New report improves understanding of UK Shelf Seas ‘blue carbon’ role

6 November 2018

New report improves understanding of UK Shelf Seas ‘blue carbon’ role

The main outcomes from a five-year research programme on what is happening in the seas around Britain are published today.

The report covers top-down processes (how marine ecosystems are affected by the atmosphere) and bottom-up (the hidden benefits provided by the seafloor), as well as the impacts of human activities and climate change.

The UK Shelf Sea Biogeochemistry research programme was a £10.5 million study co-funded by the Natural Environment Research Council (NERC) and the Department for Environment, Food and Rural Affairs (Defra).  Results included a much-improved understanding of the role of shelf seas in removing and storing carbon (‘blue carbon’), and the lessons for policy in monitoring, managing and valuing these precious habitats. These findings provide evidence for Defra, the devolved administrations and other stakeholders to help ensure the sustainable use of the UK marine environment.

Key findings presented in the report include:

  • The UK shelf seas take up large amounts of carbon dioxide, thereby slowing global warming; however, many knowledge gaps remain
  • Climate change is already affecting UK shelf seas and impacts will intensify
  • Many interacting factors control the amount and growth of the microscopic plants (phytoplankton) that underpin nearly all other life in the sea
  • Surprisingly, a summer-time lack of iron may be one of the constraints on phytoplankton growth; this has not been found before in shelf seas
  • The chemistry and biology of shelf seas is strongly affected by the highly variable conditions at the seafloor, affected by natural processes and human disturbance
  • Marine protected areas provide unique opportunities for separating climate-driven changes from direct human actions; for example, trawling
  • Most trawling impacts on seafloor life and processes seem to occur the first time an area is trawled; on that basis, it would seem better to have high fishing effort in some areas and none in others, rather than equally spreading the seafloor disturbance
  • Novel technologies are increasingly being used to find out how shelf seas work, providing many direct and indirect benefits to society.

Dr Phil Williamson, the Science Coordinator of the UK Shelf Sea Biochemistry (SSB) programme said: “The seas around Britain are amongst the best-studied in the world.  Yet we are only just finding out how the many complex processes occurring there fit together.  Whilst this research programme was aimed at a better understanding of the big picture, the team also discovered many new facts on what is actually going on, and how our nearest part of the ocean might be vulnerable to future change”. 

Professor Stuart Rogers, Cefas Chief Scientist said: ‘This substantial programme identifies a range of policy implications that will be seized upon by managers and policy customers.  An appraisal of confidence in the key scientific findings, together with scientific uncertainties and knowledge gaps, provides necessary reassurance and signals a step forward in how we apply the results of high quality research’,

The SSB programme brought together more than 100 researchers from 15 universities and research centres, and involved more than ten research cruises on RRS Discovery and RV Cefas Endeavour, mostly in the Celtic Sea. The programme’s findings will help inform policy development in support of the sustainable use of the UK’s marine resources.


Shelf seas are regions of shallow water (less than 200m depth) between land and the open ocean. They comprise only around 7% of the global ocean, yet are arguably the most important part - providing human society with a wide range of extremely valuable ecosystem services. The shelf seas are highly productive compared to the open ocean, supporting more than 90% of global fisheries. Their importance to society also includes biodiversity, carbon cycling and storage, waste disposal, nutrient cycling, recreation and renewable energy resources. Consequently, the shelf seas have been estimated to be the most valuable biome on Earth. However, they are under considerable stress from human activities such as high nutrient inputs, overfishing, and habitat disturbance, as well as climate change and ocean acidification.

The synthesis report Shelf Seas: The Engine of Productivity is available to view here.