A blainville´s beaked whale stranded in the Canary Islands due to an attack of orcas with a review of the strandings of the species in the archipelago

FRANCESCA FUSAR POLI; MARISA TEJEDOR; MANOLO CARILLO; CARLA FIORITO; MANUEL ARBELO; ANTONIO FERNÁNDEZ; VIDAL MARTÍN

Conferencia; 34th European Cetacean Society Conference; 2023

Blainville's beaked whale (Mesoplodon densirostris) is a deep diving cetacean belong to the Ziphidae family, listed as "Least Concern" (LC) by the IUCN and a target species for SECAC monitoring programs to improve the scarce knowledge concerning its biology. On 4 April 2021, a sexually mature female Blainville's beaked whale stranded at La Guirra, Antigua, Fuerteventura Island, on a stretch of coastline integrated into the AMP Site of Community Importance (LIC) "Marine Space of the East and South of Lanzarote and Fuerteventura?. The animal stranded with no caudal peduncle and presented post-mortem shark bites, as well cutaneous tooth rake marks produced by killer whales (Orcinus orca). A systematic necropsy was conducted by the IUSA Institute and a biological study was carried out by SECAC. The provisional diagnosis of death was compatible with intra-interspecific traumatic interactions. This individual was part of a small population of Blainville's beaked whales resident in the water of Fuerteventura and had been photographically identified (with the code Mde 008) 18 years earlier as part of a SECAC beaked whale monitoring program. This specimen shows a characteristic deformity of the rostrum, specifically the left lower jaw suffered an old trauma that, apparently, did not affect its survival. Animal shows a good physical conditions and the stomach analysis revealed an abundant stomach contents with remains of fish, crustaceans and cephalopods, confirming a normal feeding. Between 1983 and 2022, 17 specimens of Blainville's beaked whales have stranded a long the coasts of the Canary Islands. This case exemplifies the value of integrative science through the combination of information from different approaches such as monitoring programs at sea and stranding networks (from the health to the biological perspective) to improve the knowledge and the management of these species and the AMP.