A whale calf, closely followed by its mother, came within metres of surfers and swimmers at Manly beach, in Sydney’s north, on Sunday afternoon.
The pair were initially identified as humpbacks by onlookers, but marine wildlife experts later said they were most likely southern rights, which also migrate north to calve, then return to colder waters for the southern summer.
One boardrider, Josh, told Guardian Australia he had never seen a whale, particularly a calf, come so close to the beach at Manly.
“There was a bit of pointing going on and I looked round and the little one was just there,” Josh said.
“Then mum came in pretty quick smart, I think when she realised how close people were.
“You often see [whales] further out the back but this one just came right up to where people were hanging on their boards.”
Images show dozens of surfers watching from about 10m from the whales.
Initially there was some concern that one of the whales had been caught in a shark net, but surfers said that was not the case.
“I think everyone was just paddling up to get a good look. It’s the sort of thing you won’t forget seeing.”
Last week researchers from the University of NSW found that while whale-watching season in Australia is often a tourism drawcard, many were not in optimum health during the return leg of the migration.
The researchers collected and analysed samples of whale blow – similar to mucus from a human nose – from humpbacks and found “significantly less” microbial diversity and richness on journey south.
Their paper, published in the journal Scientific Reports, said this indicated the whales were likely in poorer health than when their journey began.
“People enjoy whale-watching season, but with it comes reports of whales becoming stranded,” said the study’s lead author, science researcher Catharina Vendl.
“Although humpback whale stranding events occur naturally and regularly to injured and young whales, it is crucial to monitor the population health of this iconic species to ensure its long-term survival.
“Humpback whales do not only play an essential role in their marine ecosystem but also represent an important economic resource because whale-watching is a booming industry in many Australian cities and around the world.”
• This article was amended on 3 August 2020 to correct the identification of the species. It originally said the whales were humpbacks, but marine wildlife experts contacted by Guardian Australia subsequently identified them as more likely to be southern right whales.