High PM_2.5 Emission from Typical Old, Small Fishing Vessels in China

Old, small fishing vessels (OSFVs) account for a considerable proportion of the fishing fleet in China, the world’s top fishery country. Exhaust from OSFVs is often poorly controlled, but because of a lack of measurements, the magnitudes of OSFVs’ emissions in China remain unclear. In this study, we measured real-world PM_2.5 emission factors (EFs) from three typical OSFVs, together with other commonly used offshore vessels, in Hainan, China. The average PM_2.5 EF for OSFVs is 71.7 (37.3–92.7) g·(kg fuel)⁻¹, which is 4–10 times greater than the average of other types of vessels and an order of magnitude greater than commonly adopted shipping EFs in the literature. Annual PM_2.5 emission from OSFVs was estimated to be 2.13 (1.18–2.86) kt in Hainan in 2017, comparable to the level of on-road mobile emission there. Our results show that OSFVs are possibly a group of “super-emitters” among marine vessels, which are underrepresented in the shipping emission inventories. Prioritizing regulations for OSFVs is a viable option to mitigate ambient PM_2.5 pollution in Hainan as well as in other coastal regions with active small-scale fisheries in low-income communities.