Where you can see them:
Protea Banks | Aliwal Shoal
TIGER SHARK SOUTH AFRICA
The tiger shark (Galeocerdo cuvier) is a species of requiem shark and the only extant member of the genus Galeocerdo. It is a large macropredator, capable of attaining a length over 5 m (16 ft 5 in). Populations are found in many tropical and temperate waters, especially around central Pacific islands. Its name derives from the dark stripes down its body, which resembles a tiger’s pattern but fade as the shark matures.
The tiger shark is a solitary, mostly nocturnal hunter. It is notable for having the widest food spectrum of all sharks, with a range of prey that includes crustaceans, fish, seals, birds, squid, turtles, sea snakes, dolphins, and even other smaller sharks. It also has a reputation as a “garbage eater”, consuming a variety of inedible, man-made objects that linger in its stomach. Though apex predators, tiger sharks are sometimes taken by groups of killer whales. It is considered a near threatened species due to finning and fishing by humans.
A large head with a very blunt snout and wide jaw but a slender body; large eyes. Vertical stripes fade with age and are barely visible in the adults. A distinct inter-dorsal ridge; the caudal peduncle has lateral keels. The cockscomb-shaped teeth are heavily serrated. Usual tooth count 10/11-1-10/11 / 11-1-11
It favours warmer waters and is rare in the Cape. Occasionally found far out at sea, but more often in turbid, coastal waters. It may enter estuaries.
Males mature around 250 cm (8 years) and females around 274 cm (11 years). Breeding appears to take place well north of KwaZulu-Natal. Aplacental viviparous development. The litter averages 35 pups which are born at 60-70 cm. This species may exceed 700 cm.
It is a most indiscriminate feeder and is best described as a scavenger. An all-embracing diet features marine mammals, turtles, seabirds and a variety of bony and cartilaginous fish and cephalopods. An assortment of such garbage as carrion, tin cups and plastics are also ingested.
This species is usually solitary and more active at night. Although relatively sluggish, it is easily stimulated by food and is extremely dangerous. It is capable of pumping waters over its gills when stationary. Smaller specimens may survive well in captivity
Tiger sharks belong to one of the most popular shark families: the requiem sharks. Many of the best-known sharks—the ones we see the most and the ones that are most abundant in the ocean—are requiem sharks.
Some requiem sharks are aggressive hunters, including tiger, bull, and oceanic whitetip sharks. Some, particularly the oceanic whitetips, are loners. Some are social and spend time with each other, sometimes teaming up to catch prey or to ward off attackers. And some requiem sharks, particularly lemon sharks, seem to like hanging out together.
Their personalities may be diverse, but all 54 species of requiem shark –including the tiger shark – share a few physical traits in common: they’re all good swimmers with strong bodies, small eyes, nictitating membranes (third eyelids), and long fins behind their gills.
A Tiger Shark is seasonally resident on our coast. We say “seasonally resident” as there are distinct seasonal visitations. The big females (3.0m pcl and bigger) join us from January to June. Animals in the size range 3.0m pcl and smaller are best viewed in the period July to December.
We have been baiting areas to the south of the main Aliwal Shoal reef body over the last four years and the success rates have been as follows:
1999: 16 sharks sighted and 97% success rate of sightings per dive
2000: 8 sharks sighted, 83% success rate per dive
2001: 9 sharks sighted, 56% success rate per dive
2002: 18 sharks sighted ad 93% success rate per dive (three sharks tagged with acoustic tags and thus we know better their movements and can, in fact, follow them on a daily and hourly basis)
2003: 17 sharks sighted and 100% success rate per day. Activity at the ground station was poor and thus the surface and subsurface work did us proud. It broke through to new levels of viewing and behavioural understanding.
2004: 20 sharks identified and 100% success rate per day. Some small males in the mix. Three scavenging events documented on turtles and six sharks tagged.
Option one, which is not our preferred option, is to set up baits on the seabed at 15/17m and then observe the sharks as they come to the baits to feed. As many as 8 tigers at once may be expected but typically two or three are the norm at any one time. The animals tend to arrive around 09h00 and stay until the divers leave the site. The group of no more than 8 divers conducts either one or two dives. The most number of passes (a pass is measured to within 1 metre of the diver) in a single dive is 68 by Betty (a 4.5m female) in 2000.
The most number of continuous days without a tiger sighting whilst working on the bottom is five, although we had a White Shark, Hammerheads, Zambezi and Blacktips to take up the slack during this period.
Option two and the most recommended option is sub surface drifting. Over the last two years (2002/3), we started the surface work a la’ the Great White Shark cage diving, but without a cage, and it has been very successful, other than breaching we are getting all the other behavioural stuff that they get with the Great Whites.
Once we arrive at the dive site we start chumming so as to attract the Tigers and pot out a buoy with the bait. When the first Tigers appear the DM assesses the situation and if he is of the opinion that the Tigers are going to stay around awhile and that they are not aggressive the divers may enter the water. Either you can view the action from the “safety” of the boat, or for non-certified divers, on snorkel, and certified divers can drop down to about 5 meters and follow the action from below. This is a drift dive as the boat, chum and bait is drifting with the wind and surface current, as are the divers at 5 meters. Should the sharks disappear the snorkellers and divers climb back onto the boat and we move to another location and start all over again.
Typical visibility is from 5 to 40m and water temperature between 22 and 28 Celsius depending of the time of year. Daytime temperatures range from 20 to 38 Celsius.
This method has delivered 100% success over the past two years. 2003 offered the best animal interaction year so far. 17 sharks presented themselves. Made up of 3 males and 14 females. The biggest animal was a return female, Marion, at 4.0m (pcl). Barbara-Ann arrived back after a year’s absence and was a major player. One of the animals tagged in the 2002 acoustic study (Ashleigh 3.5m pcl) returned and was one of the nine regulars. The longest surface wait at one site was 40 min and the shortest wait was 7 min.
2004 delivered 20 identifiable animals and of these two were males. Ashleigh was back with Ella. Barbara Ann was around for a month and then disappeared and a host of new animals made themselves famous in dive logbooks and on the film circuit.
So far 2005 has continued with a 100% sighting success per day per dive. We have identified 18 sharks and new ones are entering the area on a weekly basis. One animal has returned from the 2004 tagging study and many new faces have been documented this year.
09h00-Meet on the beach to kit up.
- There is no toilet on the boat.
- Light refreshments are included.
- Cylinders and weight belts are provided per diver.
- Please bring suntan lotion and a hat.