Note: Single-source report; awaiting corroboration.
Plastic pollution in the ocean continues to grow, driven by mismanaged waste, littering, microplastic abrasion, and marine activities. Estimates indicate about 52.1 million metric tonnes of plastic waste enter the marine environment annually. Regional differences show littering as the main source in the Global North, while uncollected waste dominates in the Global South.
This pollution harms marine life and habitats; more than 4,000 marine species are affected by plastics. The impacts extend to feeding, metabolism, immune function, growth, and reproduction, ultimately weakening and killing organisms and altering population dynamics, according to experts involved in the World Ocean Assessment.
Plastic debris includes large pieces that choke wildlife and disrupt habitats such as coral reefs before breaking down into microplastics and toxic substances. Visible floating and beach plastics represent only three to four percent of total ocean plastics, with much of the problem hidden below the surface, fragmented, or difficult to recover.
Microplastics, defined as plastic particles less than five millimetres long, exist from surface waters to the ocean’s deepest depths, with an estimated 24.4 trillion pieces in the upper oceans. They can cause changes to immune systems, inflammation, reduced growth rates, and energy imbalances in marine life. However, research on smaller particles such as nanoplastics and their long-term biological effects remains limited, complicating efforts to assess risks and manage pollution effectively.