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A study was conducted in the waters off the coast of Archipelago de La Maddalena (Italy) to determine the impact bottlenose dolphins had on gillnet fisheries targeting a variety of fish species. The study showed that the catch per unit effort of target species was significantly higher when there were no dolphin interactions. There were also differences in the species composition of nets attacked and not attacked by dolphins. Those nets attacked by dolphins showed a reduction in the catch of cuttlefish and red mullet while catches of scorpionfish increased.

A study was conducted on observed interactions between a Portuguese purse-seine fishery and cetaceans. Cetaceans, primarily common dolphins (Delphinus delphis), were present during 16.9% of fishing events. The majority of these occurrences happened during the summer and early fall, and during the night. The presence of cetaceans was significantly linked to sardine catches, effort and latitude/longitude. Encirclement of cetaceans occurred in 2.3% of fishing events, with moralities occurring in 1%.

A survey was conducted with fishers in Galicia Spain to investigate interactions between fishing gear and cetaceans. Cetacean fishery interactions appear to be frequent events. Although the damage to the catch and fishing gear were generally reported to be small, substantial economic loss can result from interactions with common bottlenose dolphin (Tursiops truncatus) and coastal gillnet fishing gear, and from short-beaked common dolphins (Delphinus delphis) interactions with purse seine fisheries.

Three types of bycatch reduction devices (BRD) [turtle excluder device (TED), square mesh codend (SMC) and fisheye (FE)] were tested aboard shrimp trawl vessels. Differences in catch from nets equipped with a BRD on one side and a standard net on the other were compared for each of the three BRD's. Use of the TED resulted in no captures of sea turtles or large animals, and did not significantly reduce shrimp catches or fish bycatch.