Latest news with #VanessaPirotta
The Guardian
3 days ago
- Science
- The Guardian
Winter brings Australia's ‘humpback highway' to life and peak hour is about to begin
Every winter, Australia's 'humpback highway' hums to life. Thousands of humpback whales migrate from Antarctic feeding grounds to tropical breeding areas along Australia's east and west coasts. Dr Vanessa Pirotta, a Sydney-based whale scientist, said that peak 'blubber to blubber' traffic on the highway occurs between mid-June and early July. That is when crowds will flock to greater Sydney's headlands and beaches, hoping to glimpse the balletic performers as they defy their immense size. Lucky spotters can watch whales, weighing up to 40 tonnes, breach and crash back into the Pacific Ocean, flanked by bursts of sea spray. 'You don't need a boat to see a whale,' Pirotta said. 'I would encourage Sydneysiders to look out on their weekend or morning walk because we have such a fabulous coastline. 'Anywhere you can see the ocean, you have a chance of spotting a whale.' Once hunted to near extinction, the humpback whales – Megaptera novaeangliae – have made a remarkable recovery. Population estimates now range between 30,000 and 50,000. Sign up for Guardian Australia's breaking news email But as numbers grow, migration patterns are shifting. 'Some are hanging out here all year round, at least in those colder southern waters like Tasmania,' Pirotta said. Global heating, shifting food sources and warming oceans are likely factors – with implications for future marine life. No longer listed as a threatened species, humpbacks still face risks in increasingly industrialised seas. Entanglement in commercial fishing gear, shark nets and drum lines, vessel strikes and acoustic pollution from seismic blasting are all potentially deadly hazards. Last year, it took rescuers almost five hours to free a young humpback whale in Sydney Harbour after it became entangled in ropes and buoys. 'When you're a migrating animal the size of a bus, there are a number of challenges that whales face that we as humans present,' Pirotta said. The growing humpback population means conservation efforts 'need to be bumped up', she said. Melting Antarctic ice is also threatening krill – a key food source for the whales, which are so important to supporting ocean health. 'Their poo drives nutrients and helps the food chain, which we rely on, especially our fisheries industry,' Pirotta said. Pirotta works with the Gamay Rangers, who care for country around Gamay (Botany Bay). 'Indigenous knowledge holders reflect the past of our First Nations scientists, our first whale scientists,' she said. For many saltwater people of the east and west coasts, whales are sacred and hold a significant cultural and spiritual place. Yuin man Dr Jack Pascoe, an ecologist at the University of Melbourne, said the whales – Gurawal – hold lore in the form of stories. Pascoe helped establish the Saltwater People's Alliance, which advocates for the preservation of whale song lines. He said Australian environmental laws are 'flawed and not fit for purpose'. Stronger action on climate and more Indigenous-led conservation strategies that recognise species of cultural significance were needed, he said. Simon Miller, from the Australian Marine Conservation Society, has said the 'pressing international threat' of climate change is affecting whale migration and marine ecosystems. 'Australia needs to be a leading global citizen and do our bit … keeping global warming to 1.5 degrees,' Miller said. Like Pascoe, he has urged state and federal governments to develop stronger environmental policies. According to the CSIRO, sea surface temperatures in Australia have risen by 1.08C since 1900, with the greatest warming off the south-east and Tasmania.
