Distribution of particulate organic carbon (POC) and dissolved organic carbon (DOC) in seawater, and chemical composition of surficial sediments were studied in relation to pulpmill effluent and dumping of dredge spoil containing wood debris in Alberni Inlet, British Columbia, Canada. The maximum concentration of POC (377–584µg Cl−1) was observed at the surface around the dumping area (5–7 km seaward of the inlet's head), and at the location immediately adjacent to the dump site POC was elevated throughout the water column (50 m). While POC tended to decrease in the surface layer for a distance of about 25km down-inlet, measureable effects of POC in the deeper water did not extend beyond 600m from the dump site. The dump site was conspicuous by the large maximum in C:N ratio (46.3). In contrast, DOC was observed to be highest (4.25mg Cl−1) at the head of the inlet where pulpmill effluent was being discharged and a secondary maximum was found about 10km down-inlet from the dump site. The data suggest that a considerable proportion of the dredge spoil sinks rapidly near the dump site, probably within several hundred metres. Some of the spoil, perhaps low density wood debris may travel considerably further with the surface water where by leaching it may contribute to some extent to the surface DOC before sinking into deeper water.