The distribution of the spectacled porpoise is thought to be circumpolar, and it is considered a predominately oceanic species, however occasional sightings and specimens are documented in coastal regions.

In the south-western Atlantic records have been made at Santa Catarina in Southern Brazil,[9] Uruguay, from Buenos Aires to Tierra del Fuego, and the Falkland Islands and South Georgia.

In the Tierra del Fuego region, studies estimate that young porpoises are born at 100 centimetres (39 in) long in late spring or summer (November to February).

The species was named by the French-born Argentinian zoologist Fernando Lahille in 1912 for its two distinctive black eye patches, with the latin dioptrica meaning ‘spectacled’.

[12] Recent analyses of mitochondrial DNA from 50 porpoises indicated high levels of genetic diversity that would indicate a large and stable population, or one with a wide distribution.

[3] It is possible that Passive Acoustic Monitoring (PAM) for spectacled porpoises may shed more light on their range and habitat use, however no studies have been conducted to date.

The spectacled porpoise is likely prey for sharks, leopard seals (Hydrurga leptonyx) and killer whales (Orcinus orca).

In Tierra del Fuego, it has been observed that scavenging birds such as kelp gulls will target stranded spectacled porpoise carcasses over other cetacean species.

[16] Researchers have uncovered spectacled porpoise remains within the kitchen middens of the canoe people who lived in Tierra del Fuego between 6000 and 1400 years ago.

[1] Porpoises and other small cetaceans are particularly at risk of entanglement and drowning in gillnets, as the thin filaments are not easily detected by their echolocation clicks.

While it is widely accepted that spectacled porpoises are threatened by fishery bycatch and entanglement, and stranding rates in Tierra del Fuego may be unsustainable for the population, the category of Least Concern has been applied provisionally until more data is available.

The porpoise died five days later on 29 March 1997, and a necropsy revealed damage to the oesophagus and first stomach caused by intubation during force-feeding.