Rare Fin Whale Stranding Recorded Along Greater Dyer Island Coast

The Marine Dynamics and Dyer Island Conservation Trust (DICT) teams were alerted on Wednesday, 1 July, by Jason Stafford of Ivanhoe Sea Safaris, who reported a deceased whale close to Gansbaai Harbour. The whale later washed up at Die Plaat, and our team immediately responded to assess the animal and begin documenting the stranding.

Upon arrival, the team confirmed that the whale was a female fin whale (Balaenoptera physalus) of 23 metres, the second-largest whale species on Earth after the blue whale. Fin whales are large baleen whales found in oceans across both the Northern and Southern Hemispheres, generally inhabiting offshore and deep-water environments. However, they do move through productive temperate and cooler waters in search of food. They are sleek, fast-moving whales that can reach up to 27 metres in length and weigh more than 70 tonnes (70,000 kilograms). The species is currently listed as Vulnerable on the IUCN Red List following severe global declines caused by industrial whaling.

The whale was identified as a fin whale based on several distinguishing features observed by the Dyer Island Conservation Trust research team. These included the asymmetrical colouring of the baleen, with only the first few baleen plates on the left side showing white outer edges, while on the right side the first 100–200 plates are white to pale in colour. Fin whales can also be identified by their ventral grooves, which may extend as far as the umbilicus, as well as the amount of white visible along the right side of the throat and tail region. Together, these features helped DICT scientists confirm that the stranded whale was a female fin whale. Fin whales are known for this striking asymmetry in pigmentation, particularly on the head and baleen.

According to Wilfred Chivell, Founder of the DICT and CEO of Marine Dynamics Eco Tours, this is the first time he has ever seen a fin whale stranded along the Greater Dyer Island area coast.

The team will return to the site again today, together with scientists from the University of Pretoria Whale Unit (based in Hermanus), to continue research and data collection in an effort to better understand the circumstances surrounding the stranding.