Ponds, Pools and Lochans

2.2 The number of small waterbodies in Scotland


Scotland has many small waterbodies: over 150,000 in total, representing about half of the ponds and pools in the British countryside as a whole (Table 1).

Table 1.
The number of waterbodies in Scotland in 1990
Ponds, pools and lochans up to 2.0 ha 3 150,700
Lochs greater than 2.0 ha 4 4,500
From: Barr et al., 1994
 
Fortunately, some evidence suggests that, in recent years, Scotland has suffered less pond loss than England and Wales where the number of ponds has dropped by about 75% this century (PCG, 1994).

The National Amphibian Survey (Swan and Oldham, 1993) estimated loss rates of small waterbodies since 1950. It showed that in areas of Scotland for which information was available5 pond numbers declined in the agricultural centre and east of the country, increased in the southwest and declined slightly in the Highlands. These data should be treated with some caution however, particularly for the more remote parts of the country, where fewer surveyors were working. An increase in pond numbers is also reported from Central Scotland over the period 1860 - 1990 (Lassiere, 1992). However, this analysis was based on interpretation of 1:63,000 and 1:50,000 scale maps which do not show the majority of smaller ponds.

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Figure 3. There are at least 150,000 ponds and pools in Scotland, about half of the total in the British countryside. Pond Action

 

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Figure 4. Shortwood Common Pond (Surrey) is one of the richest ponds so far surveyed in Britain by Pond Action, with over 70 macroinvertebrate species in a single 3 minute hand-net sample and 58 wetland plant species. Pond Action


3 Assumes that 25% of ponds in the size range 1.0-5.0 ha in CS1990 were 2.0 ha or below. Sources: Barr et al., 1993; Barr et al., 1994.

4 Estimates of loch and reservoir numbers in Scotland were made by Smith and Lyle (1979). From counts of 1:250,000 scale maps they found 3788 water bodies of greater than about 4 ha (this was the smallest size water body they estimated was recorded on the 1:250,000 map). By extrapolation from 1:63,000 scale maps they estimated that there were a further 27672 water bodies less than 4 ha in Scotland (though no information was available about the lower size limit of waterbodies shown in the 1:63,000 scale map). Since OS 1:63,000 maps show ponds down to about 0.25 ha, this count seems largely consistent with the 1990 Countryside Survey data.

5 Dumfries and Galloway, Argyll and Bute, North, East and South Ayrshire, Renfrewshire and East Renfrewshire, North and South Lanarkshire, Falkirk, West Lothian, Midlothian, East Lothian, Fife, Moray and Aberdeenshire.

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