Date : Sat 1st September
Location : Swartvlei Beach
Sperm Whale washed ashore.
By Mark Dixon
It is remarkable that in the past two months no less than two whales have washed up on Swartvlei Beach east of Sedgefield.
Even more remarkable is the fact that both whales washed up a few hundred meters apart, testimony to the consistency of currents along the shoreline.
The latest whale to wash up early morning on the 31st August was a Sperm Whale, a rare event with the previous Sperm Whale to wash up on the South African coastline occurring eight years ago.
Sperm Whales belong to the toothed whale family and are well known for hunting giant squid at great depth.
Consuming approximately 900kg of prey per day they dive between 300 and 1200m, though they have been recorded at depths of 2000m.
Holding the record for dive time they average 45 minutes per dive but can spend up to 90 minutes on a dive.
Their lower jaw appears disproportionately smaller to the upper jaw and has evenly spaced conical teeth to grip squid and other prey.
The Sperm Whale that washed up on Swartvlei was 16.37m long, a male and had 36 teeth in it’s lower jaw. The blubber over the abdominal rwgion was 17.3cm thick. From appearances it had been dead for at least a few days but didn’t show any signs of predation or scavenging.
Interestingly, in Sperm Whales the blow hole is positioned slightly to the left of the top of the head which accounts for the distinct sideways blow of this species. Like the Humpback Whale which washed up at the end of June, the Sperm Whale washed lying on its left side and the sand covered the blowhole.
Due to the rarity of a Sperm Whale washing up there were plenty researchers to monitor the carcass and take samples. SMART from Mossel Bay helped with crowd control and Danielle Conry and Frikkie van Der Vyver from the Plett Stranding Network were assisted by Wayne Meyer from Cape Nature in measurements and sampling.
A crucial part of the sampling was securing the teeth from the lower jaw for analysis before trophy collectors and muti collectors could take them. To this end Wayne, assisted by SANParks Rangers used a chainsaw to cut the lower jaw off.
The prospect of muti collectors coming to take samples was confirmed when two spectators were overheard planning a night visit at low tide to harvest all the teeth and tail. It is possible that it is the same people who previously removed the tail from the Humpback Whale.
One of the most asked questions today was what caused the death of the Sperm Whale. While there is no conclusive answer yet, disease, injury from mating conflict or poor nutrition are the top possible reasons.
Report a stranded marine mammal : Contact details and procedure.
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