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Water and soft drink bottles made from polyethylene terephthalate (PET) sink at sea unless they contain trapped air, whereas their lids are made from polymers that float and can drift long distances. We sampled loose lids and bottles at 21 South African beaches to compare their origins. The proportions of foreign-made bottles and lids were correlated, and increased away from urban centres, indicating that much land-based litter strands close to source areas. Over 80 % of foreign-made drink bottles and 90 % of lids came from Asia, but most bottles were manufactured in China, Malaysia-Singapore and the UAE, and were dumped from ships. By comparison, most loose lids were in poor condition after being carried across the Indian Ocean from Indonesia by the South Equatorial Current. Reducing PET drink bottles at sea requires enforcement of regulations banning dumping at sea, whereas reducing their lids requires better control of littering in source countries., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Recent studies using bottles as tracers have shown that illegal dumping from ships is responsible for the rapid increase in drink bottles washing up on oceanic islands and at remote continental beaches away from local litter inputs. However, these studies have been in areas with moderate to high levels of shipping activity. I examined bottles stranded on the Pitcairn Islands in the central South Pacific, which are far from major shipping routes. Drink bottles from Asia dominated, with most coming from China. The top four brands (three Chinese and one multinational) were the same as at Tristan da Cunha in the central South Atlantic Ocean, which lies on the shipping route between South America and Asia. Bottle ages also were similar at Pitcairn and Tristan, indicating that vessels are the main source of bottles at both islands. Stricter controls are needed to reduce illegal dumping of plastics at sea., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Identifying the source of marine litter is essential to design effective mitigation measures to reduce plastic leakage into marine ecosystems. Kenya recently banned the use of polyethylene bags, but PET drink bottles remain a contentious source of litter in the country. I collected bottles and other single-use containers at nine Kenyan beaches, and compared their composition, country of manufacture and approximate age (time since manufacture) to bottles collected in coastal towns. Locally manufactured bottles dominated street litter (98%) and on urban beaches (93%) but became increasingly uncommon with distance from coastal towns, comprising only 30% of bottles at remote beaches. These steep spatial gradients indicate that most local bottles do not disperse far from source areas. The presence of lids is important for long-distance dispersal of glass and PET bottles, and many PET bottles littered in urban areas lack lids. HDPE bottles are much more common on beaches than on streets, and most come from Indonesia. The presence of epibionts and bite marks suggest that most HDPE bottles have drifted in the South Equatorial Current from southeast Asia, whereas foreign PP bottles mostly come from Indian Ocean island states. Reducing plastic leakage in southeast Asia should reduce the amount of beach litter throughout the western Indian Ocean. Some foreign PET bottles come from neighbouring states, but many are probably dumped illegally from ships operating from Asia. In addition to reducing plastic leakage from land-based sources, we need to ensure compliance with MARPOL Annex V regulations banning the disposal of plastic wastes at sea., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Most plastic debris floating at sea is thought to come from land-based sources, but there is little direct evidence to support this assumption. Since 1984, stranded debris has been recorded along the west coast of Inaccessible Island, a remote, uninhabited island in the central South Atlantic Ocean that has a very high macrodebris load (∼5 kg·m -1 ). Plastic drink bottles show the fastest growth rate, increasing at 15% per year compared with 7% per year for other debris types. In 2018, we examined 2,580 plastic bottles and other containers (one-third of all debris items) that had accumulated on the coast, and a further 174 bottles that washed ashore during regular monitoring over the course of 72 d (equivalent to 800 bottles·km -1 ·y -1 ). The oldest container was a high-density polyethylene canister made in 1971, but most were polyethylene terephthalate drink bottles of recent manufacture. Of the bottles that washed up during our survey, 90% were date-stamped within 2 y of stranding. In the 1980s, two-thirds of bottles derived from South America, carried 3,000 km by the west wind drift. By 2009, Asia had surpassed South America as the major source of bottles, and by 2018, Asian bottles comprised 73% of accumulated and 83% of newly arrived bottles, with most made in China. The rapid growth in Asian debris, mainly from China, coupled with the recent manufacture of these items, indicates that ships are responsible for most of the bottles floating in the central South Atlantic Ocean, in contravention of International Convention for the Prevention of Pollution from Ships regulations., Competing Interests: The authors declare no conflict of interest.