41-586: The European sea sturgeon ( Acipenser sturio ), also known as the Atlantic sturgeon or common sturgeon , is a species of sturgeon native to Europe. It was formerly abundant, being found in coastal habitats all over Europe . Most specifically, they reach the Black and Baltic Sea. It is anadromous and breeds in rivers. It is currently a critically endangered species. Although the name Baltic sturgeon sometimes has been used, it has now been established that sturgeon of
82-553: A combination of habitat destruction , overfishing, and pollution. No species is known to naturally occur south of the equator, though attempts at sturgeon aquaculture are being made in Uruguay , South Africa , and other places. Most species are at least partially anadromous , spawning in fresh water and feeding in nutrient-rich, brackish waters of estuaries or undergoing significant migrations along coastlines. However, some species have evolved purely freshwater existences, such as
123-831: A comprehensive report on the quality of the marine environment of the North-East Atlantic. This was supported by five smaller reports on the different parts of the OSPAR maritime area –the Arctic , the Greater North Sea , the Celtic Seas, the Bay of Biscay/Golfe de Gascogne and Iberian waters , and the Wider Atlantic . According to the fr :Association pour le contrôle de la radioactivité dans l'Ouest , if tritium and iodine 129 discharges from
164-598: A considerable risk to the recovery of self-sustaining populations, necessitating targeted conservation measures to address the issue and mitigate its impact. The extraction of gravel in the Garonne river in France and Spain poses a potential threat to European sea sturgeon populations. This activity, along with dam construction, contributes to habitat degradation, impacting the availability of suitable spawning and feeding sites. Preservation of these critical habitats becomes essential for
205-555: A derived one; sturgeon ancestors had bony skeletons. They also lack vertebral centra , and are partially covered with five lateral rows of scutes rather than scales . They also have four barbels —sensory organs that precede their wide, toothless mouths. They navigate their riverine habitats traveling just off the bottom with their barbels dragging along gravel, or murky substrate. Sturgeon are recognizable for their elongated bodies, flattened rostra , distinctive scutes and barbels, and elongated upper tail lobes. The skeletal support for
246-426: A long evolutionary history culminating in the most familiar fishes, past adaptive evolutionary radiations have left only a few survivors, such as sturgeons and gars . The wide range of the acipenserids and their endangered status have made collection of systematic materials difficult. The factors have led researchers in the past to identify over 40 additional species that were rejected by later scientists. Whether
287-545: A sharp decline due to overfishing (which greatly accelerated from the second half of the nineteenth century onwards) led to their disappearance from the vast majority of their former range. They have been a protected species in Europe since 1982. Despite their estimated range of distribution, they have become so rare that they only breed in the Garonne river basin in France. Conservation projects involving this species include reintroductions based on specimens from aquaculture with
328-532: A sister to A. dabryanus . The family contains 8 extinct fossil species and 28 extant species/subspecies (include 1 species of Sterlet and 2 species of living fossils), in 4 genera. This list uses the original classification scheme: Family Acipenseridae Sturgeon range from subtropical to subarctic waters in North America and Eurasia . In North America , they range along the Atlantic Coast from
369-733: Is likewise a combination of "Oslo" and "Paris". The Convention for the Protection of the Marine Environment of the North-East Atlantic was opened for signature at the Ministerial Meeting of the Oslo and Paris Commissions in Paris on 22 September 1992. The Convention has been signed and ratified by all of the Contracting Parties to the original Oslo or Paris Conventions ( Belgium , Denmark ,
410-511: Is processed into the luxury food caviar . This has led to serious overexploitation , which combined with other conservation threats, has brought most of the species to critically endangered status, at the edge of extinction . Acipenseriform fishes appeared in the fossil record some 174 to 201 million years ago by Nathan, during the Early Jurassic , making them some of the earliest extant actinopterygian fishes. True sturgeons appear in
