Plastic bottles a top coastal concern

Plastic bottles and jellyfish emerged as a cause of concern in the latest All-Ireland Coastwatch survey.

The total plastic bottle count by Coastwatch volunteers, at 14,747, was the highest ever for 15 years, according to international co-ordinator Karin Dubsky.

Ms Dubsky, a marine ecologist working at Trinity College Dublin, said plastic bottle litter, at around 60 per km of shoreline, highlighted the need for bottle deposits to stop littering.

Jellyfish were found to be more common than in any previous Coastwatch survey, according to the results of 498 survey sites of 500m in length.

Just before the survey began last September, a lion mane jellyfish, measuring just over 1.5m in diameter, was found on the west coast.

The jellyfish, also known as hair jelly, is the largest species of jellyfish.

“What is more remarkable is the huge numbers of jellyfish,” said Ms Dubsky. “In some areas, the jellyfish killed salmon in their cages, particularly in the Galway Bay area.”

The survey, launched yesterday by Environment Minister Phil Hogan, found that, generally, the west coast was cleaner than the south and east coast.

“There were no red areas on the west coast except for an inlet in Tralee Bay [Co Kerry] where the sea funnelled litter together,” said Ms Dubsky.

The Coastwatch team at TCD found that stream, drain, and piped discharge quality had improved along the shoreline. However, eight of the 414 inflows carried oil and 14 sewage or sewage fungus.

The number one threat to the shore was erosion, followed by water pollution and recreational abuse.

Ms Dubsky said the long, hot summer might have increased recreational threat records.

Coastwatch volunteers were find to discover even more honeycomb worm reefs on even more sites — they were found in counties Wexford, Waterford, Kerry, Galway, Sligo, and Donegal.

“Nobody gets excited about them until they find one,” she said. “They are incredibly complex creations with millions of worms getting together, working like an orchestra and creating a marvellous structure.”

The biogenic reef creations, which indicate that the area’s environmental status is good, are made of sand and body glue produced by pink little worms.

However, Coastwatch volunteers were disappointed when they found the Pacific oyster growing on rocks in Galway Bay. Also known as the Japanese or Gigas oyster, it is an invasive alien species.

The oysters were introduced through aqua culture and have become a problem where they have escaped from their cages.

“They can turn a shore into something you cannot even walk on because the shells are like knives and they can cut through your feet,” said Ms Dubsky.

Erosion remains a number one problem and Coastwatch want the Foreshore Act to include a national erosion policy.