Virtopsy – new ways of looking at marine mammals
By : Michael Gibb
Even if you’ve never heard of virtopsy, you can guess the meaning. Essentially it involves the application of forensic radiology with the use of computed tomography, magnetic resonance imaging, ultrasonography, optical 3D surface scanning and 3D photogrammetry to study both living and deceased organic matter without having to cut through flesh and bone.
Fortunately for CityU, one of our young researchers is rapidly establishing a reputation in the field of virtopsy for cetaceans. Dr Brian Kot Chin-wing, Visiting Assistant Professor in the Department of Infectious Diseases and Public Health and Research Fellow in the State Key Laboratory of Marine Pollution, has set up a global database for factors related to marine mammals such as whales and dolphins that get stranded.
“We are the first team to conduct virtopsy and look into postmortem radiographic images of dead marine mammals in Hong Kong and adjacent waters, as well as from our collaborators around the world, examining factors such as cause of death, wounds and injuries and establishing a biological profile of those cetaceans,” says Dr Kot, who joined CityU in October 2018.
A leap of faith
How CityU commenced its activities in this extremely new area of using virtopsy for stranded cetaceans involved a fair amount of serendipity.
“We found ways to reduce the costs of analysing the carcasses and producing a lot of useful data for identifying species, animal health prior to death and the possible causes of death.”Firstly, Dr Kot is unique. He is one of the few trained diagnostic radiographers who has moved into the world of veterinary studies. He focused on the use of diagnostic imaging for pathological investigation in human medicine as an undergraduate, but at the same time harboured a love of dolphins.
“Through my PhD studies, I could see that diagnostic imaging would work well with marine mammals. For instance, when working with live dolphins, taking frequent blood samples is not very practical whereas conducting an ultrasound is much more convenient,” he says. “My ideas for virtopsy began to take shape and I looked around for areas related to marine mammals like dolphins where I could apply my skills in radiography.”
Setting up protocols
Dr Brian Kot Chin-wing One of the issues he came across was stranded marine mammals. Such stories appear in the media, especially the heartbreaking sight of such mammals with undetermined cause of death locally and mass strandings of marine mammals overseas.
He felt sure that the use of virtopsy might help to establish why this phenomenon occurs.
Since 1983, numerous cetaceans have become stranded in Hong Kong waters. Most are finless porpoises and pink dolphins although whales have appeared, too, such as the 11-metre Omura’s whale found in 2014 on a beach at Hung Shek Mun in Tai Po.
But there were several problems. First, the body of a dead marine animal decomposes quickly, especially in hot weather, which not only makes working with the body challenging (because its tissues liquefy and gases accumulate in the body cavity), but also for hygiene and public health reasons: the body smells strongly and increases zoonotic potential to humans, which dissuades people from wanting to handle the material.
However, a chance meeting led to a connection with a veterinary imaging centre in Hong Kong that was prepared to allow Dr Kot to use its facilities.
“We found ways to reduce the costs of analysing the carcasses and producing a lot of useful data for identifying species, animal health prior to death and the possible causes of death,” he says.
Then, with the setting up of CityU’s Jockey Club College of Veterinary Medicine and Life Sciences, an ideal home for Dr Kot and his virtopsy projects was created.
Global partners, local initiatives
“We are now working with partners in mainland China, Japan, Taiwan, Thailand, New Zealand, Costa Rica and the US,” says Dr Kot. “If a dead marine mammal is stranded in these waters and on their beaches, e-material is sent to us that we can analyse and interpret and add to our database.”
The Holy Grail would be to identify reasonably concrete reasons why individual strandings to large-scale die-offs take place, affecting reproduction, causing disfiguring skin diseases and, in some cases, zoonosis, i.e. diseases that can be transmitted to humans from animals.
In the meantime, the data that Dr Kot and his team are collecting adds insight into fields such as One Health, anthropogenic threats such as vessel and fishery interactions, pollution and marine debris, sustainability and the biological health of marine animals.
The work in this field at CityU is expanding. CityU held a symposium in April 2019 on virtopsy for the characterisation and documentation of injury and death caused by human interaction, on stranded Indo-Pacific humpbacked dolphins (Sousa chinensis) and Indo-Pacific finless porpoises (Neophocaena phocaenoides) in Hong Kong waters, and collaborated with the Hong Kong Science Museum at HK SciFest 2019 with a public lecture, an interactive workshop and a first-ever cetacean-themed exhibition to highlight how a virtopsy-driven cetaceans stranding investigation reveals evidence for local cetaceans’ survival in Hong Kong waters.
Most recently, on behalf of CityU, Dr Kot and his team were awarded HK$1.2 million for 2019/20 by the Marine Ecology Enhancement Fund through a competitive peer-review process, allowing them to explore a new direction in forensic investigation into dolphin and marine vessel interaction in Hong Kong waters for injury prevention.
The results will help to facilitate for the first time an integrative assessment of identified natural and anthropogenic impacts on local cetaceans. Long-term community support through grants, convenings and communications, and by cultivating collaboration are vital to the continuous development of the virtopsy project. The results can mobilise decision-makers and key stakeholders, and transmit and translate research knowledge into action.
“We believe that, in line with the overarching theme of One Health at CityU, human, animal and environmental well-being is connected and that by working to improve these areas together, a healthier world can be established,” says Dr Kot.