Northern Ireland's beaches were the most littered in the UK last year, a survey showed.
The amount of rubbish per kilometre of sand, 8,224 items, represented an increase of more than 60% compared to 2011.
Glass pieces made up almost 14% of all refuse found during a weekend last September, according to the Marine Conservation Society (MCS).
Rising volumes of crisp, sweet, lolly and sandwich wrappers abandoned showed decades of anti-litter campaigning were not having an effect and needed to be reinvigorated for a new generation, the MCS report added.
Dr Robert Keirle, MCS pollution programme manager, said: "As we continue to embrace the concept of a throwaway society it's no surprise that plastic dominates the litter we find.
"In Northern Ireland we have also seen a rise in the amount of cigarette stubs on beaches, possibly pointing to the fact that the smoking ban has forced smokers outside to dispose of stubs on the floor rather than in an ashtray."
During MCS Beachwatch Big Weekend 2012 in Northern Ireland in September, 157 volunteers cleaned nine beaches, covering a total of 1.38 kilometres.
In total, 11,308 items of litter were collected, filling more than 103 bags. For every kilometre surveyed, 8,224 pieces of litter were picked up.
The litter density in Northern Ireland represented an increase of more than 60% compared to Beachwatch Big Weekend 2011 (4,948.5 items/km) and was greater than Wales, Scotland or England.
Dr Keirle added: "Despite last summer being seen as a wash-out by many with heavy rain in many places, it appears those people that did visit our beaches left behind a lot of personal litter - sweet wrappers, ice cream wrappers and plastic drinks bottles failed to find their way into rubbish bins and ended up being dropped and left behind.
"This year's figures point to people becoming less bothered about littering."