Objectives
The primary benefit of this work will be to support Defra and UK regulatory decisions and inform policy development in relation to the transport of contaminants. In addition, understanding of contaminant, nutrient and sediment dynamics and fisheries recruitment is central to Defra's responsibility for health of the marine environment and requirement to ensure sustainable fisheries. The work supports the UK input to ICES, the Oslo and Paris Commission (OSPAR) and Ministerial North Sea Conferences and will assist with implementation of the EC Nitrate Directive contribute to the Marine Monitoring and Management Group.
It has been argued by a number of contracting parties to OSPAR that phytoplankton production in the vicinity of the Dogger Bank and European coast is fuelled by UK coastal inputs. It is inferred that eutrophication processes occur in the North Sea and that the UK's estuaries and coastal waters contain large concentrations of nutrient inputs from anthropogenic sources. The contention is that these inputs are contributing to eutrophication in UK coastal waters, offshore waters and other member states 'sensitive' coastal waters. However, uncertainties over pathways is hampering a satisfactory resolution. It is intended that in future improved knowledge of circulation will help inform the extent to which monitoring programmes (e.g. NMMP) relate to regions as a whole.
Similar concerns exist for the Celtic Seas, where knowledge of pathways is even more uncertain. The OSPAR QSR 2000 for the Celtic Seas identifies a fundamental lack of understanding concerning climate and changes in physical hydrography and how this might influence water movement and biological production. There is also a lack of understanding of the role that fronts play in contaminant and sediment movement and the abundance of fish, fish eggs and larvae. Knowledge of this will resolve questions relating to harmful algal blooms, nutrients and biodiversity.
In addition to observational methods, the project encompasses 3D baroclinic (density-driven) modelling to aid understanding of the physical processes. Forced by tides, winds, heating and freshwater input, the modelling (developed from the Princeton Ocean Model) is used to predict transport and dispersal, in particular of sediment, fish eggs and larvae and contaminants. Observations of jet-like pathways provide an important test for shelf seas models, which have yet to adequately reproduce such flows.
Increasingly, it is being recognised that 'Smart' technology (SmartBuoys) has an important role to play in monitoring and managing the health of the shelf seas. To maximise the potential of this approach the inevitably limited instrumentation must be deployed at strategic locations, taking full account of prevailing pathways. The work proposed here will inform the choice of locations, which necessarily need to be maintained if the value of the information is to be realised.
Climate change is of increasing concern and has the potential to significantly alter pathways and in remobilisation of contaminants through the modification of the seasonal heating cycle to which the circulations are linked. Significant climate change and inter-annual variability are likely to disrupt the present balance between tidal mixing and solar heating, either strengthening and increasing the duration of circulation or weakening and decreasing the length, potentially altering pathways.
