A PRELIMINARY-STUDY OF THE RELATIVE IMPORTANCE OF RIVERINE NUTRIENT INPUTS TO THE SCOTTISH NORTH-SEA COASTAL ZONE

A major study is presently underway studying physical and chemical processes in the coastal strip extending out to the 50 m isobath bordering the east coast of Scotland from the Moray Firth in the north to the Firth of Forth in the south; the Scottish North Sea Coastal Zone (SNSCZ). As a preliminary study the mean seasonal discharges and concentrations of nutrients (nitrate, ortho-phosphate and silicate) are tabulated for rivers flowing into the SNSCZ. From these data annual and seasonal fluxes of nutrient to the Coastal Zone are calculated. While estuarine processes may modify nutrient flows into the SNSCZ the calculations presented here allow an order of magnitude comparison of maximum riverine nutrient inputs with those from atmospheric and advective sources. By employing conceptual models of coastal zone circulation, it is demonstrated that fluxes of nitrate and phosphate to the SNSCZ are likely to be dominated by those due to advective cross-isobath transport from offshore. Riverine inputs of nutrients may however be important locally. Results from these analyses are presently being used to direct process studies in the SNSCZ.