BBC News
13-05-2025
- Science
- BBC News
South Australia fish kill: Toxic algae poisons 200 marine species
More than 200 marine species off the coast of South Australia (SA) have been killed by a weeks-long toxic algae explosion, in what conservationists have described as "a horror movie for fish".The algal bloom - a rapid increase in the population of algae in water systems - has been spreading since March, growing to about 4,500 sq km (3,400 sq miles), or roughly the size of nearby Kangaroo Island."It's an unprecedented event, because the bloom has continued to build and build," said Vanessa Pirotta, a wildlife scientists say the algae produces poisons which "act like a toxic blanket that suffocates" a wide range of marine life, including fish, rays and sharks. Brad Martin, SA project manager for OzFish, a non-profit organisation that protects fishing habitats, said that while algal blooms are not uncommon, the "massive" scale of the current event has had a dramatic impact on marine produced by the algae can cause "gill and tissue damage" by attacking the red blood cells, Mr Martin told the large density of the bloom also means that oxygen is being taken out of the water, "so we know that the fish are suffocating"."It is like a horror movie for fish," he event has been widely documented by people sending in pictures of dead wildlife washed up on beaches. The effect on sharks and rays has been particularly graphic, with large numbers washing up on beaches "bright red", showing indications of haemorrhaging.A three-metre great white shark was among those found dead in recent weeks. Among the more than 200 species that have been killed, which range from the smallest of baby fish to great whites, some are more vulnerable than others. Reef species like crabs and pufferfishes have been the worst hit, as they are less mobile and can't swim away from the toxic the algae isn't harmful to humans, those exposed to high doses can experience skin irritation and respiratory symptoms such as coughing or breathing SA government has advised people to avoid swimming at beaches where there is discoloured water and blooms occur during sunny and warm conditions, and SA has had a marine heatwave since last September, with temperatures about 2.5 degrees warmer than has also been experiencing unseasonably warm conditions since March, which has further driven the size and duration of the current algal last time SA recorded a large event of this type of toxic algae was in 2014, according to the state's environment and water spread has also affected some commercial fisheries, which have pre-emptively closed harvest coastal businesses have also seen a dip in visitors due to the sheer number of dead marine life washing up on shore. Meanwhile, researchers and the SA government are continuing to monitor the bloom as it moves west.
Miami Herald
30-01-2025
- Miami Herald
‘Majestic' ocean creature makes surprise appearance off Australia. ‘Unforgettable'
Ferry-goers and passers-by on the coast of Australia were in for a special surprise when a gray ocean creature made its way close to shore. A fin popped out of the water followed by a head and blow of air as a small whale appeared in the coastal water, according to a video posted Jan. 26 by Cronulla & National Park Ferry Cruises. A chorus of excitement is heard in the background of the video as the whale cruises around. 'A beautiful (minke) whale was spotted near Bundeena Wharf today, giving passengers on the Cronulla Ferries an unforgettable experience,' the company said on Facebook. 'These majestic creatures are such a special sight in the area, and we're lucky to witness such a close encounter with nature.' The company identified the animal as a minke whale, some of which are commonly spotted in places off the Great Barrier Reef and other warm waters in the southern hemisphere. But when biologists took a look at the video, they said the whale was actually something much more rare — a juvenile Antarctic minke whale. 'I've never heard of an Antarctic minke whale here,' wildlife scientist Vanessa Pirotta told The Guardian. 'It's a species that we don't generally see off Sydney, regardless of time of the year.' Unlike the common minke whale, Antarctic minkes don't have white markings on their flippers, and they are some of the smallest whales in their family which includes blue whales, according to the Whale and Dolphin Conservation. They typically don't reach lengths of more than 30 feet long, dwarves compared to their giant cousins. Why this Antarctic minke whale was so far from home, and seemingly alone, is a mystery. 'It may be a case of mis-navigation, it may be a case that it just happened to be in the area,' Pirotta told The Guardian. 'The thing is it looks in good condition, and it was observed going out to [sea], which is a good thing. If we'll see it again, I'm not sure.' Bundeena Wharf is on the south side of Sydney, Australia on the country's southeastern coast.
The Guardian
27-01-2025
- Science
- The Guardian
Antarctic minke whale swims alongside passenger ferry near Sydney
The whale was seen following the boat as it approached Bundeena wharf on Monday, a sighting the ferry company manager, Christine Hack, called 'very rare'. Dr Vanessa Pirotta, a wildlife scientist at Macquarie University, said she and other experts had identified the creature as likely to be a juvenile Antarctic minke whale, and that spotting one in Sydney's warm waters was very unusual
