Canaries of the sea’ under threat

Scientists at Swansea and Cardiff universities have found seagrass meadows around the coast of the British Isles to be in a “perilous state”.

Dr Richard Unsworth from Swansea University, who conducted the research with Benjamin Jones from Cardiff University, said: “We conducted the most extensive assessment to date of the environmental conditions of seagrasses in the British Isles, using techniques widely used to assess these important habitats in places such as the Great Barrier Reef. 

“ Seagrasses are the “canaries of the sea”, due to their sensitivity to a changing environment: like the canary in the coal mine their condition can be used as an indicator of the condition of our coastal seas.

“ We’ve historically lost at least 50% of these habitats in the British Isles. All the sites in our study were found to be at risk from either pollution, boating, or both, even those in relatively remote locations.”

“We are consistently seeing smaller, less productive seagrass plants in places where water quality is low. This ultimately creates less habitat and less affable conditions for associated animal life. Seagrass in the British Isles was found to be subjected to 75% (on average) more nitrogen than similar seagrass globally.


“ Seagrasses are so important for juvenile fish such as Cod, Plaice, Pollack and Whiting and are the preserves of many other fish species including the Spiny Seahorse Hippocampus guttulatus.  Losing our remaining seagrass is not an option if we want to support our fisheries. 

“ Our study shows how we need to take action to protect our seagrasses in the British Isles.

To make seagrass more resilient in the future so that they can support our fragile fisheries, we need to improve water quality in our coastal seas and reduce disturbance from boating activities in and around these sensitive habitats.”

The research conducted by Benjamin Jones (Cardiff University) and Richard Unsworth (Swansea University) helped inspire their development of the rapidly growing seagrass education and conservation charity Project Seagrass . Project Seagrass have recently launched a website (and have an app in development) to encourage members of the public to report sightings and information about the location and condition of seagrass in their area . They also have an ongoing campaign titled “For cod sake save seagrass”.