Killer whale (Orcinus orca) is frequently encountered in coastal and high productive pelagic waters, near the shelf break. In the south-western Atlantic Ocean, spatial and temporal occurrence patterns are poorly known. However, the monitoring of the interaction between killer whales and longline fishery suggests that the species is frequent in this region. We analysed the killer whale presence within the Uruguayan pelagic longline fishing zone. Data were collected from 1996 to 2007, during 2189 fishing events, by vessel skippers and on-board observers. We estimated the sighting rate (SR = sightings days/fishing days * 100) for different time scales and in 1 × 1 degree grids. Generalized linear models were used to evaluate the effect of spatial, temporal, environmental and operational variables on the species presence. Killer whales were sighted in 100 fishing days (SR = 4.5%), this occurrence being explained by distance from shore and sea surface temperature, varying among months and fishing boats. Although sightings occurred year round, they were more frequent in autumn and winter, at 150–400 nautical miles (nm) from shore (mean = 250 nm) and in waters with temperatures ranging from 19 to 24°C (mean = 22°C). Sets took place between 19°–40°S and 21°–54°W, while killer whales occurred mostly from 34°–37°S and 48°–53°W. In this region, the high productive Brazil—Malvinas Confluence Zone is located, and concentrates fishing effort and also killer whales.

Data were collected on the species richness and abundance of fishes at two sites in the Salonga National Park, Democratic Republic of Congo. Thirty species were identified out of a total of 1,180 fish caught. Claria buthupogon and Synodontis nigriventris (respectively 4.7 and 3.5 catches per net-night) were the most abundant species. Twenty-six other fish species were reported from interviews with local people. Conservation concerns are the burning of breeding sites, use of chemicals for fishing, and the newly introduced practice of dynamite fishing. The effects of these practices in the Park have yet to be documented, but it is likely that these fishing techniques are having negative effects on the fish fauna and urgent action is required to curb such activities, at least within the Park.