Bronze Whaler Sharks
Bronze Whaler Sharks are another big predatory shark species we have around the South African coastline. They are large sharks growing up to 3.5m in length or sometimes even close to 4m as recently recorded in the local area. Their name is derived from their color, being a bronze-grey color. The whaler part comes from the whaling vessels in the 19th century, as this species used to congregate around the carcasses of harpooned whales.
In the last few years, we have been cage-diving with Bronze Whaler Sharks regularly. As Great White Shark population numbers have declined around South Africa, this species has frequented our bay in large congregations during September to April. Sightings increase in the summer months as they come into shallow waters to give birth, breed, and chase their prey. Whilst in the area they are feeding on small fish species like mullet and sardine, octopus, and smaller sharks that swim along the bottom of the sea floor.
Bronze Whaler Sharks are schooling sharks so generally we get more than one shark at a time visiting the cage. This provides our clients with fantastic and often constant shark activity throughout the trip. Sometimes having up to 30 sharks around the boat, being in the cage can be like being in the middle of a big school of sharks!
The males and females of this species do not live together. The females form large schools, whilst the males form smaller schools and tend to only visit the female schools during the breeding season. In Gansbaai, the Bronze Whaler Sharks that we see are predominantly large mature females with the occasional male recorded. There is evidence of breeding occurring in the area as many of the females recorded have bite marks on them. When sharks mate the males bite down onto the sides of the female and we often observe the females with fresh bite marks This indicates that breeding is occurring in the area, making it a significate location for this species.
Bronze Whaler Sharks reproduce in the same way as mammals. They give birth to live young and feed their young through an umbilical cord. Whilst slow growing, only reaching maturity around 15-20 years of age. These sharks are also believed to have long pregnancies of up to 12 months and are therefore vulnerable to exploitation. The population appears to be healthy but they are considered as Near Threatened on the IUCN red list. This is due to their slow growth rate.
This species is found all around the world. Sightings are mostly observed around the coast of South America, Southern African countries, Australia and New Zealand. However, there is nowhere in the world apart from Gansbaai that you can cage dive with these sharks.
While the Bronze Whaler Sharks could be a prey item for large Great White sharks, their presence does not deter the Great White sharks. Over the last few years, we have observed both species on one trip multiple times. The Great White shark is generally a solitary animal. Many individuals have shown to be unphased by the presence of the Bronze Whalers. Nonetheless, when a large Great White shark moves into the area, the Bronze Whaler sharks tend to ‘lay low’. Large Great Whites, over 4m in length could attempt to predate on the adult Bronze Whaler Shark. We have never witnessed a predation but that does not mean it does not happen.
We are predominantly diving with Bronze Whaler sharks during our summer months with occasional sighting of a Great White shark. Our winter months are still dominated by the King of the Ocean. The Bronze Whaler shark leaves during the winter months and follow the sardine run up the Eastern coast of South Africa. We do sometimes observe some individuals left behind in the area whilst our winter months are dominated by Great White shark sightings. Whilst Great White sharks are observed, due to the declining population, we are sadly not observing them in the numbers that we used to.