Plastic pollution in the Can Tho River, Vietnam

Plastic pollution in aquatic systems has emerged as a critical environmental issue, posing major threats to biodiversity and human health, and causing substantial economic losses. A deeper understanding of this issue is essential for developing effective strategies to reduce plastic waste. This study, conducted in collaboration with the non-profit organization The Ocean Cleanup, investigated the composition and sources of floating debris in the Can Tho River, a tributary of the heavily polluted Mekong River in Southeast Asia. The Ocean Cleanup, based in the Netherlands, addresses plastic pollution using innovative technologies to extract plastic waste from some of the world's most polluted oceans and rivers. Among these technologies are “Interceptors,” which use floating barriers to capture debris in polluted waterways. The research focuses on macro debris, items measuring 5–50 cm, that were intercepted during a six-week fieldwork period from September 23 to November 6, 2024, at Interceptor 003 in the Can Tho River, Vietnam. A standardized protocol, based on international guidelines, was applied to ensure consistency and detailed analysis. The study involved an examination of the composition of the intercepted debris and conducted an in-depth analysis of 342 sampled items, which were identified as human-made (anthropogenic). The items were classified and analyzed based on various factors, including size, weight, origin, production company, brand, production and expiry dates, degradation state, and polymer type. In total, 1592.4 kg of debris (wet weight) was intercepted, with 1464.9 kg (92%) classified as Organic/Residue. Of the anthropogenic macro debris (5–50 cm), plastics represented the largest share by weight, accounting for 115.6 kg (7.3%). The most common plastic types by item count were Hard plastics, Soft plastics, and Foam plastics, each comprising 80 items (23%). Notably, PET Drink bottles emerged as the most frequent individual plastic item, with 52 pieces (15.2%), followed by Plastic Bags and Foam Fragment < 50 cm, each contributing 39 items (11.7%). Within the Organic/Residue category, a 20 kg subsample contained 153 smaller meso items (0.5–5 cm) weighing a combined total of 160 g. An analysis of the origins of debris in the Can Tho River revealed that 85 items (85.7%) originated from Vietnam, and were primarily produced by local companies under national brands. The production dates indicated that 34 items (77.3%) had been manufactured within the past year. Additionally, degradation assessments showed that 141 items (41.2%) exhibited moderate degradation, suggesting a recent influx of debris into the aquatic environment. These findings emphasize the localized and recent nature of plastic pollution in the Can Tho River and highlight the urgent need for targeted waste management strategies, particularly in riverside areas, to mitigate the entry of plastic debris into aquatic systems.