Fast ferries and cetacean collisions: eyidence & solution(s)

Abstract

In the Canarian archipelago, fast ferries started to operate in April 1999. There are two different types: (1) catamaran-type with 40 knots medium speed, operating in the channel between Tenerife and Gran Canaria; (2) monohull-type wittt 30 knots medium speed, operating in the channel between I-a Gomera andTenerife. At least seven individuals from a minimum of four cetacean species have died due to fast fetnes (Bølaenoptera sp. probably B. edeni, Physeter macrocephalus, Ziphius cavirostrß and a medium sized animal, probably Globicephala macrorhynchas). Data are provided by trusted casrral observers, and süanded specimens with heavy cuts. Other cetacean species, or smaller animals such as turtles, may also have suffered collisions but do not strand due to the strong currents in these regions. In addition, commrmities of the protected seagrass Cym.odacea nodasa are being impacted. Dolphin displacement is thought to occru, possibly due to acoustic pollution produced by the catamaran fast ferries. In the channel between Gran Canaria andTenerife, a year-rourd population of bottlenose dolphins showed chauges in distribution pattern, as indicated by the reduction in sightings in their usual area (Agaete), coincident with the commencement of the fast ferry operations in the area. Between L¿ Gomera and Tenerife, there is a resident population of short-finned pilot whales and bottlenose dolphins. In addition, both charmels are crossed by many migratory species, some as the endangered northern right whale (Eubalaern glacialis). The whole archipelago, and in paficular the two channels that are covered by fast ferries, can be considered as a very sensitive area for cetaceans. Part of both channels have been declared Nah¡ra 2000 areas (Special Areas of Conservaûon) because of the presence of Tursiops truncøtus and loggerhead turtle (Carettø carelta) poprfations. Islas Canarias form a critical habitat for a number of cetacean species. Collisions and displacement due to fast ferries should not be permitted. The precautionary principle should be invoked, and the archipelago should be declared a marine sanctuary.