Synoptic limnology of a diverse geological region: catchment and water chemistry

Abstract612 lakes in Northern Ireland between 1 and 100 hectares surface area were sampled in the summers of 1988–1990. Water analyses for major ions and nutrients are presented in summary form and demonstrate the wide range of lake chemistry in the region. Altitude was the main determinant of water chemistry, which varied from near rain water to greater than 100 mg Ca l−1 faithfully reflecting the underlying geology, even in regions of diverse geology. ‘Rainfall’ lakes were commonly depleted of potassium but enriched in calcium and bicarbonate compared to average rainfall composition in the area. Major ion chemistry in general plotted as expected on a diagram of Na/(Na + Ca) ratio against total dissolved solids, with major deviations only found in lakes on an offshore island or which were known to be polluted.Nutrient enrichment was widespread, 27% of lakes contained more than 100 µg TP l−1 enriched lakes were commonest in lowland areas but also occurred in upland lakes with afforested catchments.

[1]  R. Gibbs.  Mechanisms Controlling World Water Chemistry , 1970, Science.

[2]  J. Talling,et al.  The depletion of carbon dioxide from lake water by phytoplankton , 1976 .

[3]  C. Gibson.  An investigation into the effects of forestry plantations on the water quality of upland reservoirs in northern ireland , 1976 .

[4]  M. Small,et al.  A regional pH-alkalinity relationship , 1986 .

[5]  R. A. McCord,et al.  Characteristics of lakes in the eastern United States. Volume 3. Data compendium of site characteristics and chemical variables , 1986 .

[6]  A. Henriksen,et al.  Lake acidification in Norway - present and predicted chemical status , 1988 .

[7]  C. Jordan,et al.  The Variation in the Acidity of Ground and Surface Waters in Northern Ireland , 1990 .

[8]  M. Erlandsen,et al.  Regional and temporal variation in pH, alkalinity and carbon dioxide in Danish streams, related to soil type and land use , 1991 .

[9]  Steve J. Smith.  The Lakes of Northern Ireland: an annotated inventory , 1991 .

[10]  A. Henriksen.  The inapplicability of the Gibbs model of world water chemistry for dilute lakes , 1992 .

[11]  R. Harrison,et al.  Sulphur dynamics of forest ecosystems , 1992 .

[12]  Contributions to the regional limnology of Northern Ireland: the lakes of County Londonderry , 1992 .

[13]  A reply to the comment of Eilers et al.1 , 1992 .

[14]  C. Gibson,et al.  A comparison of sedimentary and diatom-inferred phosphorus profiles: implications for defining pre-disturbance nutrient conditions , 1993, Hydrobiologia.