What was thought to be a whale entanglement situation in Algoa Bay has turned out to be something much more unusual.
National Sea Rescue Institute (NSRI) veteran and former station commander Ian Gray said on Monday the organisation had deployed two boats after an alert from eco-excursion group Raggy Charters and drone footage which seemed to indicate an entangled humpback whale calf being dragged through the water, possibly by its similarly ensnared mother.
He said the NSRI boats had raced out to the scene, about 11km from the Port of Port Elizabeth, south of St Croix Island, and they were able to get close enough to confirm what was going on.
"We were pleased to see that there was in fact no entanglement of either the calf or the mother — but there was something not quite right with the calf.
"Its mouth was constantly gaping, giving the impression the rope was tangled between its jaws and it was being towed through the water.
"But there was no rope.
"It's the first time we've ever seen anything like that, and it seems it's a first nationally, as we passed on our information and photographs to the SA Whale Disentanglement Network."
He said there was no sign the whale calf had been hit by a ship.
"The thinking is it's a genetic abnormality or another injury of some kind."
Gray said now that the whale calf with its strange affliction was on record, the NSRI and other members of the disentanglement network would be looking out for it, to see how well it was surviving.
"Whatever the case, this has been another example of the brilliant eyes on the sea that Raggy Charters provides."
Bayworld-based marine biologist Dr Greg Hofmeyr said on Monday there was something clearly wrong with the calf, and it seemed to be a fairly recent injury.
"It's obviously unable to close its mouth properly, and that's why it's staying on the surface.
"It seems likely it was not born with this problem because it is swimming strongly, so it is in reasonably good health.
"That means it was able to suckle, which would have necessitated it going underwater and closing its mouth."
Mature humpback whales use their sieve-like baleen to feed on plankton, small fish and tiny shrimps called krill.
Hofmeyr said it was not clear how the calf would fare going forward.
"The Bayworld Stranding Network will be on stand-by in case it becomes weak and then gets washed ashore."
The Bayworld Stranding Hotline number is 071-724-2122.