Seagrass meadows around the British Isles are in “perilous state”

BBC News, 13th January 2016, reports: Most seagrass meadows around the coast of the British Isles are in a “perilous state”, say scientists. Plants are being damaged by pollution and human disturbances such as mooring boats, according to researchers.

Surveys of 11 sites in England, Wales and Ireland found high nitrogen levels in water were affecting the health of seagrass meadows at all but two areas.

In the 11 areas studied, even where conditions were good, seagrass faced damage from mooring or anchoring boats, said researchers Benjamin Jones and Richard Unsworth of Cardiff and Swansea universities. Dr Richard Unsworth of Swansea University said seagrasses were like the “canaries of the sea” in that their condition can be used as an indicator of the health of coastal waters.

Seagrass meadows are regarded as a valuable habitat on British shores, particularly as a nursery ground for fish.

“We conducted the most extensive assessment to date of the environmental conditions of seagrasses in the British Isles ” Dr. Unsworth told BBC News. “All the sites in our study were found to be at risk from either pollution, boating, or both, even those in relatively remote locations.”

He said the study showed action was needed to protect seagrasses in the British Isles. “We’ve historically lost at least 50% of these habitats in the British Isles, losing more should not be an option,” Dr Unsworth added.

Of the 11 sites monitored, the worst performing sites were three areas monitored in Wales and one of two sites in England, according to the research, published in the journal, Royal Society Open Science.

The sites were:

  • Skomer marine conservation zone around the Welsh island of Skomer
  • Gelliswick Bay, Pembrokeshire
  • Porthdinllaen in Snowdonia
  • Southend-on-Sea, England

Five other areas all had nitrogen levels higher than the global average:

  • Priory Bay, Isle of Wight
  • Ramsey Bay, Isle of Man
  • Langness, Isle of Man
  • Studland Bay, England
  • Kircubin Bay, Strangford Lough, Northern Ireland

However, two remote seagrass meadows around the Isles of Scilly and Mannin Bay off Connemara, Ireland — were relatively healthy.

Seagrass is a group of flowering plants that live in shallow sheltered areas along the UK coastline where they form dense green meadows under the sea. Because of where they grow they are vulnerable to damage from humans and are now a protected species.

The main plant in the UK is known scientifically as eelgrass, Zostera marina. It is the most widespread marine flowering plant in the Northern Hemisphere, inhabiting the cooler ocean waters of the North Atlantic and North Pacific.

It needs sunlight to grow, and is threatened by pollution and increased amounts of sediment in the water, which block sunlight and prevent seagrass growth. Seagrass beds are also affected by physical disturbances such as trampling, dredging, anchoring, and the use of mobile fishing gear on the sea bed.

Source: BBC News, 13th January 2016. For the full text, see

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