Edinburgh Napier University

  Nutrient levels were monitored over a twelve month period in Bemersyde Moss, a shallow wetland in southern Scotland. The Moss is used by a variety of waterfowl, both as a winter roost by approximately 100-250 greylag geese (Anser anser) and in summer as a breeding colony for over 14,000 pairs of black-headed gulls (Laws ridibundus). It is surrounded by agricultural land, which along with the birds has an effect on nutrient levels. Phosphate phosphorus (PO4-P) and combined inorganic nitrogen (NH4-N, NO3-N and NO2-N) concentrations were analysed at fortnightly intervals, both in the drains flowing into the wetland and in the wetland itself. Abiotic parameters including pH, conductivity, temperature, depth, dissolved oxygen were also recorded. P and MH4-N showed high concentration in summer due to the influx of birds and use by livestock. Although some of the NO3-N could be attributed to the oxidation of NH4-N, increased levels in the spring and late autumn/early winter were measured in the field drains, suggesting an input from the surrounding arable fields. It was concluded that birds and livestock were making a major contribution to P and N levels within the wetland.