The Fraser’s Dolphin is typically a tropical oceanic species occurring in deep offshore waters, often in large schools. Sometimes it can be seen near shore in some areas where deep water approaches the coast such as around volcanic archipelagos, in the Philippines, the Lesser Antilles, the Indian Ocean, and Macaronesia (Perrin et al. 1994, Dulau-Drouot et al. 2008, Kiszka et al. 2010, Gomes-Perreira et al. 2013). Sightings seem to be related to preferred sea surface temperatures reported SST tropical surface waters including from 22.9 to 27.7°C in the Atlantic Ocean (Leatherwood et al. 1993, Weir et al. 2008, Yoshida et al. 2010, Gomes-Pereira et al. 2013). They are rare in coastal waters over the continental shelf.

Europe
In the Azores and Madeira archipelagos, Fraser’s Dolphins were found in water depth between ~700 and 2,200 m, in August when SST are warmer than the rest of the year (Gomes-Pereira et al. 2013). The authors found that in situ recorded SST (~25–26ºC) and the MODIS SST-derived average of ~24ºC for the month of August 2008 in the Azores corresponded to a high positive anomaly compared to the previous decades, and particularly high in the days preceding the sightings. Conversely, the SST derived from MODIS in Madeira in 2010 (22.9ºC) was normal for the season.

Fernández et al. (2009) analysed the stomach contents of a female individual (2 m) stranded in Lanzarote in April 2005. The prey remains included lower and/or upper beaks from at least six cephalopod species, five oceanic (Todarodes sagitattus, Taonius pavo, Mastigoteuthis sp., Histioteuthis type A and Braquioteuthis sp.) and one coastal (Enoploteuthis sp.). The cephalopod Histioteuthis type A contributed with 64% by number and 67% by weight of the total prey biomass. Four mesopelagic and nectobenthic species (Trisopterus sp., Micromesistius poutassou, Merlangius merlangus and Sepia sp.) were found in stomach contents of the individuals stranded in northern France. These preys suggest that Fraser's Dolphins fed on the continental shelf of the northeastern Atlantic.

Global
The water depth of both the Gabon sighting (556 m) and the recent Cape Verde sighting (~500 m; Torda et al. 2010) were shallower than the previously-recorded depths in the eastern tropical Atlantic which ranged from 1,371 to 1,874 m (Weir et al. 2008). This confirms that the Fraser’s Dolphin is found along the upper slope as well as in deeper areas.

Fraser's Dolphins are relatively high trophic-level oceanic predators and feed mostly on mesopelagic fishes (myctophids), cephalopods, and crustaceans (Dolar 2018, Kiszka et al. 2011, Dolar et al. 2003, Wang et al. 2012). Physiological and dietary studies indicate that Fraser’s Dolphins are capable of quite deep diving and that they do most of their feeding deep in the water column, in waters up to 600 m deep. However, they have been observed to feed near the ocean surface (Watkins et al. 1994). They are frequently observed in association with other species, particularly Pantropical Spotted Dolphins (Stenella attenuata) and Melon-headed Whales (Peponocephala electra).

The exact distribution of this species is poorly known. Fraser's Dolphins have a pantropical distribution worldwide, largely between 30°N and 30°S in all three major oceans (Jefferson and Leatherwood 1994, Dolar 2018).

In the western North Atlantic, it is regular in the Lesser Antilles of the Caribbean (Gero and Whitehead 2006), and occasionally reaches Florida (Gomes-Pereira et al. 2013, Dolar 2018). It has been poorly documented in the eastern North Atlantic, and very rare in European subtropical waters. Two extralimital strandings occurred in temperate European waters likely connected with temporary oceanographic anomalies. The first one was a sighting of about 30 individuals followed by a mass stranding (11 individuals) on the French Atlantic coast of northern Brittany (not shown on map) in 1984 (31 May-26 June) corresponding to a world-wide El Niño phenomenon (Van Bree et al. 1986, Dabin 2022). The second was a single stranding record from the Outer Hebrides, northwest Scotland, in 1996 (Bones et al. 1998; not shown on map). The species has not been recorded in the Mediterranean and Black Seas (ACCOBAMS 2021).

