Citizen science research is revealing a graphic picture of just how much whale populations have bounced back in the South Atlantic after being decimated by years of commercial whaling.
With year-round sightings of humpback whales, southern right whales and Bryde’s whales, South Africa’s Western Cape has recently been described by South Africa’s Daily Maverick as a ”whale superhighway.” The year-round whale activity has enabled one dedicated citizen scientist, Alex Vogel who is southern Africa’s data manager for the HappyWhale initiative, to identify an incredible 2,893 different whales in 4,253 separate encounters. To put that in context, in just six years, the number of individuals catalogued by HappyWhale in southern Africa has grown from just 70 to more than 12,000.
And without wanting to submerge everyone is a sea of statistics, in just the last four months alone, the wider citizen science effort in Southern Africa has resulted in an extraordinary 1000 encounters with 500 different individual cetaceans.
Chris Wilkinson of South Africa’s Mammal Research Institute’s Whale Unit provided insight into the region’s year-round whale activity for the Daily Maverick article:
January to April: Bryde’s whales dominate the scene, following sardine migrations along the East Coast;
March to May: Killer whales, though present year-round, are most active during these months as they hunt dolphins and other prey;
May to November: Humpback whales are at their peak, migrating along the Western Cape’s coastline in large numbers; Vogel notes that in just one month, a humpback supergroup spotted on the West Coast included an astonishing 297 individuals.
June to November: Southern right whales arrive for calving season, particularly visible off Hermanus and De Hoop;
November to February: Humpback supergroups form, showcasing dramatic feeding behaviours
The surge in data gathering for South Africa is largely due its human populations being located close to the oceans. Range maps for cetaceans have more of a blind spot when it comes to South Atlantic areas of the ocean north of the Western Cape and in particular the desolate and underpopulated coastlines of Namibia and Angola.
The West Coast’s growing reputation as a whale-watching hotspot presents exciting opportunities for tourism, research and conservation. Simon’s Town and Kalk Bay, both with high sightings success rates are now becoming a prime destination for whale watchers.
Alex Vogel also co-authored the research paper that we featured in a blog back in January, which identified the extraordinary migration of a whale from Pacific waters off Colombia to the Indian Ocean off Tanzania (ORCA | Humpback Whale Makes Record-Breaking 8,000-Mile Migration…) made possible by the HappyWhale database. This underlines the importance of the real-time and ongoing data collection that ORCA undertakes, which is substantially adding to the increased knowledge and insights being compiled by citizens scientists globally.