[10] The Weddell seal face has been compared to that of a cat due to a short mouth line and similarities in the structure of the nose and whiskers.

[9] The Weddell seal grows a thin fur coat around its whole body except for small areas around the flippers.

[9] Adults show a counter-shaded colouration that varies from bluish-black to dark grey dorsally and to light grey/silver ventrally.

Weddell seals are non-migratory phocids that move regionally to follow the distribution of breathing holes and exit cracks within the ice changes between seasons.

[12] The species is primarily restricted to Antarctic waters: physical factors, such as glacial movement and tidal action, may increase fluctuations in distributions.

[12] During the first two weeks, mother Weddell seals distinguish their pups through olfactory smells, and specialised vocalisations, and stay in the same spatial area.

[23] Additionally, fast ice breeding grounds cause females to cluster in large aggregations, making it easier for males to control their harem.

[21] The mating season occurs during austral spring between late November and December after pups are weaned and females begin ovulating.

The embryo is not implanted into the uterus until the beginning of austral summer, between mid-January and mid-February, allowing for birth under more favourable environmental conditions.

Sound waves can be transmitted either through the ice itself or from water to breathing holes where female Weddell seals are usually breeding.

Individual Weddell seals can each produce their unique song, but singing behaviour is not common when observed.

Mother Weddell seals use vocalisations to call their pups from further distances when smell can no longer be used efficiently (Opzeeland et al., 2011).

[citation needed] The most recent estimate suggests a population of about 202,000 female seals, based on high-resolution satellite images from November 2011 that cover the full habitat range of the species.

[33] Previous estimates, with lower geographic coverage and thus relying more heavily on extrapolations, tended to be much higher, reporting numbers in the range of 800,000 or so.

[34] Because of the widespread distribution of Weddell seals, population assessments are difficult and expensive to conduct, and therefore infrequently undertaken.

However, thanks to the availability of higher-resolution satellite imagery and crowdsourced data, future counts may be simplified with automated image recognition.

[35] During the early periods of Antarctic exploration, Weddell seals suffered dramatic declines as they were hunted for food and oil.

Research estimates seal populations may decline as the availability of their habitat is extremely temperature sensitive thus making them potentially vulnerable.

[36] Climate changes affecting the duration and the extent of the sea ice and nutrient availability could potentially reduce pups’ survival and may have important implications for population growth rates.

[37] The fact that some populations breed on land (e.g., in South Georgia), could demonstrate the ability of the species to colonise different environments, although the extent of such plasticity is uncertain.

[1] However, the disturbance effects of the increasing seasonal tourism in the Antarctic and Sub-Antarctic on Weddell seal behaviour, distribution, and foraging are still unknown.