Why humane euthanasia was the only way out for the stranded

Why humane euthanasia was the only way out for the stranded

Humpback whale at Robberg Nature Reserve

A young female Humpback whale that was stranded on the Island Beach at Robberg Nature Reserve on Monday, 19 May 2025, was humanely euthanised the following morning after multiple failed rescue

attempts and a subsequent expert

assessment. The incident mobilised a swift response from the Plett Stranding Network, CapeNature, marine mammal experts, and supporting partners including the National Sea Rescue Institute (NSRI) and the South African Police Service (SAPS).

The whale appeared to have run aground on a sandbank and Robberg Nature

Reserve personnel were on site to monitor the whale and manage public access to prevent further distress or harm. The whale, estimated to be between six and seven metres in length, was likely a calf from the 2023/2024 calving season. 

“She appeared to be in good body

condition, which made her a candidate for rescue. It’s possible she became stranded due to navigational error during her

northward migration, or there may have been underlying health issues.”

Chanel Visser, Senior Marine Field Ranger

In consultation with whale scientist Dr Gwenith Penry, the NSRI, and CapeNature rangers, the decision was made to attempt a refloat. Over several hours, the team successfully guided the whale back into deeper water on several occasions.

However, the whale turned around and

re-stranded on all attempts and the team stood down just before sunset.

Though rescue teams are trained and passionate, many factors work against a successful return to the sea. The sheer size and weight of the whale is a challenge. Whales can weigh tens of tons (this one likely weighed five to six tons). Once on land, their own weight can crush their

internal organs and cause irreparable

damage. The trauma of stranding,

combined with dehydration and sun

exposure, can put the animal into shock. Even if a whale is refloated, it may strand again if it's confused, ill, or physically unable to swim effectively.

Strandings are rarely the result of one simple cause. Often, they involve a

combination of issues. A sick or injured whale may lose strength or become

disoriented, leading it into shallow water. Whales use echolocation and shallow sloping beaches like those along the

southern Cape can confuse their sonar. In some species (not Humpbacks), whales strand together out of loyalty to one another, even if only one individual is in distress. Shifts in ocean temperature, prey

movement, or even underwater noise

pollution can cause whales to enter

unfamiliar or dangerous areas.

With the whale was alive but stranded again on the morning of Tuesday, 20 May, and with public access restricted to ensure safety, the Plett Stranding Network made the difficult decision to proceed with

humane euthanasia. The operation was led by SAPS bomb squad expert Johan Ehlers, who has extensive experience in large mammal euthanasia.

“While deeply distressing, this was the kindest option to prevent further

suffering. Drug injections are not viable for whales due to their physiology. Explosives remain the most humane method.”

Chanel Visser, Senior Marine Field Ranger

The euthanasia was carried out successfully and the whale will contribute to scientific knowledge and conservation efforts.

Blubber and muscle samples have been collected for further research, and additional data will be gathered to support long-term monitoring of whale health, disease,

reproduction, and threats in the marine environment. The carcass will be towed out to deep sea for disposal within the next week.

“This incident, while heart-breaking, showed the incredible collaboration and resilience of our network. We’ve learned valuable

lessons and grown both professionally and personally.”

Chanel Visser, Senior Marine Field Ranger

CapeNature and the Plett Stranding

Network extend a word of thanks to all who contributed to the effort, including reserve staff, volunteers, marine scientists, SAPS, and the NSRI.

Press release from Cape Nature website 

Picture by: Chanel Visser