2 November 2015
Scientists have set off on a research voyage to collect data on humpback whales between Dassen Island and Groenriviermond off the west coast of South Africa.
Two ships, the Department of Environmental Affairs’ RV Algoa and the Department of Agriculture, Forestry and Fisheries’ FRS Ellen Khuzwayo, left on the expedition on 28 October.
The team on the RV Algoa will focus on environmental sampling for analysis of the chemical make-up of the region – checking the available nutrients, and available food for whales. Researchers will record every whale seen along a pre-designed research path.
Those scientists on the FRS Ellen Khuzwayo will be dedicated to biological sampling of humpback whales encountered in the region – collecting DNA samples, taking photographs of whale tails/flukes and attaching satellite tracking instruments in order to understand their movement and behaviour, both on the west coast and on their return to Antarctic feeding grounds.
“Small cameras will be attached on selected whales using suction cups in order to have a whale’s view of the ocean,” said the Department of Environmental Affairs. “This will help us to identify the prey types on the west coast while supplementing prey sampling from the prey (food) sampled from the RV Algoa.”
The department said it was important to understand the dynamics of the whales for population identification, abundance estimation and conservation management.
“Humpback whales are a charismatic and acrobatic large whale species that typically visits the west coast of Africa every winter for breeding. Upon completion of breeding activities, they begin their 2 500km swimming journey to Bouvet Island, south-west of Cape Town, in late spring/early summer.”
Tourists flock to South Africa to view two types of visiting large whales – the southern right and humpback whale. “These whales gather in South Africa for a feeding frenzy that scientists believe is unique to South Africa in the southern hemisphere,” the department said.
“It is suspected that changes driven by climate change have influenced this ‘unusual’ behaviour. Although an estimated 500 humpback whales are found in South African waters, no evidence of breeding has been recorded off the west coast of South Africa, raising questions around their breeding locality.”
The research is being done in conjunction with the departments of Environmental Affairs and Agriculture, Forestry and Fisheries; the University of Pretoria’s Mammal Research Institute; the National Oceanic and Atmospheric Administration (USA); Oregon State University (USA); Aqualie Institute (Brazil); and invaluable contributions from BirdLifeSA and the Australian Department of Environment’s Marine Mammal Centre.