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The disappearance of Cape Town’s great white shark population has been well documented.

Those who operate shark cage diving businesses and the like are really feeling the pinch, with many reporting a massive drop in bookings and a surge in cancellations.

Given that the sharks support a cage-diving industry that provides employment for as many as 750 people, these are worrying times.

Cape Town’s whale-watching businesses may seem safe, but now a new study points to a severe drop in numbers there, too.

This from Bloomberg:

A survey of the population of southern right whales off the coast of Cape Town has shown the second-lowest incidence of the aquatic mammals in 24 years and scientists in South Africa are linking the scarcity to climate change.

The release of the findings of the survey, which was undertaken by the Whale Unit of the University of Pretoria’s Mammal Research Institute, comes as the city’s tourism industry is already puzzled by the sudden departure of great white sharks…

The whale survey, which was conducted by helicopter, found 200 of the whales in a stretch of False Bay, down from over 1,000 last year, the university said in a statement. Still, in 2016 only 119 were seen. The changes may be related to climate conditions in the Southern Ocean, which lies off the Antarctic.

Last year, as many as 536 cow-calf pairs in the same stretch of coastline, which was an all-time record.

The disappearance of the sharks is already tough to stomach, and now the dwindling numbers of these 60 metric ton beauties just adds to that loss:

“We believe the whales are not finding enough food, due to changes in the climate conditions of the Southern Ocean, possibly related to climate change,” the unit said. “Right whales eat krill and copepods and with not enough food they cannot store enough energy to complete the costly migration and reproduction. This has implications for population recovery.”

Those changes in the availability of food has a knock-on effect, reports IOL:

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.

Dave Hurwitz

“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.”

If you’ve been wondering why you’ve seen fewer whales this season, here’s your answer.

Sure, it’s not panic stations yet, because last year was a bumper whale season. Given what we’re seeing with the great white sharks, though, I can’t help but feel a little uneasy about the latest survey results.

[sources:bloomberg&iol]