A week later, birdwatchers spotted a \u201conce in a lifetime event\u201d as large numbers of rarely seen albatrosses and petrels appeared off Australia\u2019s east coast, thousands of kilometres from their usual foraging grounds deep in the Southern Ocean. Many birds were in poor condition.<\/p>\n
The sightings came just weeks after a dying migratory seabird was confirmed as Australia\u2019s first case of highly pathogenic H5N1 bird flu.<\/p>\n
These sightings raise troubling questions. Seabirds and marine mammals such as whales use ocean currents and weather to travel long distances to feeding and breeding grounds. If these species are changing their behaviour, it could be a sign of altered conditions in the Southern Ocean.<\/p>\n
We know the world\u2019s oceans are running very hot. Marine heatwaves can affect any part of the ocean \u2013 even frigid Antarctic regions. If species are used to water temperatures around 2\u20136\u00b0C, a sudden boost of a couple of degrees can upend ecosystems. If the heatwave<\/a> lingers, the cumulative effect can be much bigger.<\/p>\n We don\u2019t yet know for sure, as monitoring in the Southern Ocean is limited. But we know marine heatwaves can alter currents, weather conditions and prey availability.<\/p>\n Oceans running hot<\/p>\n Since February, a large and persistent marine heatwave has affected waters around Australia\u2019s Heard Island and McDonald Islands, stretching as far south as the edge of Antarctica\u2019s sea ice. These remote islands are extraordinarily rich in life. But researchers have found their waters are exposed to damage from climate change.<\/p>\n The southern Tasman Sea has also endured a marine heatwave since at least April, likely due to the fact we are coming out of successive La Ni\u00f1as.<\/p>\n Both areas of ocean are among the fastest-warming on the planet. The steady drumbeat of climate change can make marine heatwaves more severe, more frequent and longer-lasting.<\/p>\n It\u2019s possible this marine heatwave is putting pressure on seabird and whale food supply. But there remain significant gaps in our knowledge.<\/p>\n One reason is that extreme events don\u2019t occur very often. Given this, it\u2019s worth looking at past events.<\/p>\n Devastation from \u2018the Blob\u2019<\/p>\n Between 2014 and 2016, the North Pacific Ocean was hit by an event scarier than any monster movie.<\/p>\n A huge, long-lasting and extreme marine heatwave stayed in place for many months. It became known as \u201cthe Blob\u201d.<\/p>\n Water temperatures were between 2\u00b0C and 6\u00b0C above normal. While this may not seem like a drastic change, it led to widespread ecosystem disruption. At least 240 species were found outside their normal ranges \u2013 some further north than ever recorded.<\/p>\n It\u2019s hard to overstate how extensive its effects were. Kelp forests disappeared. Millions of starfish dissolved into goo. Whales died. Seabirds starved. Toxic algal blooms appeared.<\/p>\n It\u2019s possible reported falls in whale numbers and unusual sightings of seabirds might be linked to a smaller version of the Blob in the cold Southern Ocean.<\/p>\n We already know marine heatwaves can disrupt the feeding behaviour of marine predators such as little penguins in Tasmania.<\/p>\n Our research has shown<\/a> marine heatwaves lead to significant shifts in the types of zooplankton \u2013 tiny floating animals \u2013 found in coastal seas off Tasmania. Zooplankton are important food sources for seabirds, whales and fish.<\/p>\n As early as 1997\u201398, researchers found warmer surface waters in the Southern Ocean made it harder for female Antarctic fur seals to find prey while raising their pups.<\/p>\n Deaths of pups and adults are becoming more common in the South Atlantic. The population has fallen<\/a> by around 1.5 million in the 15 years to 2022. The species was once considered abundant. But it\u2019s now has recently listed as endangered.<\/p>\n We don\u2019t know what we don\u2019t know<\/p>\n By studying past events, scientists now have a better understanding of how marine ecosystems respond to extreme events.<\/p>\n Even so, there\u2019s a lot we don\u2019t know. For example, we have strong evidence climate change is affecting Antarctic krill. But we still don\u2019t fully understand how a particular marine heatwave affects these tiny crustaceans or how ocean predators such as whales and seabirds respond during such events.<\/p>\n Mary-Anne Lea is an Adjunct Senior Research Fellow in Marine\/Polar Predator Ecology, University of Tasmania.<\/p>\n Christopher Chapman is a Senior Lecturer in Oceanography, UNSW.<\/p>\n This article was first published by The Conversation<\/a> and is republished under a Creative Commons licence. Read the original article<\/a>.<\/p>\n In short, our knowledge of how extreme events affect ecosystems isn\u2019t keeping pace with climate change.<\/p>\n For scientists to understand how vulnerable species respond to environmental triggers, we need to monitor key species over the long term, while tracking environmental conditions in breeding and foraging areas and their food sources.<\/p>\n This type of monitoring is expensive, time-consuming and challenging. It would require national coordination, international collaboration and sustained support. But if we want to understand what\u2019s driving ecosystem changes affecting local and migratory species in our waters, it will be necessary.<\/p>\n Once up and running, these dynamic monitoring systems would help authorities respond quickly by, say, reducing or redirecting fishing boats if there\u2019s a sudden drop in fish numbers. Monitoring would also show areas in need of better protection.<\/p>\n We know changes are taking place in these cold oceans. Fewer whales and rare seabird sightings are a warning sign. If we don\u2019t have better monitoring, we will keep flying blind as global warming accelerates.<\/p>\n","protected":false},"excerpt":{"rendered":"Your support helps us to tell the story From reproductive rights to climate change to Big Tech, The…\n","protected":false},"author":2,"featured_media":581777,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[26],"tags":[61,60,82,263],"class_list":["post-581776","post","type-post","status-publish","format-standard","has-post-thumbnail","category-wildlife","tag-ie","tag-ireland","tag-science","tag-wildlife"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/581776","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/comments?post=581776"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/581776\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media\/581777"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media?parent=581776"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/categories?post=581776"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/tags?post=581776"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"A](\"https:\/\/static.independent.co.uk\/2026\/07\/31\/9\/07\/Marine-heatwave.avif\")
A long-lasting marine heatwave is affecting the Southern Indian Ocean, as shown in these monthly averaged temperature anomalies. Heard Island is roughly in the centre of the image (Chris Chapman\/NOAA-OISST, CC BY-NC-ND)<\/p>\n![\"Many](\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2026\/08\/b3de5758a89cfc8626c7d510ae082208Y29udGVudHNlYXJjaGFwaSwxNzE4NzMxNDk3-2.75403551.jpg\")
Many humpback whales migrate from Antarctic waters to Australia\u2019s east and west coasts (PA)<\/p>\n