<div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>After six orcas were filmed viciously killing a great white shark off </span><a href="https://www.9news.com.au/south-australia" rel="" target="_blank" title="South Australia"><span>South Australia</span></a><span>'s Neptune Islands in 2015, </span><a href="https://www.9news.com.au/sharks" rel="" target="_blank" title="sharks "><span>sharks</span></a><span> disappeared from the waters for over two months.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>Their abnormally long absence was attributed to the incident, as a study in </span><a href="https://www.9news.com.au/south-africa" rel="" target="_blank" title="South Africa"><span>South Africa</span></a><span> suggested similar instances along their coast caused sharks to abandon their habitat. </span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>But now, new 12-year research in Australia has debunked that theory.</span></div></div><div><div id="adspot-mobile-medium"></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><strong><span>READ MORE: </span></strong><a href="https://www.9news.com.au/national/shark-in-antarctica-australian-researchers-capture-vision-of-shark-in-nearfreezing-water/e5f08f17-bae7-411f-a180-61bdedf0cb0f" rel="" target="_blank" title=""><strong><span>Aussie researchers capture 'significant' vision of shark in near-freezing water</span></strong></a></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>Dr Isabella Reeves, a postdoctoral researcher from Flinders University, led the study and said her team identified six instances when sharks left the Neptune Islands for weeks at a time.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>"These were more than 42 days, and only one of them had this killer whale predation, which was the event we had in 2015," she said. </span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><h3><strong><span>The encounter that started it all</span></strong></h3></div></div><div><div class="OUTBRAIN" data-reactroot="" data-src="//www.9news.com.au/national/new-study-debunks-theory-on-why-sharks-fled-aussie-islands-after-vicious-orca-attack/3582d90d-9837-4a2b-864d-519902658e20" data-widget-id="AR_5"></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>A cage diving company based in Port Lincoln took a group out to get up close with sharks at the Neptune Islands on February 2, 2015.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>But just 20 metres from their vessel, they witnessed six orcas going in for the kill.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>Three orcas appeared to fence in a shark, while the others rammed it with their heads.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>They pushed the shark underwater and an oil slick appeared on the surface, indicating the liver had been consumed.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>The footage of the encounter went viral and gained national interest.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>Reeves said it was considered very rare at the time but has been recorded more over the years, particularly in Australia, South Africa, California and Mexico. </span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>"The fact that killer whales had rocked up to the Neptunes, which is a really small island group that's offshore, and someone was there to actually document it, it was a really rare opportunity to try to dissect the situation more once we had gotten more data over the years," she said.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><strong><span>READ MORE: </span></strong><a href="https://www.9news.com.au/finance/unemployment-australia-january-data-abs/d9e145b1-58a7-4eb6-8da1-d20f2c5ec03a" rel="" target="_blank" title=""><strong><span>50,000 Aussies just got a new job - but there could be an unwelcome flow-on effect</span></strong></a></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><h3><strong><span>Sharks disappear from Neptune Islands</span></strong></h3></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>Sharks disappeared from the waters in the Neptune Islands for the next 69 days after the orca attack.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>Andrew Fox from Rodney Fox Shark Expeditions said he saw an increase in sharks at the Neptunes from the early 2000s, but that changed in 2015.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>"It's been very much more patchy since then, and in the last two years, it's been really slow," he said. </span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>"It seems like there's a lot more than there is, but I'm worried that there has been a bit of a slow decline, and we're certainly seeing a lot less in the last two years than we've ever seen."</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>There have also been environmental changes in recent years, including record oceanic upwellings and a toxic algal bloom. </span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>Fox has only seen orcas at the Neptune Islands a handful of times in his 50 years in the business.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>"We had a really big Orca, a big male with an extremely tall dorsal fin, come up to the back of our vessel and smash its tail up and down repetitively and scare away a big white shark we knew, a formidable, five-metre male we know as Dragon," he said.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>"We haven't seen Dragon since, so I'm a bit worried about what happened to him. But other white sharks did come back a week and a half or 10 days later."</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><strong><span>READ MORE: </span></strong><a href="https://www.9news.com.au/national/the-super-mistake-which-could-cost-young-aussies-128000/d66a4595-f0a7-4076-8f7a-1a04f06af272" rel="" target="_blank" title=""><strong><span>The super mistake which could cost young Aussies $128,000</span></strong></a></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><h3><strong><span>Twelve years of research</span></strong></h3></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>The research team used acoustic telemetry data, based on listening stations that ping once a tagged shark is near, and sightings from tourism companies to track sharks over 12 years to understand whether the 2015 absence was exceptional or behavioural.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>They identified six instances of prolonged absences, including a brief five-day departure during an orca sighting in October 2024 and a four-day absence during the death of a tagged whale.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>But they found that not every orca encounter or shark death led to these absences.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>Reeves said movement patterns of great white sharks in the Neptune Islands were highly variable. </span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>"There's definitely long gaps in their presence, which can happen with or without killer whale activity," she said.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>"It's really hard to say. There's so much going on in our oceans right now, which could be contributing to this.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>"But I think the main takeaway is that it's not the killer whales at the Neptunes that are causing the prolonged absences."</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><span>Another study is currently under way to understand what causes prolonged shark absences.</span></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><strong><em><span>NEVER MISS A STORY:</span></em></strong><span> </span><em><span>Get your breaking news and exclusive stories first by following us across all platforms.</span></em></div></div><div class="block-content"><div class="styles__Container-sc-1ylecsg-0 goULFa"><ul><li><strong><em><span>Download the 9NEWS App here via</span></em></strong><span> </span><a href="https://apps.apple.com/au/app/9news/id1010533727" target="_blank"><strong><em><span>Apple</span></em></strong></a><span> </span><strong><em><span>and</span></em></strong><span> </span><a href="https://play.google.com/store/apps/details?id=nineNewsAlerts.nine.com&amp;hl=en_AU&amp;pli=1" target="_blank"><strong><em><span>Google Play</span></em></strong></a></li><li><strong><em><span>Make 9News your preferred source on Google by</span></em></strong><span> </span><a href="https://9.nine.com.au/8x987w" target="_blank"><strong><em><span>ticking this box here</span></em></strong></a></li><li><strong><em><span>Sign up to</span></em></strong><span> </span><a href="https://login.nine.com.au/edm?client_id=nineatnine" target="_blank"><strong><em><span>our breaking newsletter here</span></em></strong></a></li></ul></div></div>