The contents of a container stored in a laboratory at the City University of Hong Kong campus in Kowloon Tong are nothing special. There’s a plastic wrapping from a yogurt drink, a water bottle label, fish bait packaging and a surgical glove. What’s of interest is that the collection was found in the oesophagus, stomach and intestine of a juvenile green sea turtle ( Chelonia mydas ) that was discovered washed up on Sham Tseng beach, Tsuen Wan, on October 13 as Typhoon Nangka swept past the city. “These were also found inside the turtle,” says Brian Kot Chin-wing, holding up specimen jars containing fishing line and rusty fishing hooks. Kot is visiting assistant professor in the Department of Veterinary Clinical Sciences and researcher in the State Key Laboratory of Marine Pollution at the university. He and his team were shocked because it was the second green sea turtle – a protected species in Hong Kong and listed as endangered under the International Union for the Conservation of Nature Red List of Threatened Species – handed to the research team last month. A few days before Nangka hit, the badly decomposed body of a young female was discovered at Tung Wan Beach on the east side of Cheung Chau Island. It too had ingested plastic. Seas around Hong Kong are swamped in microplastics “The impact of marine plastic debris on the ecology and the outlook of sea turtles is enormous,” says Kot. A radiographer, he has taken diagnostic imaging used on humans into the veterinary field, using virtopsy – a virtual alternative to a traditional autopsy, conducted with scanning and imaging technology – to investigate a marine animal’s biological health, injuries and cause of death. Since 2014, postmortems on whales and dolphins stranded in Hong Kong – 208 out of 271 cetaceans found – have been examined using virtopsy at the Aquatic Animal Virtopsy Lab, where Kot is principal investigator. Now the technology is being used on sea turtles. In a room at CityU, 3D images of one of the turtles found last month are projected onto a screen. Kot explains that the technology is a less intrusive and healthier way to analyse living and dead organic matter. “We use diagnostic imaging and 3D reconstruction technology instead of cutting through flesh and bone. Stranding response personnel are understandably reluctant to dissect carcasses, not just because they are decomposed and smelly but for fear of zoonotic potential,” he says, referring to when a disease jumps from a non-human to a human. Kot says timing is crucial when retrieving stranded carcasses – and members of the public on the ground play a vital role. “If citizens spot aquatic animals they can contact the AFCD [Agriculture, Fisheries and Conservation Department] by calling 1823 or contact our team via Facebook, and we can help to report the case to AFCD … The quicker a carcass is collected, the quicker a virtopsy and tissue sampling can be carried out to investigate the potential cause of death,” he says. In past clean-ups, the waste in these remote coves would have been collected by swimmers and loaded into kayaks, but the swell is too strong today so team members have to climb the four-metre cliffs and move the rubbish using ropes and pulleys Esther Roling, co-organiser of the Adventure Clean-up Challenge Kot says that the death of marine creature from man-made causes, such as being hit by boats and becoming entangled in discarded fishing nets, is a major problem. Marine debris, he says, played a role in the deaths of the two turtles. “Eating plastic debris leads to blockages in their guts, which leads to gastrointestinal ulceration and perforation and, ultimately, a slow death. In the water, a surgical glove looks and moves like a jellyfish, so the turtle would have mistaken it for food,” he says. Sea turtle numbers are dropping globally due to pollution, plastic and trash in their egg-laying areas , including in Hong Kong, which once had a healthy turtle population. A 2019 study carried out by Greenpeace East Asia and Education University found the seas around Hong Kong were swamped in microplastics , the city’s obsession with unnecessary packaging having contributed to an 11-fold increase in pollution in three years. Combating marine pollution has become a massive task in Hong Kong, one that is increasingly being tackled at a grass-roots level. It’s the last day of October and the Chung Yeung Festival, and people have gathered near Big Wave Bay on the south side of Hong Kong Island for the last day of the Adventure Clean-up Challenge. They are among the 13 teams of swimmers, kayakers, climbers, trail runners and hikers who cleared several tonnes of trash from difficult-to-reach areas along Hong Kong’s coastline that are off the radar of government waste-collection services and other organised beach clean-ups. View this post on Instagram A post shared by Adventure Clean Up Challenge (@adventurecleanup) Event co-organiser Esther Roling clambers with ease along the rocky coastline that is lined with bags of rubbish. In 2017, Roling and husband, Paul Niel, embarked on a coasteering tour of the 80km coastline of Hong Kong Island. During their six-day adventure they encountered huge amounts of pollution, and photo logged 163 trash sites that they made public on www.pollutionmaphk.com . The adventure was turned into a documentary, The Loop . “In past clean-ups, the waste in these remote coves would have been collected by swimmers and loaded into kayaks, but the swell is too strong today so team members have to climb the four-metre cliffs and move the rubbish using ropes and pulleys,” Roling says. Bertha Shum, founder of Earthero Project, a creative solutions company that helps businesses develop environmental initiatives, is one of the volunteers. “Yesterday, this stream wasn’t flowing because of all the styrofoam and other plastic that had collected in the pool and along the edges, but today it’s back to normal,” she says.