The Department of Environment, Forestry and Fisheries (DEFF) has noted with concern reports from members of the public about the harassment of whales super-groups* by boat and drone operators along the West coast of South Africa.
This follows reports that a larger than usual number of whales (super-groups) is feeding off the West coast of South Africa. The localities of these feeding super-groups coincide with areas of high vessel traffic.
For this reason, 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.
Whales are protected by law in South Africa. The National Environmental Management: Biodiversity Act: Threatened or Protected Marine Species Regulations is clear that, except under a permit specifically allowing one to approach closer, we all need to keep 300 meters away from any whale. Even under these permitted circumstances, it is still required that permit holders prioritise safety of humans and welfare of animals. There is a high possibility that whales can abandon an area if disturbed too much.
While the Department is still collating more evidence to better estimate current numbers, during the recent (04-15 November 2019) whale research cruise, the largest group was between 150 and 200 animals. Recent reports from private aerial photographers, are suggesting that more whales may have since joined the group.
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.
The Department initiated research on large whales under its Top Predators Research Programme in 2014. This research, conducted in collaboration with strategic academic partners, led to the discovery of a "feeding ground" away from traditional feeding grounds in Antarctica. Subsequently annual spring research cruises visited known feeding hotspots. In 2017, a scientific peer-reviewed paper (Findlay et al. 2017) was published describing the groups, the maximum of which constituted 200 animals. This led to some euphoria in wildlife photography and cetacean research spaces. While the Department and partners continue to monitor these feeding groups, we are far from understanding ecosystem-wide impacts or benefits and potential human/whale conflicts.
It should be noted that feeding around tropical and subtropical coastal waters is not uncommon in humpback whales. These have been reported to be opportunistic in nature and unpredictable. However, the feeding super-groups off the West coast of South Africa have been predictable and these 'feeding frenzies' have been encountered consistently since 2014. Feeding frenzies take place during Spring/Summer months with a peak in November. This offers evidence that the West coast of South Africa (particularly upwelling regions) are critical to the whale population occurring off the West coast of Africa.
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.
*Super-groups are defined as groups of 20 or more tightly-spaced individual humpback whales each estimated to be within five body lengths of their nearest neighbour.
Issued by: Department of Environmental Affairs, Forestry and Fisheries