West Sutherland Elver Survey

West Sutherland Elver Survey 2008
1979 followed by a fall. Dekker (2003) estimated the decline in recruitment after the early
1980s to be up to 90% on a pan- European basis.
t/yr
80
70
60
50
40
30
20
10
0
1972
1974
1976
1978
1980
1982
1984
1986
Figure 6: Annual UK (England and Wales) catch of glass eel (tonnes) from Cefas Environment Agency and nett export
estimates between 1972 and 2005. It is assumed that > 95% is taken from the Severn Estuary. Effort has stayed same since
1980s.
STOCK DECLINE
The decline of the species has been reported by scientists since the 1940s in Northern
Europe, and since the 1980s in the rest of the continental range (fig. 5a). The scientists from
Indicang (pan European eel research group) have demonstrated that the European eel
stocks are in decline and in some regions, mainly in the North of its distribution area (rivers
of the North Sea, the Norwegian Sea and the Baltic Sea) the situation is critical (fig. 7).
Most scientists show that eel stocks have declined by a factor of ten during the past decade
(Moriarty and Dekker, 1997). Although some of restocking programs have succeeded in
sustaining local fisheries (e.g. Northern Ireland; Baltic Sea; and Italian lagoons), this general
decline is still continuing in all waters where significant stocking was not made and where
natural recruitment continues to decrease or, at the best, remains stable (Moriarty and
Dekker, 1997). Recent yellow/silver eel catches (CEFAS) in England and Wales were
estimated to be less than 5.0% of natural yields (Potter & Dare 2003).
PROBLEMS IDENTIFYING STOCK DECLINE
However there has been debate over whether a stock decline is occurring in some areas, as
some monitoring continue to show no change in stock despite elver fisheries (England:
Tweed, Severn and Dee). For example the River Severn Management Plan concluded that
there has been: 1) no change in eel distribution throughout the river, 2) no overall change in
1988
1990
1992
1994
1996
1998
Cefas/EA
Export
19 West Sutherland Fisheries Trust
2000
2002
2004