European bass can last up to 3 months, during which it is unable to swim well, and even a small amount of water flow should transport some individuals between the two regions. In addition, juveniles are able to survive temperature and salinity changes and adults are capable of migrating hundreds of miles.
Distribution and habitat
Its habitats include estuaries, lagoons, coastal waters, and rivers. It is found in the waters in and around Europe, including the eastern Atlantic Ocean (from Norway to Senegal), the Mediterranean Sea, and the Black Sea.It is a seasonally migratory species, moving further inshore and north in summer.
Diet and behaviour
It is mostly a night hunter, feeding on small fish, polychaetes, cephalopods, and crustaceans. They spawn from March to June, mostly in inshore waters. As fry they are pelagic, but as they develop they move into estuaries, where they stay for a year or two.
Fisheries and aquaculture
Annual catches of wild European bass are relatively modest, having fluctuated between 8,500 and 11,900 tonnes in 2000–2009. Most of the reported catches originate from the Atlantic Ocean, with France typically reporting the highest catches. In the Mediterranean, Italy used to report the largest catches, but has been surpassed by Egypt in recent years.
The fish has come under increasing pressure from commercial fishing and has recently become the focus in the United Kingdom of a conservation effort by recreational anglers. The Republic of Ireland has strict laws regarding bass. All commercial fishing for the species is banned and several restrictions are in place for recreational anglers, a closed season May 15 – June 15 inclusive every year, a minimum size of 400 mm, and a bag limit of two fish per day. In a scientific advice (June 2013), it is stressed that fishing mortality is increasing. The total biomass has been declining since 2005. Total biomass, assumed as the best stock size indicator in the last two years (2011–2012), was 32% lower than the total biomass in the three previous years (2008–2010).
European bass was one of the first types of fish to be farmed commercially in Europe. They were historically cultured in coastal lagoons and tidal reservoirs, before mass-production techniques were developed starting in the late 1960s. It is the most important commercial fish widely cultured in the Mediterranean. The most important farming countries are Greece, Turkey, Italy, Spain, Croatia, and Egypt. Annual production was more than 120,000 tonnes in 2010.
- Freyhof, J. & Kottelat, M. 2008. Dicentrarchus labrax. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.2. <www.iucnredlist.org Archived June 27, 2014, at the Wayback Machine.>. Downloaded on 15 February 2014.
- Froese, Rainer and Pauly, Daniel, eds. (2017). "Dicentrarchus labrax" in FishBase. June 2017 version.
- Williams, E. P.; A. C. Peer; T. J. Miller; D. H. Secor; A. R. Place (2012). "A phylogeny of the temperate seabasses (Moronidae) characterized by a translocation of the mt-nd6 gene". Journal of Fish Biology. 80: 110–130. doi:10.1111/j.1095-8649.2011.03158.x.
- Naciri, M.; C. Lemaire; P. Borsa; F. Bonhomme (1999). "Genetic Study of the Atlantic/Mediterranean Transition in Sea Bass (Dicentrarchus labrax)". The Journal of Heredity. 90 (6): 591–596. doi:10.1093/jhered/90.6.591.
- The Pocket Guide to Saltwater Fishes of Britain and Europe
- FAO Yearbook 2009: Fishery and Aquaculture Statistics: Capture Production (PDF). Rome: Food and Agriculture Organization of the United Nations. 2011. p. 138.
- Clover, Charles (2004). The End of the Line: How Overfishing Is Changing the World and What We Eat. London: Ebury Press. ISBN 0-09-189780-7.
- ICES seabass Advice June 2013
- "Dicentrarchus labrax (Linnaeus, 1758 )". Cultured Aquatic Species Information Programme. FAO Fisheries and Aquaculture Department. 2012. Retrieved 12 October 2012.