Bronze Whaler Sharks

Since the 31^st of August, we’ve had the pleasure of diving with Bronze Whaler Sharks, also known as Copper Sharks (Carcharhinus brachyurus). Even though Bronze Whalers frequent our waters, when we have Great White Sharks hanging around the boat, we don’t normally see the Bronze Whalers at all – they prefer to stay clear of the bigger fellas.

Due to Orca predation and other environmental factors, Great White Shark sightings have been sporadic during 2017 and going into 2018, making the prediction of their presence impossible. Thankfully though, the brave Bronze Whaler Sharks stepped up to the plate and entertained our clients with their cuteness.

The lesser-known, infrequently-talked-about Bronze Whaler Sharks may be smaller and less spectacular than their Rockstar cousins, the Great Whites, but they can still reach a substantial 3.3 meters in length and weigh in at about 300 kilograms. They are recognized by their narrow, hook-shaped upper teeth, lack of a prominent ridge between the dorsal fins, and plain bronze colour.

They are listed as a Near Threatened species on the ICUN’s Red List, but in our opinion, they deserve to be a protected species too. Especially considering that Bronzies are (unfortunately) favoured by commercial and recreational fisheries and that they are very susceptible to population depletion due to its low growth and reproductive rates. The sharks are caught for their meat, which is usually salted and dried.

Bronze Whalers perform seasonal migrations, in response to temperature/seasonal changes, reproductive events (males and females of the species do not co-exist throughout the entire year), and prey availability (think Sardine Run!).

During migrations, individual sharks have been recorded traveling up to 1,320 km and they are known for returning to the same areas year after year.

The Bronze Whaler Shark feeds mostly on cartilaginous fish, bony small fish and other cephalopods and does not hunt individually. They like to hang out in a pack and the numbers are used to their advantage when encountering a bait-ball of sardines or a larger prey. Generally, they prefer waters above 12˚C and at least 100m deep, but they have been known to sneak into estuaries and they like to hang ten in the surf zone too.

Bronze Whalers, as with all requiem sharks, are viviparous. The litter varies between 7 to 24 pups and gestation lasts for an estimated 18 months. The pups grow slowly and only reach 7ft when they are between 13 and 19 years of age. The average lifespan of a Bronze Whaler is about 25 – 30 years.

They had to dodge the lures of fishermen and the occasional Great White too, but we are very grateful that the Bronzies came to introduce themselves to our clients – Bronzies, you rock too!