Close to 30,000 volunteers cleared more than 100,000 kilograms of trash from 5,000 kilometres of Canada's coastlines in a massive one-day effort last year -- and the dirty details of what was collected are now in.

The Canadian contribution was part of a global initiative that saw more than 378,000 volunteers in 76 countries join the Ocean Conservancy's International Coastal Cleanup. They cleared more than seven million items of trash from coastlines around the world.

Now the conservation group has released a shocking report documenting the items that were collected worldwide last September, along with its grim conclusion: the ocean is hurting.

"Fundamentally, the ocean is the life support system for our planet," wrote Vikki Spruill, president and CEO of the Ocean Conservancy, in the report.

"Harmful impacts to that support system, such as marine debris, global warming, over fishing, pollutants, and habitat destruction, are exacting a toll we can no longer afford to pay. The plain truth is that our ocean cannot protect us unless it is healthy and resilient. And sadly, our ocean is sick."

Volunteers covered 50,000 kilometres of shoreline on the cleanup day last year, in areas ranging from Oregon to Mozambique and Canada's coasts.

The top 10 items found on the world's anything-but-pristine beaches and coasts, and their percentage of the total trash haul, are listed below:

The vast majority of the items collected fit within the Top 10 list, accounting for 84.1 per cent of the total.

Volunteers also found 81 birds, 30 mammals, 11 reptiles and one amphibian entangled in debris during the cleanup, according to the report.

Discarded fishing gear, including crab, lobster and fish traps, to fishing line, nets and rope also made up a good portion of the total -- with 247,099 items collected.

On average, volunteers collected 90 kilograms for every two-kilometre stretch of coast.

In the U.S. alone, 190,000 volunteers in 45 states combed 20,000 kilometres of coast, or about a third of the world-wide total, and collected two million kilograms of trash.

But the Ocean Conservancy believes the efforts amount to more than just cleaner shorelines.

"In addition to cleaner beaches and less polluted water, their efforts also provide vital information to help us understand the activities that produce debris and help prevent it in the first place," Spruill said.

Perhaps not surprisingly, it seems as though a high percentage of the trash found by volunteers was the result of simple carelessness by beach-goers, with 1.7 million food wrappers, containers, lids, cups, plates, utensils, and 1.2 million plastic bottles and beverage cans collected.

The report from the Ocean Conservancy also listed a number of ways people can make a difference, from joining the annual coastal cleanup, to reducing your footprint, switching to organic household cleaners and reusable items such as plates and cups.

The group has been holding the cleanup since 1986.