Few sightings have been recorded in European Macaronesia. The only two confirmed sightings in the Azores Archipelago occurred one day apart in August 2008 south of Pico Island, as observed by whale-watching boats (Gomes-Pereira et al. 2013). Both sightings were of groups around 50 animals, but the authors could not confirm if they were the same animals as they had different age/sex composition, and showed drastically distinct behaviours and responses towards the boats. In the Madeira Archipelago, a few sightings exist from the south of Madeira Island. Fraser’s Dolphins were first observed in October 2003, when a school of 25 animals was sighted by a whale-watching operator. In subsequent years, whale-watching companies sighted the species a few times: in April 2005 (75 animals), November 2008 (4 animals), two sightings in the same day (probably the same group) in August 2010, and another sighting in 2015 (Freitas et al. 2012, Gomes-Pereira et al. 2013, Alves et al. 2018). A possible sighting was reported by several whale-watching companies in July 2022 but no image is available for confirmation (Azul Diving Center, pers. comm.).

In the Canary Islands, the first record of Fraser’s Dolphins was a stranding event in August 1983 in Tenerife, Canary Islands (Martin and Volk 1990). From 2000 to 2018, a dozen strandings were reported, representing about 1% of cetaceans stranded in the Canary Islands (Gobierno de Canarias 2018). Seven sightings of the species were recorded in five islands of the archipelago (Gobierno de Canarias 2022).

Even in the eastern tropical Atlantic, which should correspond to their preferred latitudinal range, reports are very scarce, with very few strandings and even less at-sea sightings recorded in the last decade in Ghana, Gabon, Angola (and probably Nigeria) (reviewed in Weir et al. 2013). The northernmost record on western African coast was a skull from Senegal found in 1997 (Van Waerebeek et al. 2000). The only place with repeated observations is Cabo Verde archipelago. The species was first recorded in August 2003, with a sighting of 20 animals, including juveniles, southwest of São Nicolau Island and an immature female stranding in the southern coast of Boa Vista Island in March 2006 (Torda et al. 2010). More recently, two strandings of adult individuals were reported in Boa Vista Island, one of a dead animal in February 2014 and the other of a live animal returned to the sea in July 2015 (Berrow et al. 2015). The authors also report a mixed sighting of Fraser’s Dolphins (aprox. 150 individuals), melon-headed whales (>100 animals) and a few short-finned pilot whales in late August 2015. The group size recorded off Gabon fell within the documented range of 20 (Torda et al. 2010) to 120 (Weir et al. 2008) animals.

The geographic range of Fraser’s Dolphins seems to be warm-water limited. A predicted increase in sea temperatures due to climate change might cause the species to expand northwards in the North Atlantic (MacLeod 2009). This may result in a greater occurrence of the species in European waters in future decades, possibly with a regular presence in southern Macaronesia (Canary Islands, Madeira) and seasonal incursions in higher latitudes of the Azores, the Iberian Peninsula and/or the Mediterranean Sea.

The Fraser’s Dolphin does not regularly occur in the European Mammal Assessment region, so there are no specific conservation measures for the species in this area. They are protected from deliberate disturbance, capture or killing under the EU Habitat Directive as for all other cetacean species within EU27 waters.

Fraser’s Dolphins are listed on Appendix II of the Convention on Migratory Species, and are protected by some instruments of this convention, such as the Agreement of ACCOBAMS (Mediterranean and Black Sea and the adjacent Atlantic area), which does not cover core habitats, and the Memorandum of Understanding of Western African Aquatic Mammals (Western Africa and Macaronesia).

Research and monitoring is required to understand the distribution and occurrence trends in the European region.