Shark and bony fish gillnets are the most common causes of incidental mortality in sSAm waters. Directed catches of small cetaceans have also been made to provide cetacean meat for use as bait in crab fisheries, and this may have had an important impact in sSAm populations of L. australis, L. obscurus, C. commersonii and C. eutropia . Direct catch of L. australis has presumably been responsible for the diminishing of sighting frequencies of this species in the Beagle Channel. The direct exploitation of small cetaceans in sSAm seems to be decreasing. However, fishermen occasionally take dolphins and porpoises fundamentally because of their hunter nature, not necessarily for consumption or baiting purposes.
Coastal areas are particularly important to society for fisheries and human populations.
This creates problems because the same areas of ocean that provide food and livelihoods also endure the greatest abuse. These activities affect coastal marine mammals, generating disturbances such as marine pollution, competition for prey availability, and subaquatic noise increase. These factors are not currently considered in the management of coastal zones. As an example, groups of C. commersonii appear to have moved to other less man-influenced areas because of such factors. Considerable pollutant levels are present in this area and facilities have been constructed recently in Corral for wood chip exporting.