Unusual strandings of bronze whaler sharks in Eastern Cape leave scientists puzzled
Shark researchers and scientists are trying to understand why there have been mass strandings of bronze whaler sharks along the Eastern Cape coastline.
A pregnant bronze whaler shark carrying 11 pups was stranded at Winterstrand in East London on Saturday.
Since late March, scientists have been left puzzled by the mysterious stranding of 44 bronze whaler sharks along the eastern and southern coastline.
Inspections by researchers have so far shown the marine animals had no injuries or any signs of physical trauma.
The pregnant shark with 11 pups was one of three located within a few hundred metres of each other in Winterstrand on Saturday. The three included one male.
Retired marine biologist Dr Malcolm Smale said:
It’s very unusual, I have never seen such a large number of sharks beaching in my 40 years of experience working with these animals in this area before.
“This is one of the most baffling fish challenges to present itself in a long while,” said East London Museum scientist Kevin Cole.
KwaZulu-Natal Sharks Board scientist Dr Matt Dicken said there had been 44 shark beachings in the Eastern Cape over the past few months.
Unusual strandings of bronze whaler sharks in Eastern Cape leave scientists puzzled
Smale said researchers on the southern and eastern coast were still working together to establish the cause of the strandings.
He warned members of the public not to not touch the sharks, but rather report sightings to authorities.
“We are not sure of the cause, but it would be unwise to eat the sharks in case they have some kind of toxin in their bodies. I am sure that more information and advice will come out once the cause is established.”
Cole said the strandings had started in late March this year and did not seem to be related to recreational fishing or predation.
The record shows that whatever the cause of death, it seems to be quite species-specific, mostly to the bronze whalers (Carcharhinus brachyurus).
In the East London area alone, there had been six mortalities of bronze whalers. Of those, five were female and one a male, added Cole.
He said two of the five females had been heavily pregnant, and that one had given birth to 15 pups near Glengariff.
“There have also been two reports in our area of erratic shark behaviour close to river mouths before the strandings, and in one instance filmed at the Balugha River mouth. None of the strandings which I have investigated have shown any signs of physical trauma to the animals such as bite marks or any other,” added Cole.
Data is being collated by Dr Greg Hofmeyr of Bayworld, Dicken, and Smale.
Members of the public are requested to report any shark strandings to the Bayworld and East London museums.
Source:
- Bumblebee population increases 116 times over in ‘remarkable’ Scotland rewilding project
- Killer whales have found new homes in the Arctic Ocean, potentially reshaping marine ecology
- First Klamath River salmon since 1912 reported in Oregon after dam removal!
- VANISHING VOICES: Saving Our Hawaiian Forest Birds
- Coral Restoration’s Wake Up Call
- Why air pollution bamboozles pollinating bees
