Coregonus vandesius
Encyclopedia
Coregonus vandesius, the vendace, is a freshwater whitefish
found in the United Kingdom
. Population surveys of this species since the 1960s have revealed a steady decline.
, which is a more widespread North European freshwater whitefish species. Both taxa are also known by the common name
vendace. The status however remains controversial, and FishBase
still lists C. vandesius as a separate species, reflecting the recent treatment of the European freshwater fish fauna by Kottelat & Freyhof (2007). Another synonym of British C. vandesius is C. gracilior.
ic crustacean
s, such as copepod
s, as its primary food source. The fish does not migrate and has a life span of about six years. The species is now Britain's rarest fish.
and Derwent Water
in the English Lake District
, and the Castle Loch and Mill Loch in Lochmaben
, Scotland. The species is thought to have died out at all of these sites except Derwent Water. The Castle Loch population disappeared in the early part of the 20th Century, and the Mill Loch population disappeared in the 1990s. The fish has not been recorded at Bassenthwaite Lake since 2001. The declining populations of the fish are thought to be due to introduced species
that utilise the native vendace as a food source, and also due to pollution. For example, a water treatment works near the lake had been overflowing with raw sewage at times of high water levels, causing severe algae blooms which were depleting the lake's oxygen supply, but the plant was to be renovated in 2004 in order to prevent this.
Coregonus vandesius was introduced to Loch Skene in Dumfries and Galloway
, Scotland, in the 1990s as an attempt at ex-situ conservation
after the severity of habitat deterioration at Bassenthwaite was noticed. This has proved largely successful and Loch Skene now has nearly ten times more vendace per hectare than Derwent Water according to a survey carried out by the Centre for Ecology and Hydrology. Conservationists hope to reintroduce the fish to Bassenthwaite Lake once the habitat is restored.
Freshwater whitefish
The freshwater whitefish are fish of the subfamily Coregoninae in the salmon family Salmonidae. Along with the freshwater whitefish, the Salmonidae includes the freshwater and anadromous trout and salmon species as well as graylings...
found in the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
. Population surveys of this species since the 1960s have revealed a steady decline.
Taxonomy
Most authorities now consider Coregonus vandesius to be a subjective synonym of Coregonus albulaCoregonus albula
The vendace, Coregonus albula, is a species of freshwater whitefish in the family Salmonidae. It is also known as the European cisco. It is found in lakes in northern Europe, especially Finland, Sweden, Russia and Estonia, and in some lakes of the United Kingdom, northern Germany and Poland...
, which is a more widespread North European freshwater whitefish species. Both taxa are also known by the common name
Common name
A common name of a taxon or organism is a name in general use within a community; it is often contrasted with the scientific name for the same organism...
vendace. The status however remains controversial, and FishBase
FishBase
FishBase is a comprehensive database of information about fish species . It is the largest and most extensively accessed online database on adult finfish on the web...
still lists C. vandesius as a separate species, reflecting the recent treatment of the European freshwater fish fauna by Kottelat & Freyhof (2007). Another synonym of British C. vandesius is C. gracilior.
Biology
Coregonus vandesius inhabits deep, cold lakes, and uses planktonPlankton
Plankton are any drifting organisms that inhabit the pelagic zone of oceans, seas, or bodies of fresh water. That is, plankton are defined by their ecological niche rather than phylogenetic or taxonomic classification...
ic crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s, such as copepod
Copepod
Copepods are a group of small crustaceans found in the sea and nearly every freshwater habitat. Some species are planktonic , some are benthic , and some continental species may live in limno-terrestrial habitats and other wet terrestrial places, such as swamps, under leaf fall in wet forests,...
s, as its primary food source. The fish does not migrate and has a life span of about six years. The species is now Britain's rarest fish.
Distribution and habitat
The vendace has only ever been known as a native species at four sites in Britain: Bassenthwaite LakeBassenthwaite Lake
Bassenthwaite Lake is one of the largest water bodies in the English Lake District. It is long and narrow, approximately long and wide, but is also extremely shallow, with a maximum depth of about ....
and Derwent Water
Derwent Water
Derwentwater is one of the principal bodies of water in the Lake District National Park in north west England. It lies wholly within the Borough of Allerdale, in the county of Cumbria....
in the English Lake District
Lake District
The Lake District, also commonly known as The Lakes or Lakeland, is a mountainous region in North West England. A popular holiday destination, it is famous not only for its lakes and its mountains but also for its associations with the early 19th century poetry and writings of William Wordsworth...
, and the Castle Loch and Mill Loch in Lochmaben
Lochmaben
Lochmaben is a small town in Scotland, and site of a once-important castle. It lies four miles west of Lockerbie, in Dumfries and Galloway.-Notable people:*Angus Douglas - Scottish internationalist footballer...
, Scotland. The species is thought to have died out at all of these sites except Derwent Water. The Castle Loch population disappeared in the early part of the 20th Century, and the Mill Loch population disappeared in the 1990s. The fish has not been recorded at Bassenthwaite Lake since 2001. The declining populations of the fish are thought to be due to introduced species
Introduced species
An introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...
that utilise the native vendace as a food source, and also due to pollution. For example, a water treatment works near the lake had been overflowing with raw sewage at times of high water levels, causing severe algae blooms which were depleting the lake's oxygen supply, but the plant was to be renovated in 2004 in order to prevent this.
Coregonus vandesius was introduced to Loch Skene in Dumfries and Galloway
Dumfries and Galloway
Dumfries and Galloway is one of 32 unitary council areas of Scotland. It was one of the nine administrative 'regions' of mainland Scotland created in 1975 by the Local Government etc. Act 1973...
, Scotland, in the 1990s as an attempt at ex-situ conservation
Ex-situ conservation
Ex-situ conservation means literally, "off-site conservation". It is the process of protecting an endangered species of plant or animal outside of its natural habitat; for example, by removing part of the population from a threatened habitat and placing it in a new location, which may be a wild...
after the severity of habitat deterioration at Bassenthwaite was noticed. This has proved largely successful and Loch Skene now has nearly ten times more vendace per hectare than Derwent Water according to a survey carried out by the Centre for Ecology and Hydrology. Conservationists hope to reintroduce the fish to Bassenthwaite Lake once the habitat is restored.