Thomas Horton
Who I am
I grew up in a land-locked village in rural England and, perhaps oddly, have always had a fascination for water. Like others who didn’t have the ocean in their back garden, my intrigue was fuelled by fishing in local rivers and the wholesome pursuit of rock pooling when on family holidays. My father was, and still is, a keen fly fisherman and when my three brothers and I were young he taught us how to fish. Family holidays were spent in the Channel Islands off the UK, where rock pooling, jumping off the cliffs into the sea and barbecues on secluded beaches were our daily pursuits. Training to be a marine biologist was my plan from as far back as I can remember, and after finishing at college I was accepted at the University of Southampton. There, over four years, my passion was fostered into a craft as I trained at the National Oceanography Centre. My Master’s project (looking into fine-scale controls on the use of space by basking sharks, sunfish and harbour porpoises) introduced me to Cornwall, a rugged peninsula that makes up the furthest western and southern reaches of the British Isles and is packed with sea life and marine culture. Having worked abroad for a period, I now call this place home and spend my days with my young family exploring the nooks and crannies of this endearing corner of the world. Through my work as a marine conservationist, I aim to do my part to protect the animals, ecosystem and culture I love and respect, both in Cornwall and further afield.
Where I work
Our project is based in Cornwall in the UK’s far south-west, which is where my PhD brought me to research the Atlantic bluefin tuna, a species brought back from the brink and a true story of how good, scientifically robust management can work. Rugged near-shore reefs are home to numerous large species, and porbeagle sharks are an established visitor to the surf-soaked shores. Commercial fisheries, occurring far beyond the near-shore reefs, have reduced our porbeagle populations to a fraction of what they once were. To help populations recover, we are searching for clues in the porbeagle population off Cornwall that indicate how and where these elusive and endangered predators give birth. We hope that what we learn from Cornwall’s porbeagle sharks will provide a fundamental understanding of some of the species’ most basic processes and that this understanding may be used to help populations recover.
What I do
As a marine conservationist, I am particularly interested in how using applied methods can achieve conservation gains. Much of my recent work has focused on the use of bio-logging technology to study how fish move and behave, providing clues into their secret lives that can help us protect them. A good example is understanding how and where animals reproduce – a time when they are most vulnerable to stressors. Using bio-logging tags, we have successfully tracked Atlantic bluefin tuna from UK shores on their annual migrations to the Mediterranean Sea and back. The treasure trove of information stored on the tags carried by the fish has helped us understand how large the tuna are when they reproduce, the time of year and day that they are most likely to give birth and how long the reproductive season lasts.
In this project a typical day involves applying some of this approach to porbeagle sharks, while also marrying it with cutting-edge analysis of blood biochemistry and at-sea ultrasonography. We are collaborating with recreational fishermen to catch and handle sharks, so that we can sample shark blood, use ultrasound to detect any foetuses they may be carrying and attach transmitting tags to their dorsal fins. Part of my research is on how best to refine angling methods for sharks to increase post-release survival, so we are also working closely with anglers to ensure that the highest welfare standards are always maintained.