451-823: Is smooth-skinned, scaleless, and armored with five lateral rows of bony plates called scutes . Several species can grow quite large, typically ranging 2–3.5 m (7–12 ft) in length. The largest sturgeon on record was a beluga female captured in the Volga Delta in 1827, measuring 7.2 m (23 ft 7 in) long and weighing 1,571 kg (3,463 lb). Most sturgeons are anadromous bottom-feeders , migrating upstream to spawn but spending most of their lives feeding in river deltas and estuaries . Some species inhabit freshwater environments exclusively, while others primarily inhabit marine environments near coastal areas, and are known to venture into open ocean. Several species of sturgeon are harvested for their roe , which
SECTION 10
#1732877105157492-557: The Baltic region are A. oxyrinchus , a species otherwise restricted to the Atlantic coast of North America. The wedge-shaped head of the European sea sturgeon ends in a long point. There are many sensitive barbels on the facial area. The dorsal fins are located very far back on the body. Five longitudinal lines of large osseous plates are found on the body of the fish. The stomach is yellow and
533-849: The Black , Azov , and Caspian Seas ( Danube , Dnepr , Volga , Ural and Don ); the north-flowing rivers of Russia that feed the Arctic Ocean ( Ob , Yenisei , Lena , Kolyma ); in the rivers of Central Asia ( Amu Darya and Syr Darya ) and Lake Baikal . In the Pacific Ocean, they are found in the Amur River along the Russian- Chinese border, on Sakhalin Island, and some rivers in northeast China. Throughout this extensive range, almost all species are highly threatened or vulnerable to extinction due to
574-485: The Early Jurassic period, some 174 to 201 million years ago. They are one of two living families of the Acipenseriformes alongside paddlefish (Polyodontidae). The family is grouped into four genera: Acipenser (which is paraphyletic , containing many distantly related sturgeon species), Huso , Scaphirhynchus , and Pseudoscaphirhynchus . Two species ( A. naccarii and A. dabryanus ) may be extinct in
615-776: The Gulf of Mexico to Newfoundland , including the Great Lakes and the St. Lawrence , Missouri , and Mississippi Rivers, as well as along the West Coast in major rivers from California and Idaho to British Columbia . They occur along the European Atlantic coast, including the Mediterranean basin, especially in the Adriatic Sea and the rivers of North Italy ; in the rivers that flow into
656-694: The La Hague site into the Alderney Race do not diminish significantly, it will be difficult to achieve the objective of zero radioelement concentrations in the North Atlantic by 2020. In June 2007, OSPAR signatory parties agreed to amend the Convention in order to make mandatory the application of the treaty in the case of geological storage of CO 2 . The treaty allows carbon capture and storage of carbonic anhydride from land to an offshore marine site through
697-515: The OSPAR Commission in 2019. [REDACTED] Sturgeon Sturgeon (from Old English styrġa ultimately from Proto-Indo-European * str̥(Hx)yón - ) is the common name for the 28 species of fish belonging to the family Acipenseridae . The earliest sturgeon fossils date to the Late Cretaceous , and are descended from other, earlier acipenseriform fish , which date back to
738-483: The cladogram , shows that they evolved from the bony fishes . Approximate dates are from Near et al. , 2012. Coelacanths , lungfish [REDACTED] Tetrapods [REDACTED] Polypteriformes ( bichirs , reedfishes ) [REDACTED] Acipenseridae [REDACTED] Polyodontidae [REDACTED] Lepisosteiformes ( gars ) [REDACTED] Amiiformes ( bowfins ) [REDACTED] Teleostei [REDACTED] In currently accepted taxonomy ,
779-552: The lake sturgeon ( Acipenser fulvescens ) and the Baikal sturgeon ( A. baerii baicalensis ), or have been forced into them by human or natural impoundment of their native rivers, as in the case of some subpopulations of white sturgeon ( A. transmontanus ) in the Columbia River and Siberian sturgeon ( A. baerii ) in the Ob basin. Sturgeons retain several primitive characteristics from
820-457: The Atlantic Ocean to the coasts of North America. Like many other sturgeons, they spawn in the rivers inland from the coast. The species can tolerate wide spread salinities and spend most of their lives in saltwater but migrate to spawn in freshwater. Until the first decades of the twentieth century, these fish were locally abundant in Europe and were caught extensively for their caviar , but
861-659: The European Community, Finland , France , Germany , Iceland , Ireland , the Netherlands , Norway , Portugal , Spain , Sweden and the United Kingdom of Great Britain and Northern Ireland ) and by Luxembourg and Switzerland . The OSPAR Convention entered into force on 25 March 1998, and replaced the Oslo and Paris Conventions, but decisions and other agreements adopted under those conventions remained applicable unless they are terminated by new measures adopted under
