Cape Town - The Department of Environment, Forestry and Fisheries on Friday said it was concerned about the harassment of so-called whale super groups off the West coast by boats and drone operators.
Noting that their regular appearance in South African water was an important natural phenomenon, the department reiterated that by law everyone, except special permit holders, had to keep 300 metres away from any whale.
"The department would like to urge all vessel masters, skippers, tour boat operators, wildlife photographers/videographers and other interested parties, such as, sunset cruise operators, to exercise the necessary restrained and caution.
"The maritime industry, academia, permitted Boat Base Whale Watching (BBWW) operators, permitted photographers/videographers, tourists and South Africans at large, are urged to enjoy the spectacle in the most responsible way so that we can enjoy their presence in our waters for years to come."
Super groups refer to at least 20 or more whales feeding in close proximity, defined as less than five body lengths, from each other. In early November, a group of between 150 and 200 hump back whales were spotted.
According to the department, such groups have been spotted off the West Coast regularly for the past five years.
The department says super groups have been spotted in with high boat traffic, hence the call for boat operators to exercise restraint. Even those with special permits who are allowed closer to the animals, should be mindful of the safety of the whales, the department says.
"The groups spent a fair amount of time off St Helena Bay and have recently been reported off Saldanha Bay. These whales will eventually make their way South towards Table Bay, another vessel hotspot.
"There is a high possibility that whales can abandon an area if disturbed too much."
It said it was still collecting data but the group spotted in November, appears to have increased in size in the past month.
The department has been involved in scientific research with academic partners. It said it continued to monitor whale feeding groups but added "we are far from understanding ecosystem-wide impacts or benefits and potential human/whale conflicts".
It raised a possibly link between an increase in super group feeding and the climate change, saying these feeding frenzies have been observed consistently since 2014.
This offers evidence that the West Coast of South Africa (particularly upwelling regions) are critical to the whale population occurring there.
There is emerging evidence that climatically driven change in the availability of whale’s main prey (in Antarctica) directly affects their condition and by default, their reproductive success in calving and mating grounds.
Recently there has been an absence or low numbers of humpback whales at South-Western Indian Ocean breeding grounds, which emphasises the importance of the feeding grounds off the West Coast (Atlantic Ocean).
Further research conducted by the Department in 2019 off the East coast indicated a possible alteration of migratory patterns, including timing. Possible research questions include: Are the whales running out of energy reserves such that they are initiating migrations earlier?
Scientists are meeting at the Society of Marine Mammalogy’s conference in Barcelona (Spain) to continue these discussions.
In the context of a changing environment, the West coast feeding grounds may prove to be more important than we initially thought. In 2019, the department scientists and external partners noted a larger than usual number of whales feeding off the West Coast of South Africa.
This year’s numbers are reminiscent of 2014 estimates. The Department is still collating more evidence to better estimate current numbers.