Few things compare to the adrenalin rush and exhilaration one gets from being face to face with a 3 m Great White, especially when they curiously cruise right up to the cage and eye you within kissing range!
The great white shark is certainly one of the most infamous marine species inhabiting the Dyer Island area. South Africa became the first country to officially protect the great white shark, and Dyer Island Cruises is responsible for introducing thousands of people every year to this increasingly endangered species.
Cape fur seals are “endemic” to Namibia and South Africa. They are mammals, like us, which means they give live birth and feed their young with milk. They eat mostly boney fish, but do also eat squid, octopus, or crayfish if they find it. Female seals and their young are present year round and an adult female seal can weight around 80kgs. Fully grown male seals, or “bulls” can weight upwards of 300kgs, so you can definitely see the difference in their size! Bull seals are only present during the breeding season from November/December of every year. This is when male seals set up “harems” or territories of females to mate with. A female will raise one pup per year, and it is estimated that Geyser Rock can produce 10-12,000 seals pups per year (but not all survive their first year). Cape fur seals are famously the main prey for great white sharks.
Diet – Why would a seal eat a penguin?
More research needs to be done in order to understand the complex ecosystem surrounding Dyer Island. It is thought that small groups of “rogue” seals, typically young males, specialize in predating on seabirds. They do not consume the whole bird, but rather target the stomach cavity of returning birds. Returning birds are typically full of fish from foraging, so the seals are really after the fish meal inside destroying the bird in the process.
There is an especially delicate system at Dyer Island where penguin and seal colonies neighbor each other. Therefore, understanding the complexities of this system are imperative to the survival of the penguins.
The African penguin (Spheniscus demersus), also known as the jackass penguin and black-footed penguin is a species of penguin, confined to southern African waters. It is also widely known as the “jackass” penguin for its donkey-like bray, although several related species of South American penguins produce the same sound. Like all extant penguins it is flightless, with a streamlined body, and wings stiffened and flattened into flippers for a marine habitat. Adults weigh on average 2.2–3.5 kg (4.9–7.7 lb) and are 60–70 cm (24–28 in) tall. It has distinctive pink patches of skin above the eyes and a black facial mask; the body upperparts are black and sharply delineated from the white underparts, which are spotted and marked with a black band. This pink gland above their eyes helps them to cope with changing temperatures. When the temperature gets hotter, the body of the African penguin sends more blood to these glands to be cooled by the air surrounding it. This then causes the gland to turn a darker shade of pink.
The African penguin is a pursuit diver and feeds primarily on fish and squid. Once extremely numerous, the African penguin is declining due to a combination of threats and is classified as endangered. It is a charismatic species and is popular with tourists.
Bottlenose dolphins are well known as the intelligent and charismatic stars of many aquarium shows. Their curved mouths give the appearance of a friendly, permanent smile, and they can be trained to perform complex tricks.
In the wild, these sleek swimmers can reach speeds of over 18 miles (30 kilometers) an hour. They surface often to breathe, doing so two or three times a minute. Bottlenose dolphins travel in social groups and communicate with each other by a complex system of squeaks and whistles. Schools have been known to come to the aid of an injured dolphin and help it to the surface.
Bottlenose dolphins track their prey through the expert use of echolocation. They can make up to 1,000 clicking noises per second. These sounds travel underwater until they encounter objects, then bounce back to their dolphin senders, revealing the location, size, and shape of their target.
When dolphins are feeding, that target is often a bottom-dwelling fish, though they also eat shrimp and squid. These clever animals are also sometimes spotted following fishing boats in hopes of dining on leftovers.
Bottlenose dolphins are found in tropical oceans and other warm waters around the globe. They were once widely hunted for meat and oil (used for lamps and cooking), but today only limited dolphin fishing occurs. However, dolphins are threatened by commercial fishing for other species, like tuna, and can become mortally entangled in nets and other fishing equipment.