Real Voices interview: Rupert Houghton
Meet Rupert, a PhD student studying crayfish populations
What do you do?
I am a first-year PhD student at the University of Aberdeen using population-modelling techniques to find the most effective combination of eradication methods for managing the invasive American signal crayfish (Pacifastacus leniusculus) in Scotland, taking into account each method’s seasonal, size and sex bias.
How did you get into population modelling?
It’s always been my ambition to forge a career in the natural sciences. I studied biology, physics and maths at A level, completed my BSc in biological sciences, my Master’s in ecology, evolution and conservation, and have worked for several ecological consultancy firms.
I applied for my PhD because I am interested in the ecology of aquatic animals. I’m using population modelling specifically because it allows you to answer important conservation questions without having to conduct large-scale, expensive and impractical experiments.
What is the most interesting thing about your population model?
I am very excited about using population modelling to solve my research problem for two reasons. Firstly, in the branch of mathematical modelling that I am using (deterministic matrix modelling) invertebrates like crayfish have rarely been used, so it will be a relatively novel application of this technique.
Secondly, using my model I’ll be able to inform real ecological management strategies, which could eventually be incorporated into the daily routine of river and fishery managers all over the UK, and possibly even across Europe.
What is an average day like when completing fieldwork?
I’m currently working with a group of volunteers on the River Nairn, not far from Inverness. We meet weekly, checking crayfish traps and counting, sexing, measuring and weighing the crayfish captured.
How much time do you spend in the field doing research, and what is the balance between field- and desk work?
I am currently planning a very active year of fieldwork. By the end of my first year it is likely that I will be spending around three months in the office for every month in the field, which I think is a comfortable balance. A lot of office time is required to find out what is already known about the research problem, identify specific research questions, design studies to answer the questions asked and analyse the data produced.
What would you like to achieve using your population model?
I’m interested in finding out the movements of crayfish exposed to different eradication methods, as we may find that it’s easier to slow down the spread of the crayfish than to reduce their numbers. Finding this out will involve adding more layers of biological detail to my model, such as density-dependent dispersal rates and dispersal distances.
Do you eat crayfish?
I don’t eat signal crayfish. If culinary value is attributed to them, people will likely spread them into new catchments to harvest them. Also, harvesting may actually encourage population growth, because traps typically catch large males, who dominate subordinate crayfish and reduce the survival and growth of juveniles.