25 September 2017
Cefas scientists in partnership with marine scientists across the UK have published extensive research following a large-scale health check on the UK's seabed.
The researchers looked into how industry and environmental change are affecting our seafloors and concluded more work must be done to safeguard these complex ecosystems and the benefits they provide.
As part of a large research consortium involving eight UK institutions and organisations, an intensive sampling campaign included three scientific cruises in just six months to examine areas of ocean located on the UK continental shelf. This helped scientists understand the sensitivity of these systems to human activities. The societal importance of these ecosystems extends beyond food production to include biodiversity, carbon cycling and storage, waste disposal, nutrient cycling, recreation and renewable energy.
The research findings are published today in a special issue of the journal Biogeochemistry.
Martin Solan, lead principal investigator and Professor in Marine Ecology at the University of Southampton, said: "Our seafloors are teaming with life, from microscopic organisms, to larger creatures such as fish and crabs. All interact as part of a complex system which plays a vital role in maintaining the health of the seabed and the rest of food web.
"Human intervention, such as fishing, pollution and activities causing climate change are all affecting these finely balanced ecosystems. Collectively, our research provides us with a new perspective on how the seafloor is being modified, for better or for worse, but more research is now needed to understand the longer-term consequences of such change for the wider environment and for society at large."
The research team has analysed the biodiversity, nutrient, metal and carbon cycling in areas of the seafloor around the UK subject to different environmental conditions and human use. Scientists at the Centre for Environment, Fisheries and Aquaculture Science (Cefas) used a combination of fieldwork and modelling to measure how pH (a measure of how acid or alkali a substance is) and organic carbon (carbon stored as organic material) changes across the seafloor.
During four research cruises to the north-west European continental shelf, Cefas scientists measured the concentration of pH across different types of seafloor sediment (such as mud, sand, sandy mud), both before and after the annual spring bloom in the Celtic Sea. The researchers found that the pH of the seafloor surface changes across these different sediments types, as well as seasonally because of changes in the plankton production in the water column. Briony Silburn, Biogeochemical Scientist at Cefas, said: "Observations of pH variability within a range of Shelf Sea sediments is really lacking. This study will provide a good starting baseline for pH upon which to measure changes driven by human impact or environmental change."
The oceans are an important sink for the atmospheric CO2 produced by humans (in activities such as burning fossil fuels). Scientists at Cefas used modelling techniques to estimate how much CO2 (in the form of organic carbon) is stored in the surface sediments of the seafloor across the North-West European continental shelf. These models found that the surface sediments could hold approximately 476 million metric tonnes of organic carbon, making these seabeds extremely important in regulating future climate change.
The research is part of a special issue of the scientific journal Biogeochemistry and includes contributions from the Centre for Environment, Fisheries and Aquaculture Science (Cefas), Scottish Association for Marine Science (SAMS), the University of Southampton, the National Oceanography Centre (NOC), University of Portsmouth, University of Oxford, Bangor University and Plymouth Marine Laboratory.
Dr Phil Williamson, from the University of East Anglia, who helped coordinate this research programme, said: "Much of what happens in the sea is out of sight and out of mind. This study has provided a wealth of insights into the natural recycling processes that are literally at the base of marine ecosystems, underpinning the many benefits that we obtain from the sea."
The Shelf Sea Biogeochemistry Special Issue can be found at: https://link.springer.com/journal/10533/135/1/page/1
The research was part of the Shelf Sea Biogeochemistry programme, investigating how natural and human processes interact in the seas around the UK.
Image: A Whelk taken using the Cefas SPI (Sediment Profile Imagery) camera deployed on-board the RRS Discovery