Plastic is the main source of litter on our beaches, according to an environmental group.
More than three million items of rubbish were discarded on our coastline at any one time, the survey by Keep Northern Ireland Beautiful estimated.
Plastic accounted for over 78% of the waste, including many single-use items such as drinks bottles and food wrappers.
Six of the top 10 most common littered items on beaches were derived from single-use plastics.
Environment Minister Edwin Poots said: "It is a reminder of our continued fight against plastic pollution and its devastating consequences."
In 2019, Keep Northern Ireland Beautiful marine litter surveyors recorded an average of 508 pieces of litter per 100 metres of beach. This equates to an estimated 3.3 million items on our coastline at any one time.
While plastic was the main problem, many short pieces of string and rope, which may have originated from fishing activity, were also found.
Surveys of beach litter are carried out four times a year by trained volunteers across 11 'reference' beaches around Northern Ireland's coast.
Every reference beach is cleaned within two weeks of the survey by a range of volunteers, including families and local groups to schools and businesses.
In 2019 nearly 600 volunteers got involved to help clean up the beaches, collecting over 540 bags of litter from the 11 reference beaches alone.
Praising volunteers, Mr Poots added: "This year's report highlights the steady progress being made in tackling marine litter in Northern Ireland, leading to a cleaner, greener place to live.
"The figures reveal the stark reality of litter on our beaches, with over 22,000 pieces of litter collected across 11 beaches, with 78% of this made from single use plastic."
He added: "We all want to see changes where we live and see a continuing reduction in the number of pieces of litter appearing in our waters and along our coastline. With summer upon us and an ease on coronavirus restrictions many of us may choose to holiday at home.
"However, I would remind people of the need to 'leave no trace', to take all their litter home with them and recycle it where they can.
"By adjusting our behaviours and acting responsibly we can all play our part in further driving down marine litter and making a day at the beach enjoyable for everyone, whilst also protecting our marine wildlife."
Jamie Miller, local environmental quality manager for Keep Northern Ireland Beautiful, said: "The vast majority of litter on our beaches comes from single-use plastics.
"Removing these items from beaches is a small step towards tackling a very large problem in our seas, which we are only just beginning to understand. "We all have a role to play in tackling this hugely concerning environmental issue and can start by making small positive changes to our behaviours, such as avoiding single use plastic where possible, and always putting our rubbish in a bin."
Mr Miller said the Covid-19 pandemic, which has seen people take extra steps to protect themselves, brings an extra challenge.
He added: "It is important that the public recognises that using Personal Protective Equipment comes with the responsibility of not just using it properly, but also disposing of it in a way that doesn't harm the environment and other members of the public."