Suspended microplastic and black carbon (BC) particles were determined in surface waters of the Jade system, southern North Sea, including freshwater sources. On average, 64 ± 194 granular particles, 88 ± 82 fibres and 30 ± 41 BC particles/L were recorded. Maximum numbers reached 1,770/L for granules, 650/L for fibres and 330/L for black carbon particles. The distribution along a transect from the inner to the outer part of the Jade system indicates granular particles to be dominant in the inner part, while fibres occur more prominently in the outer part. The distribution of BC particles was more uniform. All freshwater sources including sewage treatment plant effluents discharged microplastics, while BC was encountered only at two of nine discharge points.