+27 (21) 418 3823

Seals

An Aquarium staff member stealthily approaches seals to cut them free from ropes and lines. Photograph by Michelle Kirshenbaum An Aquarium staff member stealthily approaches seals to cut them free from ropes and lines. Photograph by Michelle Kirshenbaum

Cutting the noose

Staff members of the Two Oceans Aquarium have devised a successful method to cut the strap bands, rope, fishing line etc from the necks of seals lying on the decks outside the Aquarium.

For some time, Assistant Curator Claire Taylor and Assistant Technical Manager Vincent Calder have been working on various methods to deal with these injured seals, the sight of which has distressed Aquarium staff and members of the public.

Pinnipeds (fin-footed animals) are threatened by our pollution of the oceans of the world.  Seals are often entangled in strapping bands used for packaging. This causes strangulation and ultimately death. Arctic seal species are hunted for their fur. Pinnipeds have to compete with our demands for food and are often blamed for the decrease in species and therefore targeted as “pests”.

More about seals

South African fur seals live in the cold water surrounding the southern tip of Africa.  In order for the seals to stay warm in these waters, they have a thick layer of blubber under their skin and a double-layered coat.

Seals feed on a number of shoaling fish species that occur around the South African coast. Seals are keen hunters and often hunt octopus, crabs and crayfish.

Seals in the wild can swim up to 20km/hour and can remain underwater for about seven minutes before surfacing.  They usually dive to depths less than 50m, but have been known to go as deep as 200m.

Life cycle

Photograph by Dagny Warmerdam Photograph by Dagny Warmerdam

Intricate timing dictates the life cycle of the seal. 

In October the huge bull seals come ashore and fierce territorial battles rage.

The pregnant cow seals arrive and give birth to a single black pup, which is suckled for a year.

Females mate soon after giving birth, but the development of the embryo is delayed for four months. This means that although the gestation period is only eight months, the pups are born a year after mating when the colony comes ashore again.

 

Natural enemies

Great white sharks are the natural predators of seals, but seals are being threatened by increased commercial fishing and the resultant over-exploitation of those fish species which comprise a major part of the seals’ diet.

How to tell seals apart

True seals

True seals have ear holes, but no external ear flaps. 

Their flippers are small and they move on land by "flopping" along on their bellies. 

When swimming, they use their back flippers to propel themselves through the water in the same way as a fish would use its tail.

Fur seals and sea lions

They have external ear flaps and their flippers are larger than those of the true seals. 

They can rotate their back flippers to ensure agility on land. 

When swimming, they use their front flippers to propel themselves through the water.

Walruses

They have no external ear flaps, but like fur seals and sea lions can rotate their hind flippers for agility on land. Both males and females have tusks.