The species prefers warm temperate to tropical habitats (MacLeod et al. 2006), and its distribution is correspondingly limited to the southernmost areas of the European assessment region. In particular, the Canary Islands appear to be of high importance for this species (Tejedor et al. 2011). Similar to other mesoplodonts, it likely inhabits deep waters along, or seaward of, the continental slope throughout its global range (Claridge et al. 2015, McLellan et al. 2018). Twenty-seven encounters off Lanzarote and Fuerteventura in the Canary Islands occurred in water depths of 789 to 1,950 m (mean 1,299 m) and at distances of between 3.3 and 32.4 km from shore (V. Martín unpublished information).

The ecology of Gervais’ Beaked Whales in the European assessment region is poorly understood, due to the low number of confirmed records. It is not known to undertake marked seasonal movements, and strandings and sightings in the Canary Islands have occurred in all months, indicating a year-round presence of the species in that archipelago (Martín and Tejedor 2009; V. Martín pers. comm.). A photo-identification recapture of an adult male after 1,108 days and with 19 km between the capture and recapture locations, suggests some degree of site fidelity and residency within the Canaries (V. Martín unpublished information).

A fatty acid-foraging dive depth model predicted that Gervais’ Beaked Whales in the Bahamas had a mean foraging depth of 1,080 m (Claridge et al. 2015). Stomach remains indicate that the species predates cephalopods, fish and crustaceans (Norman and Mead 2001, MacLeod et al. 2003). The stomachs of stranded Gervais’ Beaked Whales in the Canary Islands have contained the remains of mesopelagic and bathypelagic fish (Chauliodus and Myctophidae) and several cephalopod species including Histioteuthis meleagroteuthis, Chiroteuthis veranyi and Taonius pavo (Martín et al. 1990, Santos et al. 2007, Fernández et al. 2009). Mesopelagic crustaceans are also recorded commonly in the stomachs of stranded animals, and may be an important but under-recorded prey component due to their rapid digestion (Vidal Martín, unpublished information).

In the Canary Islands, the species is usually sighted alone or in small groups of 2 to 6 animals (mean = 2.3 animals: Vidal Martín, unpublished information). Of 30 sightings recorded off Lanzarote and Fuerteventura between 2007 and 2010, five contained calves, and the calving period was considered to span the full summer (Tejedor et al. 2011). Strandings in the Canaries are biased towards females (Martín and Tejedor 2009).

Global
Similar to most Mesoplodon species, the distribution of Gervais’ Beaked Whale has primarily been documented from strandings. Sightings of the species at sea are scarce, both due to the cryptic behaviour typical of beaked whale species and the difficulties with distinguishing it from similar mesoplodonts, especially True’s Beaked Whale (M. mirus: Aguilar de Soto et al. 2017).

It is endemic to the Atlantic Ocean, where it is distributed in oceanic habitat across the warm temperate and tropical waters of both hemispheres (MacLeod et al. 2006, Bachara and Norman 2014). It appears to be more common in the western Atlantic, where it occurs from Brazil to New York (USA), including the Gulf of Mexico and the Caribbean Sea (Norman and Mead 2001). In the eastern Atlantic, its range extends from Namibia to Ireland and the U.K. of Great Britain and Northern Ireland. Strandings have also occurred at Ascension Island in the central South Atlantic (Mead 1989).

European
The species has been reported from the warmer waters located in the south of the Pan-European assessment region. The vast majority of European records originate from the Canary Islands (Martín and Tejedor 2009, Carrillo et al. 2010, Tejedor et al. 2011), where the species appears to be more cryptic than rare. There have been 24 strandings involving 29 whales (including two mass stranding of three animals) between 1985 and 2022, along with 75 verified sightings (Vidal Martín, unpublished data).

North of the Canary Islands, a sighting of two animals was recorded in July 2016 during the SCANS-III survey, 220 km north-west of Galicia in Spain (data provided by Phil Hammond, Sea Mammal Research Unit). A small number of strandings have been reported from Madeira (Freitas et al. 2012), the Azores (Reiner et al. 1993), mainland Portugal (Sequeira et al. 1992, 1996), the Andalusian coast of southern Spain (Valverde and Galán 1997, Bellido et al. 2008), and the Biscay coast of France (Réseau National Échouages: www.observatoire-pelagis.cnrs.fr). Strandings in the cooler waters north of this region are rare. The type specimen was found floating in the English Channel in 1848 and taken to France, where it was described by Gervais (1855). A single stranding occurred on the west coast of Ireland in 1989 (Rogan and Hernandez-Milian 2011), and appears to be the northernmost record of the species in the eastern Atlantic.

There is also one confirmed stranding in the Mediterranean Sea, comprising a female that stranded in Italy in 2001 (Podestà et al. 2005). However, the species is considered a vagrant in the Mediterranean (ACCOBAMS 2021). Other strandings reported from Turkey and Egypt, were likely misidentified Cuvier’s beaked whales (Ziphius cavirostris: ACCOBAMS 2021).

It is included on Appendix III (protected species) of the Convention on the Conservation of European Wildlife and Natural Habitats (Bern Convention). It is included with all cetaceans on Annex IV Council Directive 92/43/EEC on the Conservation of Natural Habitats and of Wild Fauna and Flora (the Habitats Directive) as a species requiring strict protection across its entire natural range within the EU. All Mesoplodon species are included in Appendix II (species that are not necessarily threatened with extinction but may become so unless trade is closely controlled) of the Convention on International Trade in Endangered Species (CITES), which requires an export permit or re-export certificate for international trade.

It is included in two regional management agreements in Europe, comprising the Agreement on the Conservation of Cetaceans of the Black Sea, Mediterranean Sea and contiguous Atlantic area (ACCOBAMS), and the Agreement on the Conservation of Small Cetaceans of the Baltic, North East Atlantic, Irish and North Seas (ASCOBANS). These agreements aim to maintain favourable conservation status of cetacean species within their defined areas, managing threats and working towards the long-term sustainability of populations.