Seal Island is a small land mass located 5.7 km off the northern beaches of False Bay

False Bay

False Bay is a body of water defined by Cape Hangklip and the Cape Peninsula in the extreme South-West of South Africa.- Description and location :...

, near Cape Town

Cape Town

Cape Town is the second-most populous city in South Africa, and the provincial capital and primate city of the Western Cape. As the seat of the National Parliament, it is also the legislative capital of the country. It forms part of the City of Cape Town metropolitan municipality...

, in South Africa

South Africa

The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...

. The island is so named because of the great number of Cape Fur Seals that occupy it. There are a few sea birds as well. It is an outcrop of the Cape granite and rises no more than about six metres above the high tide mark. The island is long and narrow- 800 metres by 50 metres. There is no vegetation or soil of any significance. A radar mast

Radar

Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...

 was built on the island during World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

 by a crew who lived on the island in prefabricated huts for the duration of the construction but this tower gradually succumbed to corrosion and was blown over in a winter storm in 1970. All that remains of it is rusty, twisted metal. There are the ruins of a few huts and other structures from the sealing and guano

Guano

Guano is the excrement of seabirds, cave dwelling bats, and seals. Guano manure is an effective fertilizer due to its high levels of phosphorus and nitrogen and also its lack of odor. It was an important source of nitrates for gunpowder...

-collection era (first half of the 20th century). Some rock inscriptions made by sealers in the 1930s are still evident.

Great White Sharks

The dense population of fur seals at certain times of the year attracts the seal's main predator, the Great White Shark

Great white shark

The great white shark, scientific name Carcharodon carcharias, also known as the great white, white pointer, white shark, or white death, is a large lamniform shark found in coastal surface waters in all major oceans. It is known for its size, with the largest individuals known to have approached...

. Seal Island provides unique opportunities for those who wish to observe attacks by White Sharks on Cape Fur Seal

Cape Fur Seal

The brown fur seal , also known as the Cape fur seal, South African fur seal and the Australian fur seal is a species of fur seal.-Description:...

 and to observe social interactions amongst both species. The island is well known for the interesting way the sharks grab their prey: They come up from underneath and literally launch themselves out of the water with the seal in their mouth. It has been shown that if the seals enter the "Ring of Death" (where the sharks circle the island) on the surface instead of at the murky bottom, they will be picked off by the faster and more aggressive Great White.

Video

• Polaris Attack, in which the shark launches itself vertically out of the water and grasps the seal while in mid-air.
• Surface Pursuit of a Cape Fur Seal by a White Shark at Seal Island.

External links

• "White Shark Predatory Behavior at Seal Island"
• University of Cape Town Avian Demography Unit
• Photographing Africa's "Flying Sharks" from National Geographic's web site