Sturgeon — Europe

“The water quality of the River Rhine has improved and might again suit the critically endangered European sturgeon A. sturio L, which was extirpated from the river by 1950. This study describes the tracking of 43 juvenile hatchery-reared A. sturio, in the Dutch part of the Lower Rhine and Delta . . . Redirection of the main flow of the River Rhine, imposed by the sea lock ‘Haringvlietdam’, led the sturgeons into the Rotterdam harbor . . . It is concluded that sustainable fisheries in the North Sea and cooperation with the fisheries sector is a critical prerequisite for a reintroduction program. Potential habitat improvements for rehabilitation of the European sturgeon in the River Rhine can be achieved by adapted management of the sea lock. Reconnecting the estuary to the North Sea will increase habitat availability in the transitional zone between fresh and saltwater (i.e. acclimatization area) and create more favorable estuarine conditions in the Delta.”

“Eighty-five percent of sturgeon, one of the oldest families of fishes in existence, valued around the world for their precious roe, are at risk of extinction, making them the most threatened group of animals on the IUCN Red List of Threatened Species. The latest update of the Red List assessed the status of 18 species of sturgeon from all over Europe and Asia and found that all were threatened. Twenty-seven species of sturgeon are on the IUCN Red List with 63 percent listed as Critically Endangered, the Red List’s highest category of threat. Four species are now possibly extinct . . . ’Sturgeon have survived dramatic change over the past 250 million years only to face the serious threat of becoming extinct as a direct result of human activities. Illegal catch, overfishing, the breaking up of the migratory routes and pollution are the key elements that have driven almost all species to the brink of extinction,’ says Dr Mohammad Pourkazemi, chair IUCN/SSC Sturgeon Specialist Group.”

“The nearly extinct European sturgeon, once so widespread it was known as the common sturgeon, has received a measure of protection that may help it survive. Meeting in Nairobi, Kenya, the Convention on Migratory Species, a United Nations agency, added it to a list of threatened wild animals, which means it can no longer be fished in the shallow waters of Europe’s coastlines, where it lives most of its life.”

“Following media coverage of an illegal capture and sale of an A. sturio in Les Sablesd’Olonne (France) in June 2004 the French Ministry of the Environment launched anadministrative inquiry which concluded that responsibility lay with the fisheries administration which had misinformed the fisherman . . . When a fisherman tried to sell a specimen illegally in Concarneau (France) in January 2007, he clashed with the director ofthe auction hall, who returned the fish to the water (and received official congratulations from the Fisheries Ministry, which can be considered as a positive consequenceof the awareness campaign among marine fishermen.)”

“European sturgeon (Acipenser sturio) is a critically endangered species, listed by the IUCN Red List 2010, CITES and Bern and Bonn conventions . . . Only from incidental catches in the 20th century it was deduced that the species was not extinct. Around 1990, two declining, relict populations were described in the Gironde-Garonne-Dordogne and the Rioni Rivers.”

“In general, protection was considered only after the stocks were reduced to an economically insignificant factor. The subsequent prohibition of catches throughout the range, their background and intentions were not communicated to the fisheries effectively. Therefore, despite the protection status, sturgeons were caught and sold without any consequences for the fishermen. Overall population sizes continued to decrease, and finally the species became extirpated in the 1970s to 1990s.”

“Until the World War II, sturgeon was an important source of income for fishermen of the Po River and its delta. A single large catch could provide sufficient revenue to maintain a family for a year. The meat was sold in the markets at Milan and other major cities, while the eggs were used to produce caviar. In Ferrara, a historically important town for fisheries and trade, located on the Po River just upstream the delta, a shop called ‘la Nuta’ sold a special type of cooked caviar until 1972, when it closed because sturgeon became very rare.”

“Sturgeon records from the Guadalquivir are available from the thirteenth century until 1992. From 1931 onwards, the spawning migration was interrupted by the building of the Alcala del Rio dam, causing a decline in all the migratory species. Ironically, a caviar and smoked-flesh factory started to run that same year . . . Additionally, human-induced aggressions such as the building of river dams and the establishment of gravel extraction factories combined with environmental phenomena such as dry springs, which restricted the spawning of sturgeon in the Guadalquivir, also had a negative impact on Iberian sturgeon. In retrospect, one can see that there were no chances of survival for the Guadalquivir sturgeon. The last specimen was caught in 1992 near the mouth of the river.”

“Spawning refuges were closed for the fishery in the Oste River (a tributary of the lower Elbe River) in 1898 until 1918. This measure was applied to 7 km of the river in an area where fertilized eggs had been detected (Quantz 1903) . . . The combination of various measures was also applied in later years. On the Eider River in 1915, a series of legal protection measures were effectuated to protect the sturgeon population and to support a sustainable harvest (Mohr 1915). These included: (a) the prohibition of baited hooklines using worms as bait, (b) increased intensity of surveys to prevent marketing of sublegal (<100 cm) sturgeons, (c) improving enforcement by increasing the number of fisheries officers for the Eider River, (d) increase of the legal size limit to 150 cm TL, and e) the attempt to buy fishing rights along the river to install protection areas. Point (d) was abolished again in 1916 (Ehrenbaum 1916), and the protected areas were not established until the dam at Nordfeld was completed in 1936, which blocked the migration of the adults to the spawning sites.”

“On average, a sturgeon fisherman caught 50–60 sturgeons per season which weighed up to 500 pounds. Between 1860 and 1890 the sturgeon meat was so cheap that even the farmers in the area (widely known not to waste money) served sturgeon meat at least once or twice a week”.

“During the first half of the nineteenth century, the sturgeons were so numerous in the southern Elbe River branch at the Köhlbrand stretch that it was impossible to make use of the catch. My grandfather and his employee caught 1,100 fish, and my father an additional 1,000 fish between April and August”

“At the turn of the eighteenth century, the European sturgeon was found to have an almost pan-European distribution . . . At the southern and northern edges of the distribution, isolated catches were reported along the Maghreb littoral (Heldt 1934; Furnestin et al. 1958), and single individuals were fished in the waters surrounding Iceland (Saemundsson 1949) and along the Norwegian coast (Collett 1875) as far as the Kola Peninsula (Lagunov and Konstantinov 1954).”

“We have some knowledge of the remote past situation in Portuguese rivers through the humanist André de Resende (1500-1573), whose posthumously published book De antiquitatibus Lusitaniae (1593) includes a chapter entirely devoted to the Portuguese rivers and the names of the sturgeon . . . Through Resende’s book (we know that the asturjão or soilho –the old Portuguese vernacular names of the sturgeon, which gave place, respectively, to the present ones esturjão and solho – was large and very good in the Minho, but small in the Lima. In the Douro it was less common than in the Minho, and it was very rare in the Tagus. Sturgeons of moderate size entered the Guadiana from March to the summer.”