Illegal dumping, coastal erosion and the killing of marine animals are among the concerns highlighted in the latest All Ireland Coastwatch Survey.
The results, released on Monday, showed that on the 300 km of Irish coast surveyed by Coastwatch this year, some 14,000 discarded plastic bottles were recorded, along with 5,726 metal drinks cans.
Plastic bottles and metal drinks cans appeared in 83 per cent and 68 per cent of survey areas respectively, with plastic bags observed in nearly half of all areas.
The survey also said that wetland and sea areas in Youghal in Co Cork and Bray in Co Wicklow have received more waste due to the encroachment of nearby landfill sites.
Tyres were found along 23 per cent of coastline and now comprise the most widespread large litter type along Ireland’s shores.
‘Seafloor damage’
Researchers also noted that there are "unlicensed" aquaculture installations along approximately 15 km of the Donegal shore, which are causing "visible seafloor damage".
The survey said that the effects of dredging in Carlingford Lough can now be seen on satellite images from space, in an area that is home to a threatened species of oyster.
As well as damaging habitats, the survey found that humans have also been responsible for killing sea creatures .
Six seals were found dead, one of which was believed to have been shot, in addition to the 100 live seals recorded across 37 locations.
Two headless leatherback turtles were also found in Co Cork and Co Wexford.
Erosion
The survey said that some older sand dunes continue to erode at an alarming rate, such as those in Portrane in Co Dublin.
Sand mining activity was witnessed at dunes in Baile an Reannaigh in Co Kerry.
More than 200 discharge inflows were tested for nitrates along various parts of the Irish coastline, of which 24 breached the legal limit of 50 mg of nitrate per litre of water, which represented a higher rate of contamination than in previous surveys.
While 68 per cent of survey sites were rarely or never affected by sewage, discoloured scum or froth was reported in about 12 per cent of areas covered, with bad smells noted along 7 per cent.
The results for 2015 were collated from 552 surveys sent in by more than 1,000 Coastwatch volunteers across the island.
Cleanups were also initiated at particularly polluted sites.
Summary
Portrane - Large dune complex reported as being “badly eroded”, and new dune sites are now developing in the south of Dublin Bay.
Carlingford Lough - Mussel dredging has resulted in impacts to the lough bed that are visible from space.
Dublin Bay - Invasive species of Spartina grass recorded for the first time in the bay.
Bray - Old closed dump near the town continues to fall into the sea, with waste-related contamination also an issue at wetland in Youghal.