Some of Robert Irwin's fans were alarmed on Sunday when he shared a photo to Instagram of himself swimming with a giant manta ray. Several expressed concerns for the 17-year-old's safety, noting how the scene at first glance looked eerily reminiscent of how his father, Steve Irwin, was killed. Steve died in September 2006 at the age of 44 after being stabbed through the chest by a stingray barb while filming a documentary on the Great Barrier Reef. Scroll down for video Bad memories? Some of Robert Irwin's fans were alarmed on Sunday when he shared this photo to Instagram of himself swimming with a giant manta ray Robert revealed he was filming in the same area for an upcoming Shark Week TV special, sharing additional photos and videos on Instagram. 'Sunday July 11 at 8pm I get the honour of kicking off shark week on @discovery in the USA with "Crikey! It's Shark Week",' the conservationist captioned the post. 'For the first leg of this epic adventure, I'll travel to the spectacular Great Barrier Reef as a warm up before I go face to face with great white sharks at the Neptune Islands. Sad loss: Several expressed concerns for the 17-year-old's safety, noting how the scene at first glance looked eerily reminiscent of how his father, Steve Irwin, was killed Outdoor office: Robert revealed he was filming on the Great Barrier Reef for an upcoming Shark Week TV special, sharing additional photos and videos on Instagram 'From night diving with sharks on the hunt, to getting one-on-one with massive manta rays, it was a great way to start this expedition!' But many nervous fans urged Robert to 'please be careful' - despite the fact manta rays don't have barbs and aren't harmful to humans like stingrays. 'I did not realise I had PTSD until this moment. Please be careful,' one person wrote, while another commented: 'You stay the f**k away from them rays alright'. Exploring: 'From night diving with sharks on the hunt, to getting one-on-one with massive manta rays, it was a great way to start this expedition!' he wrote on Instagram Take care: Many nervous fans urged Robert to 'please be careful', despite the fact manta rays don't have barbs and aren't harmful to humans like stingrays 'Please, please and I know everyone has told you... and I know you are very trained... please, please be careful. We don't want to lose you… a very gifted and talented young man,' added another. 'Seeing that pic of you and the stingray brings back horrific memories of what happened to your legend father,' commented one fan. One person claimed 'this pic made me shiver', while another urged Robert to 'be extra careful around the pointy end of those things'. Tragedy: Steve died in September 2006 at the age of 44 after being stabbed through the chest by a stingray barb while filming on the Great Barrier Reef 'Seeing that pic of you and the stingray brings back horrific memories of what happened to your legend father,' commented one fan Voicing their concerns: One person claimed 'this pic made me shiver', while another implored him to 'be extra careful around the pointy end of those things' In a September 2018 interview with Larry King Now, Robert and his sister, Bindi, said they had no animosity towards stingrays after their father's death. 'I don't [have any bitterness towards stingrays]. Honestly, I really don't. Because it was just a crazy accident that happened,' Bindi, 22, said. 'And stingrays are really beautiful animals. Dad loved them, we love them, and they're important to our environment. And I know that dad would be the first person to say, "I love stingrays."' Making amends: In a September 2018 interview with Larry King Now , both Robert and his sister, Bindi, said they had no animosity towards stingrays after their father's death All rights reserved for this news site (dailymail) and under his responsibility