A rare wanderer from the polar south has surfaced in Port Elizabeth. He is only the third specimen of his kind ever recorded on SA’s shores and he may have travelled as much as 8,000km to get here.
The Antarctic fur seal is being rehabilitated at Bayworld after stranding in Herold’s Bay near Mossel Bay earlier in September.
It was emaciated and would have died but was rescued by the local Stranded Marine Animal Rescue Team and shuttled to Port Elizabeth, stranding coordinator Dr Greg Hofmeyr said this week.
Hofmeyr, who is a marine biologist and seal specialist based at Bayworld, said Antarctic fur seals spent most of their lives in the open ocean, hauling out only now and then on the islands of the Sub-Antarctic.
It was possible that Herold, as it had been dubbed, had come from the colonies on Bouvetøya, or even Marion island, which is a mere 2,000km from Cape Town.
“But 95% of the total population of six million Antarctic fur seals lives on the island of South Georgia in the South Atlantic, east of the southern tip of Argentina, so it’s quite likely he came from there.”
In a direct line, South Georgia is 5,300km away. But a satellite tag on an Antarctic fur seal nicknamed Bear, rehabilitated at Durban’s Seaworld and released in 2016 off Algoa Bay, showed that inclusive of meanders and hunting forays the animal swam 8,000km to get back home.
Hofmeyr said Herold had been initially treated with rehydration fluids and fed fish gruel and vitamin additives but was now taking solid fish.
“He’s not too sure about taking dead fish that don’t move – which is in line with the SubAntarctic fur seals we’ve rehabilitated, while the Cape furs catch on much more quickly.
“We also don’t have any benchmarks for his species to monitor his recovery, but he is slowly improving.”
Hofmeyr said it was not clear why the animal had wandered so far but it was possible that, as a youngster, it had been exploring and had then become confused.
In its home waters the Antarctic fur seal preys on shrimplike krill, squid and fish, especially lantern fish. Any change in prey species could confuse the hunter, he said.
The only other Antarctic fur strandings on the SA coast were recorded in 2016 and in July this year. While Bear recovered well, the second specimen died within a couple of days.
Hofmeyr said it was not clear why the species had suddenly started stranding.
“Possibly people were not properly identifying it before but also possibly it might relate to climate change and a shift in the range of their prey.”
Targeted for their particularly thick fur coats, Antarctic fur seals were hunted almost to extinction from the late 1700s and through the 1800s. By 1910 they appeared to have been wiped out – but then three small surviving colonies were found on South Georgia, Bouvetøya and Îles Kerguelen.
Ironically, they bounced back because baleen whales, their main competition for krill, were themselves being drastically reduced by the whaling industry.
With the 1986 ban on whaling and subsequent resurrection of baleen whale numbers, the competition had returned, Hofmeyr said.
Two Sub-Antarctic fur seals that are also being rehabilitated at Bayworld should be ready for release about the end of October. They would be ferried out to the best release zone about 70km off Cape Recife, Hofmeyr said.
“The Agulhas Bank from there starts extending out, deflecting the Agulhas Current south. It’s a marine conveyor belt directly to the area the seals need to go.”
Hofmeyr said the aim was to attach satellite tags to the animals to allow for tracking.
Anyone able to sponsor the tags – which cost R16,000 each – should call the stranding hotline 071-724-2122, he said.
Strandings could also be reported via this number.