Scotland's Wildlife – an assessment of biodiversity in 20

Table 7.4
Status of freshwater & wetland priority species in 2005 and in 2008
Source: Biodiversity Action Reporting System
Fresh water & wetland species 2005 2008
Assessed in either year count % count %
Not a true species
Trend unknown 10 31 4 13
Lost (pre BAP publication)
Lost (since BAP publication)
Declining (continuing/accelerating) 4 13 4 13
Declining (slowing) 3 9 3 9
Fluctuating - probably declining 1 3 1 3
No clear trend 4 13 7 22
Fluctuating - probably stable 1 3 4 13
Stable 6 19 6 19
Fluctuating - probably increasing 1 3
Increasing 3 9 2 6
7.4 Wildlife indicators
Environmental improvements have reduced air, land and water pollution, allowing
wildlife to re-colonise parts of Scotland that had become degraded by industrialisation
and dereliction. Fish diversity is being restored in the catchments and estuaries of the
Forth and Clyde. Otter occupancy rose from 57% of Scotland in 1979 to 92% in 2004
(S12 – Otter Indicator).
Similarly, the indicator of macroinvertebrate diversity increased between 1981 and 2008
(S13 – Freshwater Macroinvertebrate Diversity Indicator), but earlier data reflect
targeted sampling of polluted sites, skewing the sample towards stretches of river with
relatively low invertebrate diversity. The indicator is being looked at to consider how an
update might provide a more accurate representation of the condition of invertebrate
assemblages in general.
Wintering waterbird numbers (38 species) peaked at 120% in 1996/97 and remained
relatively stable prior to declining in recent winters up to 2006/07 (S4 – Abundance of
Wintering Waterbirds Indicator). The recent decline may suggest that waterbirds are
becoming less reliant on the security of overwintering in Scotland, and therefore less
abundant, as mild winters become commoner on continental Europe. Nevertheless, in
2006/07 the indicator was 107% of the 1975/76 baseline value. Goose numbers (6
species) increased to 311% in the winter of 2003/04, before falling back to 294% in
2006/07; wildfowl numbers (15 species) have remained relatively stable at 99% in
2006/07; wader numbers (13 species) peaked at 109% in 1996/97 but then declined to
78% in 2006/07.
49