August 15th 2020 : Fatal stranding of a juvenile Humpback Whale
A juvenile Humpback Whale was stranded on the Wildside shore near Buffalo Bay on Saturday afternoon 15th August.
Confined to a rocky gully and battered by huge waves generated by a 6m swell, the whale sustained numerous lacerations.
Conditions and the location of the whale made a rescue attempt impossible and sadly it died at about 18h00.
On Sunday morning Dr Gwen Penry from the Plettenberg Marine Mammal Stranding Network and Keith Spencer from Cape Nature conducted some sampling of the whale carcass.
The whale was approximately 8.5m and the blubber was 27cm thick (indicating that it was in good condition) and there were no visible signs of injuries that could have led to the stranding.
The whale couldn’t be sexed as it was lying upright and the genital slit could not be seen to distinguish between female and male.
Cape Nature will monitor the carcass and aims to leave it in situ if possible.
How often do whale strandings occur?
While washed up whale carcasses are not uncommon along the Garden Route, the incident of live whales stranding occur less frequently. Unfortunately most whale strandings occur during stormy seas and any rescue attempt is difficult or impossible to conduct. In June 2018, 20 km east of the stranding at Wildside, another Humpback Whale died after being stranded during rough sea conditions.
While the most frequently washed up whale species in the Garden Route are Humpback Whales, we also have Pygmy Sperm Whales, Bryde’s Whales, Southern Right Whales and the occasional Sperm Whale washing up on the beaches.
- Sperm Whale washed up on Swartvlei Beach : Read Here
- Humpback Whale washed up on Swartvlei Beach : Read Here
Circle of Life
Update : Friday 21st August 2020
The pursuing rough seas and approaching spring tides succeeded in relocating the whale carcass from the rocky gully that in had originally been stranded to a section of sandy beach.
Already the natural process of bio degrading has started. While whales have a disproportionately thin skin, they have an incredibly thick layer of blubber. In the case of this juvenile Humpback Whale, it had a blubber layer of 27cm. Providing both a perfect insulation against the cold waters and energy reserves for migration, the insulation properties also accelerate decomposition of washed up whales.
The core temperature of the carcass remains high and this facilitates the rapid process of decomposition internally. The thick layer of blubber does however present a barrier to terrestrial scavengers, in particular avian species like Kelp Gulls which are not able to peck their way through to the flesh below and they have to bide their time waiting for the decomposition to create a rupture through the blubber so that they can get in.
This doesn’t prevent them from trying, and on Friday, 30 Kelp Gulls had gathered on the carcass, pitting the skin with ineffective pecks and streaking the carcass with their droppings.
From the tail section a large sample of blubber and muscle tissue had been removed by researchers which has allowed the gulls to begin feasting on the whale.
The current course of action with the carcass is to leave it in situ as long as possible. This is going to provide a valuable study to determine how the decomposing whale enriches the surrounding region.
Similar studies have shown that the invertebrate fauna, the agents of mechanical breakdown of a carcass, increase in population size. In turn they become a prey resource for a variety of micro and medium sized predators, which ultimately become a food source for larger predators.
The duration of the study will ultimately rely on public understanding of the relevance of such a study as well as their tolerance for a the by product of decay of a carcass. The second mechanism of decomposition is considered chemical and micro organisms breakdown the soft tissues. The by product is as usual a strong odor and the usual petition for the carcass to be removed.
How long can a carcass remain in left to nature? Having observed various whale carcasses in remote locations, they are typically removed naturally within 6 to 8 weeks by subsequent tides. That can shift along the shoreline by up to 2km, but they generally fragment with only reduced sections of blubber and sections of the skeleton remaining.
Most skeletal parts do get carried off for research and as souvenirs, but there are still a few ribs wedged into rocky sections over five years after a whale has washed ashore.
Melting in the Sun.
One of the interesting processes of the decomposition of a whale carcass to watch is the ‘melting’ of the blubber. Probably best to observe between midday and mid afternoon, the radiation from the sun heats up the blubber which then liquefies and trickles down the carcass to the beach. This blubber, on rocks, can stain them white. The adult male Humpack Whale which washed at Gericke’s Point in October 2013 left a blubber stain, which even now in 2020 is decernible, though very faded.
On the beach, the whale oil peculates into the sand and fuels an entire colony of micro marine invertebrates, though the perpetually shifting sand and tides wash it away within a few weeks.
Natural Selection :
While every attempt to rescue stranded whales is made after discerning evaluation, it is crucial to remember that death is a natural process and we can expect some whales to wash ashore.
Every stranded and washed up whale is studied to determine what the cause of the stranding is , and in the event of a washed up whale, what the cause of the death was. Plastic and chemical pollution are rapidly becoming a factor which is causing whale deaths as they ingest plastic which then blocks their digestive tract. Read More
What to do if you encounter a stranded whale in the Garden Route.
If you encounter a stranded whale in the Garden Route the first action required is to contact the legally designated authority so that the best assessment can be made on how to deal with the situation.
Stranding Organisations to contact :
- Between Mossel May and Sedgefield : SMART (072 227 4715),
- Betwenn Sedgefield and Port Elizabeth : Plett Marine Mammal Stranding Network (079 463 4837),
- PE Museum ( 072 679 4643)
- Cape Nature (064 608 9270),
- SANParks (084 714 7793),
- Strandloper Project (082 213 5931),
- Natures Valley Trust (084 549 8498).
For other strandings : Read Here