Uncovering the role of 'the wicked element' in the environment

“Many countries have declared a climate emergency, implicitly accepting that the trajectory of environmental degradation cannot continue and new thinking is needed. Trying to understand how environmental systems work in a period of rapid global change can feel daunting at times. However, as a scientist I feel privileged to make a contribution to address environmental challenges while having the opportunity to teach the wonderful subject of chemistry.”

Professor Mark Fitzsimons is a leading researcher on the interactions of nitrogen and other chemical compounds in the marine and terrestrial environments, motivated by his desire to help understand environmental processes through chemistry.

His interest lies largely in the environmental cycling of nitrogen, including the under-studied methylamines that are present in the ocean at very low concentrations and are potentially important in climate regulation processes. His research in this area has focussed on how to measure these challenging molecules so that their role in marine ecosystem functioning and their transfer and reactions in the atmosphere can be understood.

“Nitrogen has been described as 'the wicked element', as it exists in so many different forms; the characteristics that make it essential to organisms also create complex challenges as we add more and more reactive nitrogen to the environment.”

Hailing from County Down, Northern Ireland, Mark grew up with playgrounds of both the Northern Irish coastline and the Mourne Mountains and a family history of farmers and sea captains.

“My landmarks on our long car journeys to my mother’s hometown in rural County Derry were things like the soil changing colour as they became iron-rich west of the River Bann, so even as a child I suppose I was using science as a way to orient myself. The land and the sea were an integral part of my childhood.”

He has been driven throughout his education and career to apply this interest to the real-world. But he nearly followed a path into the arts – “I might’ve studied History with Politics or similar.” Mark believes that science and the arts aren’t as different some would think.

“My violin teacher would say ‘you can strive for technical excellence but you need emotional connection’, and I think that is true for science, too. You need imagination and passion to do the work.”

While his creativity is most obviously expressed through playing Irish music on the fiddle, Mark’s scientific curiosity often couples the development of challenging analytical methodologies with experiments to understand the behaviour and impacts of nitrogen-containing chemicals.

Methylamines first captured his interest during his BSc Chemistry with Oceanography and consequent PhD studies at the University of Liverpool. Professor J.P. Riley gave him a final year project to look at their concentrations in cultures of marine algae as it was a time when little was known about these compounds.

A short post-doctoral stint with the Marine Biological Association, Plymouth, first brought him to the city where he studied the chemistry of marine environments with a gradient of oxygen levels.  

Mark resumed organic nitrogen research while lecturing in Environmental Chemistry at Middlesex University, before returning to Plymouth in 2001 to join the University.

“I knew some of the chemistry staff at Plymouth and had always admired the way that they applied a robust understanding of theory and chemical analysis to address environmental questions. The city also has three great institutions – the University, Marine Biological Association and Plymouth Marine Laboratory – for collaborative marine research.”

Mark’s interest in analytical development alongside his then PhD student, Dr Charlotte Cree, led to them establishing a new method to analyse methylamines at very low concentrations and, most importantly, be widely available to the oceanographic community without the need for expensive specialist equipment. After initial success, Mark was soon approached to take this method to one of the most challenging marine environments on earth.

“Charlotte joined an international research cruise to Antarctica – one of Earth’s most pristine and isolated environments – to measure the production of gases from plankton in the Southern Ocean. It was a big risk to test the method and equipment in such hostile conditions. We had plenty of challenges and WhatsApp exchanges to solve analytical problems! Thankfully it paid off with really good data and I’m very proud of that achievement.”

Mark has also contributed significantly to investigating the impacts and environmental pathways of pharmaceuticals that have washed into our rivers and waterways, including benzodiazepines like Valium, which are a more recent environmental concern.

“There are tensions between the great benefits of medicines to humans and the negative impacts that pharmaceuticals can have on other organisms when they enter natural waters. Working with others, I was able to show that, depending on the environmental conditions, sunlight and bacteria could degrade the molecules and efficiently remove the contamination; this was one of the first proposed removal pathways based on complete experimental evidence.”

Mark’s interest in nitrogen chemistry and the search for solutions to soil degradation and scarcity has brought him back to land, where he has worked closely with the Eden Project to develop soils constructed from inert waste materials. Through the ERDF-funded FABSOIL and Interreg FCE-funded ReCon Soil projects, Mark and his collaborators have produced soils from suitable waste materials, working to improve their efficiency and nutrient retention, and influence both their deployment and the regulations surrounding their use. His vision for this work is to show that reconstructed soils are a viable option for communities across the world who need to rebuild their soil resources.

“People want to embrace reconstructed soils but we need to understand how they will safely function in the long term, and how their chemistry and biology is regulated. It’s an exciting time because there’s such a focus on the circular economy, reusing materials and the potential of soils for carbon capture.”

Underpinning Mark’s career is a motivation to go where his expertise is needed, whether developing analytical methods, supporting early career researchers, or moving metaphorical mountains to empower his students in gaining relevant experience.


I enjoy research that has a purpose and also seeing the next generation of scientists learn and progress in their careers. For me, rather than ask why something should be done, I ask – why not?



Current projects and research activity