Cape Town – An aerial survey of southern right whales off the Cape coast by the University of Pretoria (UP) has counted 200 whales in the area – the second-lowest figure since 1995.
The survey by the university’s Whale Unit Mammal Research Institute between September 30 and October 5 followed the City of Cape Town, along with the Shark Spotting Programme, monitoring what it said was “now the complete disappearance of great white sharks from False Bay” earlier this year.
According to the UP unit’s research manager, Dr Els Vermeulen, the survey was conducted between Nature’s Valley and Muizenberg.
“All southern right whales observed along this stretch of coastline were counted, and photographs were taken of the unique callosity pattern on the heads of all individual females with calves as well as all individuals of a brindle grey colouration or white blaze.
"In total, 190 females and calves (95 pairs) of southern right whales were counted and photographed, as well as 10 adult whales without a calf - so-called ‘unaccompanied adults’ - bringing the total to 200 southern right whales,” Vermeulen said.
The numbers mark the second-lowest number of right whales along the shore since 1995.
“This is a huge decrease from last year’s all-time record of 536 cow-calf pairs in the same stretch of coastline,” Vermeulen said.
It is also a strong decrease from 131 cow-calf pairs which were counted between Hermanus and Infanta in August this year.
The reason for the apparent shift in peak presence over the past years, the unit noted, could be related to female right whales giving birth earlier and therefore leaving the South African breeding ground earlier, or that female right whales are leaving the South African breeding ground earlier possibly with a calf that is not ready to migrate.
“Also, the number of adults without a calf - unaccompanied adults being males, resting females and females that should fall pregnant this year - remained extremely low, as it has been since 2009. In fact, the recording of 10 adults without a calf in October is the second lowest count in the past 40 years. In 2016 we only counted nine.
“This tells us that non-calving right whales are still not migrating up to the South African coast as they used to prior to 2009.”
In August, the City said that during last year, the total number of shark sightings recorded along False Bay fell to only 50, and this year there had not been a single confirmed white shark sighting by the spotters.
Nor has the Shark Spotters’ applied research programme detected any of the tagged white sharks on its tracking receivers since 2017.
The Department of Agriculture, Forestry and Fisheries had said white sharks had not completely disappeared from the False Bay area, as some had been spotted by white shark cage diving operators.