A shark by any other name
Making sense of nature – ordering its different forms and naming its various characters – is a scientific practice that dates back centuries. Since Aristotle’s day, the field of taxonomy and systematics has been developed by scientists and natural historians to classify our planet’s inhabitants. In today’s conservation climate, this oft-ignored sector is increasingly important as subspecies are translocated across regions and new species are discovered with little time to spare before they disappear entirely. Dr Dave Ebert tells Lauren De Vos what it takes to attract students into what has been called a dying field and how shark taxonomy can be made exciting and relevant to a new generation and a wider audience.
Lost Shark Guy’. That’s Dave Ebert’s nickname in the shark world and it gives a clue to the purpose, and passion, he’s found in his scientific career: to search the oceans for undiscovered shark species. For a field that is often poorly understood outside the scientific world, Dave’s zeal has done much to make his discovery of more than 40 new shark species familiar to a wider audience. If ever you’ve channel-surfed different natural history documentaries, chances are you’ve encountered his work on Alien Sharks for Discovery Channel’s Shark Week or for the BBC series Shark. For scientists, his work is familiar as we page through seminal tomes like Sharks of the World to identify the various species we work with and try to understand. Dave’s background lies, in fact, in the field of ecology. For his MSc he worked on the life history of sixgill Hexanchus griseus and sevengill Notorynchus cepedianus sharks that cruise the California coast in the eastern North Pacific Ocean. It was his association with the shark taxonomist Leonard Compagno that took him to South Africa and from there on to a lifetime of searching for sharks to name and describe.
‘Just as Leonard was leaving San Francisco, I jokingly suggested that if he needed anybody to carry his bags, he should let me know!’ Dave chuckles, as he frequently does during our conversation and in a tone that betrays the enthusiasm that helps propel his work across the world and over scientific boundaries to a wider public audience. Compagno had accepted a job in South Africa at what was then the JLB Smith Institute (now the South African Institute for Aquatic Biodiversity) in Grahamstown (now Makhanda). It was there that Dave would eventually find himself settling in for a PhD and where he’d go on to describe many of the region’s shark species. That’s how he detects my South African accent via our Skype call, its flattened vowels seldom correctly identified by any other international ear. ‘South Africa is like my second country after my home country,’ he jokes, but it seems fitting that someone who has built a career on paying attention to detail would hone in on the most accurate description of my particular origin.
While it was Aristotle who first devised the key concepts of taxonomy, grouping animals with similar features in his Historia Animalium published in 350 BCE, it was the Swedish botanist Carl Linnaeus who prescribed the system of binomial classification that underpins how we order and describe life on earth today. Over the centuries, physicians and scientists had devised many varied and fairly inconsistent ways of naming and describing species by the time Linnaeus published his Systema Naturae in 1735. This system explained kingdoms, classes, orders, genera and species and, although it has been modified over time, it still forms the basis of how we classify the natural world.
Playing for time
The shark-like rays are some of the most threatened species in the sea. In the Western Indian Ocean, Dave is untangling their taxonomy, getting to know where they live and investigating their fisheries status in order to inform better conservation strategies.