​Nutrient pressures affecting the Island and in particular St Aubin's Bay are a long standing issue, clearly visible by the annual occurrence of the opportunistic seaweed - Ulva. A large volume of work has been undertaken to understand, monitor and regulate these pressures.  This work required consolidation to ensure that the appropriate monitoring/assessments are in place; to enable informed and evidence based decisions to be made regarding the Sewage Treatment Works (STW) replacement (in line with the regulatory road map) and prior to the implementation of catchment measures under the Water Management Plan.

This is a technical report that ties together historic and current work, assesses the robustness of aspects of the regulatory process for the STW; and reviews the current monitoring programmes and their effectiveness to measure nutrient reduction measures.

The key outcomes/ recommendations of this report will assist the department to direct its research/monitoring of the nutrient pressures affecting St Aubin's Bay in the most effective way.