SECTION 20
#1732877105157902-447: The European sturgeon is a long process that might take 30-50 years. Bycatch in commercial trawls and gillnets, pollution, climate change, and potential competition with other species are dangers to the species. It was estimated there are 20 - 750 mature individuals in wild at the moment of assessment, which was at 2020. The European sea sturgeon faces various threats that have historically diminished population sizes and continue to impede
943-668: The OSPAR Convention. The first Ministerial Meeting of the OSPAR Commission at Sintra , Portugal, in 1998 adopted Annex V to the Convention, extending the cooperation of the signatory parties to cover "all human activities that might adversely affect the marine environment of the North East Atlantic" . Nevertheless, programmes and measures cannot be adopted under the Convention on questions relating to fisheries management, which are currently coordinated by European nations in
984-505: The back is a brownish grey. This sturgeon can reach 6 m (20 ft) and 400 kg (880 lb) in weight, but a more common length is 1.25 m (4 ft 1 in). They can reach an age of 100 years, and have a late sexual maturity (12 to 14 years for the males and 16 to 18 years for the females). They are found on the coasts of Europe, except in the northernmost regions and the Baltic region, and have rarely even been known to cross
1025-399: The bony fishes. Along with other members of the subclass Chondrostei , they are unique among bony fishes because their skeletons are almost entirely cartilaginous . To maintain structure, sturgeons are one of few organisms to retain a post-embryonic notochord that acts like a soft spine running through the body. Notably, however, the cartilaginous skeleton is not a primitive character, but
1066-443: The class Actinopterygii and the order Acipenseriformes are both clades . The family Acipenseridae is subdivided into 2 subfamilies; Acipenserinae , including the genera Acipenser and Huso , and Scaphirhynchinae , including the genera Scaphirhynchus and Pseudoscaphirhynchus . However, multiple recent studies have recovered this arrangement as paraphyletic , instead finding A. oxyrhinchus and A. sturio to form
1107-624: The convention is managed by the OSPAR Commission , which is made up of representatives of the Governments of the 15 signatory nations, and representatives of the European Commission , representing the European Union . The OSPAR Convention was concluded at Paris on 22 September 1992. It combines and up-dates the 1972 Oslo Convention on dumping waste at sea and the 1974 Paris Convention on land-based sources of marine pollution. The name
1148-454: The exact relationships of the members of the most derived , primarily Atlantic clade vary, although most analyses at least find all the species in it to form a monophyletic clade. The placement of A. sinensis also varies by the study, with some placing it as the only Pacific member of the otherwise Atlantic-based most-derived clade, whereas others place it with the rest of the Pacific sturgeons as
1189-510: The existence of a fossil record, full classification and phylogeny of the sturgeon species has been difficult to determine, in part due to the high individual and ontogenic variation, including geographical clines in certain features, such as rostrum shape, number of scutes, and body length. A further confounding factor is the peculiar ability of sturgeons to produce reproductively viable hybrids , even between species assigned to different genera . While ray-finned fishes (Actinopterygii) have
1230-455: The first releases in 1995. For example, 87 sturgeons were experimentally released in the Rhine river near Nijmegen in 2012 and 2015. Like other sturgeons, they eat polychaete worms and crustaceans which they find with their barbels. Although no specific population estimates are available, the abundance of wild, mature European Sturgeon is estimated to be less than 800 individuals. The last time
1271-511: The fossil record during the Upper Cretaceous , with amongst the oldest known remains being a partial skull from the Cenomanian (100–94 million years ago) of Alberta, Canada. In that time, sturgeons have undergone remarkably little morphological change, indicating their evolution has been exceptionally slow and earning them informal status as living fossils . This is explained in part by
European sea sturgeon - Misplaced Pages Continue
