Seal diving in South Africa

Many of us have dived in the Cape with the pristine beauty of nature above and below the water level. We have seen seals on the water surface basking with their flippers in the sun and up close and personal at the Two Oceans Aquarium, but what do we really know about them and how to behave if they visit us on a dive?

By Amilda Boshoff

The Cape fur seal (Arctocephalus pusillus), is also known as the Brown fur seal or South African fur seal. The Cape fur seal is the most common species in southern African waters and is found from Namibia on the west coast to East London on the east coast. They breed on offshore islands and in large mainland colonies along the west coast. Seals have streamlined, elongated bodies, with limbs modified as flippers with which they can swoop past kelp and turn on a penny to avoid collision with an object or a fellow seal.



The largest of the southern hemisphere's fur seals is the Cape fur seal. They are agile swimmers who spend much of their life at sea, feeding on squid, rock lobster and pelagic fish. While swimming they can reach a speed of up to 16km/h. The seals breed in mid-October, and unlike many eared seal species, females are free to choose their mate and he is judged based on the value of his territory. Bulls gather gregariously on sandy beaches, rocks and coastal islands and the cows arrive a few weeks later to give birth to a single pup after a gestation period of 11-12 months. Bulls establish a harem of up to 50 females for one male and mating takes place about one week after the cow has given birth to the single pup.


After giving birth, females take turns to forage at sea while the others suckle their young and look after the other pups in the rookery. Each pup recognises its mother’s scent and call and visa versa and the mother suckles the pup after coming back from the sea. Pups are suckled for 8-10 months but the pup will also be foraging on its own from the age of six months, during which time it will learn the hunting skills it will need as an adult. At the end of December, the breeding colonies break up, just to gather again the next year. Other than mating, the bulls don’t have any role in parenting the pups.

Cape fur seals are inquisitive and friendly animals when in the water and will often accompany scuba divers on a dive. They will swim around for several minutes at a time – even at depths of 60m - but on land they are far less relaxed and tend to panic when humans come near.

The Cape fur seal's main predator is the Great white shark, but the seals employ a number of strategies to stay alive while in shark-infested waters, such as swimming in large groups, darting in different directions to cause confusion when attacked and riding near the dorsal fin to keep out of reach.

 

Diving with seals

Cape Town provides some of the most beautiful dive destinations in South Africa, with December to February being the best time to dive on the Atlantic side. After a South-westerly wind, visibility can clear up to 20m, but with this the chill factor also increases. Locals recommend diving in dry-suits or a good quality 7mm two-piece wetsuit –don’t forget the gloves and hoodies! False Bay can be dived almost all year round, although April to September is the best time to dive shipwrecks as the water is much clearer, but also much, much colder, reaching temperatures of around 10ºC thanks to the North-westerly wind.

Not too many people know that seal diving and seal snorkelling is one of the favourite pastimes of the local divers, and being surrounded by playful and curious seals is great fun. Diving with the Cape fur seals is done at Duiker Island, about 10 minutes by boat from Hout Bay where large populations of seals gather during the year. The pups are very friendly and will swim close to divers and playfully nudge at fins. This proves to be an ideal photo opportunity, but you have to be quick as they are not the posing kind! Diving is done right next to the island in only 5m of water and the divers descend straight to the bottom and observe the seals playing around. Remember that no touching is allowed as they are wild animals and they definitely have a sharp side, so be warned… With the shallow depth there is more light penetration and the magnificent colours of the surrounds are highlighted. On your next dive trip to the Western Province, be sure to book a seal dive and enjoy the company of the friendly Cape fur seals.

Did you know?

  • Fur seals forage up to 220km from their colony.
  • At the age of seven months, pups can stay at sea for up to four days swimming and hunting.
  • Seal harvesting was only banned in South Africa in 1990.
  • Seal harvesting is still legal in Namibia and is practiced up to this today.
  • Research has revealed that seals or pinnipeds are descendants of a bear-like ancestor that roamed the earth 23 million years ago.
  • The smallest seal on record is the Galapagos seal that weighs just 30kg, The largest seal is the Southern bull elephant seal that weighs over 2 000kg.
  • Seals have whiskers that help them to navigate.
  • Seals have a big layer of fat under their skin which serves to keep the animal warm in the winter but also helps with buoyancy.
  • When diving in the water, a membrane covers the eyes of the seal for protection.
  • Seals conserve oxygen longer under water and are able to resist more pain and fatigue than other mammals.
  • Seals have more blood for their body size than any land animal.

Author: Amilda Boshoff