Vendace  (Coregonus albula)

This vendace is one of the UK's rarest freshwater fish (2); it is a small, streamlined (2) and slim fish with a bluish green back (5), a white belly (6) and silvery flanks (5). The fins are grey in colour becoming darker towards the margins (6). It has large eyes, a relatively small mouth and an adipose fin (5). Other common names for this species include 'whitefish' and 'European cisco' in England and 'Fendas' in Welsh (7).

Found in north-west Europe between the English Lake District in the east to western Russia, and from a northern extreme in Scandinavia to north western Russia reaching south to Bavaria (2). Historically this species has been recorded from just four UK lakes; two in Scotland (3), and two in the English Lake District (8). One of the Scottish populations has not been recorded since 1911 when a sewage works was built; the other Scottish population has not been recorded since the 1970s (9) and so the species is classed as extinct in Scotland (10).

Occurs in open water shoals in deep, cold lakes where the species can take refuge from hot summer temperatures (2) (6). It also requires shallow areas with a gravely substrate for spawning (7).

In Britain the vendace occurs only as non-migratory freshwater populations, but in the Baltic it occurs as anadromous populations (they spend most of their time in saltwater and migrate to freshwater to spawn) (7). The vendace feeds primarily on free-swimming organisms such as water fleas (6) and planktonic crustaceans (5).

Spawning occurs in November and December (6); adults move to the edges of lakes, and females scatter the small two millimetre diameter yellow to orange eggs in gravely areas in still water (6). The eggs are fertilised externally and develop slowly on the bottom of the lake (7), hatching the following spring (2). Individuals are thought to live up to six years of age (2).

The vendace has faced pressure from the introduction of non-indigenous fish species, which were probably introduced by pike anglers using live bait (2). Juvenile roach compete for planktonic food with vendace, and ruffe eat vendace eggs (2). Ruffe were recorded in Derwent Water for the first time in 2001 (11). Other threats are habitat loss and pollution, particularly eutrophication resulting from nutrient enrichment (3), and siltation of spawning sites with organic matter (9). The A66 passes close to Bassenthwaite Lake; an accident involving an industrial tanker would be devastating (2).

The vendace is fully protected under the Wildlife and Countryside Act (1981), and both lakes are Sites of Special Scientific Interest (SSSIs) and candidate Special Areas of Conservation (2). Bassenthwaite Lake is also a National Nature Reserve managed by the National Trust. The management plan for this site takes into account the presence of vendace (3). A current conservation measure involves hatching vendace eggs from Bassenthwaite Lake in captivity and releasing the young back into the lake (11). In addition, young vendace from Bassenthwaite and Derwent Water have been released into two Scottish water bodies. A survey of water bodies in Cumbria aimed to detect suitable places for the establishment of refuge populations, however no suitable sites were found (11).

The vendace is a priority species under the UK Biodiversity Action Plan (UK BAP); the Species Action Plan aims to maintain the current populations and re-introduce the species to Scotland by 2005 (3).

For more on the vendace see:

• Cumbria Biodiversity Action Plan: Vendace:
  www.wildlifeincumbria.org.uk/cbap/index.asp
• Winfield, I.J., Fletcher, J.M. and James, J.B. (2004) Conservation ecology of the vendace (Coregonus albula) in Bassenthwaite Lake and Derwent Water, U.K. Annales Zoologici Fennici, 41: 155-164. Available at:
  http://www.sekj.org/PDF/anz41-free/anz41-155.pdf

Information authenticated by the Environment Agency:
http://www.environment-agency.gov.uk/