Quantification and characterisation of dissolved organic matter in the North Sea

Lead Research Organisation: University of East Anglia
Department Name: Environmental Sciences


This studentship aims to provide a strong training in pure and applied marine biogeochemistry focussing particularly on
dissolved organic matter (DOM) and the associated nutrients contained within it. The student will utilise state-of-the-art
analytical facilities alongside world leading sampling facilities developing skills in quantitative analysis, data interpretation,
problem solving and utilising this information to help develop evidence based policy for marine management.
Marine dissolved organic matter (DOM)represents a major and poorly understood component of the global carbon cycle. It
contains a very large range of compounds in terms of bioavailability and size. Concentrations are higher in coastal waters
and there is a net export to the open ocean which may constitute a globally significant short term carbon storage
mechanism. Coastal seas receive net external inputs of DOM from rivers and the atmosphere to augment material formed
in-situ via primary production and its resultant biological cycling. Our recent work has demonstrated the magnitude of this
carbon store and derived first order in-situ estimates of its rate of cycling. Such information is important for policy makers in
understanding and managing the role of shelf seas as carbon stores and for understanding how productivity is sustained in
temperate shelf seas after the spring bloom when available inorganic nutrient concentrations are severely depleted. Thus
an understanding of the DOM cycle is central to maintaining good environmental status a key component of UK and EU
environmental policy. NERC have just initiated a new cross institutional research programme (LOCATE) to study the transport and cycling of
organic carbon from terrestrial stores through to shelf seas. LOCATE will focus on three catchment draining major peat
deposits in Scotland, North Wales and SW England. The studentship proposed here will provide a direct contribution to
LOCATE from CEFAS and UEA focussing particularly on the very biogeochemically and hydrologically different UK east coast estuaries, along with studies of organic matter characterisation and degradation rates based on the unique CEFAS
smartbuoy mooring arrays in the North Sea. This studentship will therefore augment this major NERC initiative and also
further enhance the training environment for the student by nesting the work with a large and globally important large scale
research initiative and provide policy relevant information for CEFAS..
The student will join the ENVEast Doctoral training partnership receiving world class subject specific and transferable skill
training and a work within a large and successful DTP able to provide an effective, recruitment, management and
monitoring environment to support this experienced and broad ranging supervisory team. The student will be based within
the School of Environmental Sciences at UEA but with a supervisor within the School of Chemistry will also have access to
a wide range of facilities and expertise within that School which we anticipate will be particularly valuable in developing the
planned fluorimeteric characterisation work on the DOM. UEA and CEFAS have close and developing collaborative links
which exploit the academic and applied research to deliver world leading marine research focussed on the effective
management of the marine environment. The student will work closely with supervisors at CEFAS spending at least 3
months at Lowestoft over the course of the research time which will focus particularly (1) on operational monitoring in the
North Sea, particularly via the Smarbuoy system (including ship board working), (2) data interpretation in the context of the
wider CEFAS monitoring and modelling capability and (3) developing policy facing advice form the project.


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Description This project focusses on two main rivers of East Anglia, flowing into the North Sea. Furthermore, data collected from cruises in the southern North Sea with CEFAS will study the shelf sea. The River Yare and the River Waveney are part of the Broads National Park, area considered ecologically important, both for its wetland habitats and the biodiversity represented. This project aims at understanding the fate of dissolved organic matter (DOM) from rivers to the sea. DOM is composed by a vast array of compounds, different in size, availability and chemical composition. Rivers transport DOM, which mainly contains carbon, into the sea where it is exported, acting as a carbon store. It is poorly understood how much carbon it is exported from rivers to the sea and if it is transformed as it is transported downstream. Preliminary data show that carbon is transformed as it reaches the sea, probably transferring it back to the atmosphere by photobleaching or bacteria, before being exported to the sea. Furthermore, the use of spectroscopy and modelling allows to identify the chemical composition and the source of the carbon and nutrients coming from rivers.
Exploitation Route The information produced by this project could be used by policy makers to understand, acknowledge and manage shelf seas as carbone stores. Understanding the DOM cycle, which is an important but poorly understood component of the global carbon cycle, can also help in maintaining the good environmental status at the base of the UK policy. This project could also add information to the NERC LOCATE project with data collected from different UK east coast rivers and estuary, and data collected with CEFAS during seasonal cruises in the southern North Sea.
Sectors Agriculture, Food and Drink,Communities and Social Services/Policy,Education,Environment