1312-409: The long generation interval, tolerance for wide ranges of temperature and salinity , lack of predators due to size and bony plated armor, or scutes, and the abundance of prey items in the benthic environment. They do, however, still share several primitive characteristics, such as heterocercal tail, reduced squamation, more fin rays than supporting bony elements, and unique jaw suspension. Despite
1353-1252: The most basal clade among sturgeons, and all other species being in a separate clade, with the various other species of Acipenser , Scaphirhynchus , Pseudoscaphirhynchus , and Huso to have varying levels of relationship with one another. A potential taxonomy of Acipenseridae is shown here, based on Luo et al . 2019, Nedoluzhko et al . 2020, and Shen et al. 2020. Note the paraphyletic relationships among genera: A. oxyrhinchus [REDACTED] A. sturio [REDACTED] A. dabryanus [REDACTED] A. schrenckii A. transmontanus [REDACTED] H. dauricus A. medirostris [REDACTED] A. mikadoi S. platorhynchus [REDACTED] S. suttkusi [REDACTED] S. albus [REDACTED] P. fedtschenkoi (likely extinct) [REDACTED] P. hermanni P. kaufmanni A. persicus A. stellatus [REDACTED] H. huso [REDACTED] A. ruthenus [REDACTED] A. nudiventris [REDACTED] A. fulvescens [REDACTED] A. brevirostrum [REDACTED] A. baerii A. sinensis A. gueldenstaedtii [REDACTED] The exact placement of Scaphirhynchus varies depending on
1394-573: The north east Atlantic and North Sea by the International Council for the Exploration of the Sea (ICES). The OSPAR convention now regulates European standards on marine biodiversity , eutrophication , the release of hazardous and radioactive substances into the seas, the offshore oil and gas industry and baseline monitoring of environmental conditions. In 2000, the OSPAR Commission published
1435-502: The paired fins of ray-finned fish is inside the body wall, although the ray-like structures in the webbing of the fins can be seen externally. OSPAR Convention The Convention for the Protection of the Marine Environment of the North-East Atlantic or OSPAR Convention is the current legislative instrument regulating international cooperation on environmental protection in the North-East Atlantic . Work carried out under
1476-409: The recovery of self-sustaining populations. Bycatch, primarily, has been a significant threat with the potential to counteract conservation efforts. Additionally, several other factors contribute to the challenges faced by this species. Bycatch emerges as the primary threat to European sea sturgeon populations, having played a crucial role in reducing their numbers in the past. This ongoing threat poses
1517-593: The species hatched was in the Garonne River in France in 1994, and genetic analysis reveals that the 1994 cohort was formed by only one mating pair. Because the wild population is so small, a captive breeding and stocking program is vital to the species' survival. Although restoration operations, such as artificially bred individual restocking, have been successful in the Gironde estuary and the Elbe River (Germany), recovery for
1558-512: The species in the Acipenser and Huso genera are monophyletic (descended from one ancestor) or paraphyletic (descended from many ancestors) is still unclear, though the morphologically motivated division between these two genera clearly is not supported by the genetic evidence. An effort is ongoing to resolve the taxonomic confusion using a continuing synthesis of systematic data and molecular techniques . The phylogeny of Acipenseridae, as in
1599-432: The species' long-term survival and recovery. Dam construction, pollution, and river regulation further exacerbate the challenges faced by the European sea sturgeon. These anthropogenic factors have led to the loss and degradation of crucial spawning and feeding sites. Additionally, the introduction of alien predators has been identified as a significant impact, hindering the recovery of sturgeon populations, as highlighted by
1640-404: The study and the methods used, with some placing it within the second-most basal clade comprising primarily Pacific species (shown above), whereas others place it in its own clade that is more derived than the secondmost basal clade but less derived than the most derived Atlantic and Central Asian clade. No studies have yet delineated a relationship between it and Pseudoscaphirhynchus . In addition,
1681-573: The wild , and one ( P. fedtschenkoi ) may be entirely extinct. Sturgeons are native to subtropical, temperate and sub-Arctic rivers, lakes and coastlines of Eurasia and North America . A Maastrichtian -age fossil found in Morocco shows that they also once lived in Africa . Sturgeons are long-lived, late-maturing fishes with distinctive characteristics, such as a heterocercal caudal fin similar to those of sharks , and an elongated, spindle-like body that