Fisheries Scientist at the Marine Institute, Tom McDermott has been researching the ‘King of Fish’, the salmon for more than 40 years. “Growing up near Lough Derg in Co Clare, my father had a huge influence on me through his obsession with angling, and everything that related to the Shannon as it flowed through the lake on its way to the Atlantic,” Tom said.

“This interest led me to study a science-related course at GMIT Galway, completing a bursary in my final year at college studying eels (Anguilla anguilla) on Lough Derg with the Department of Marine.” Following completion of the course, Tom was fortunate to continue working with the Department who funded further college studies at the Institute of Technology Sligo where Tom obtained a Higher Diploma in Environmental Science.

Tom then began working with salmon and was tasked with introducing the coded wire tagging technique to Ireland, visiting North America to understand more about the salmon tagging process, and later advising Norwegian and UK authorities on its use.

“The salmon life cycle begins in freshwater, as thousands of eggs are laid in the gravel beds of fast flowing clean rivers by adult salmon that have beaten odds of two thousand to one. After one or two years they reach the smolt stage, where they move downstream, salmon beginning their epic journey in the ocean.

Using coded microscopic tags, we have been able to track these juveniles and reveal much of the mysteries of salmon, their migration, what they fed on and growth rates. After 6 million tagged and over 300,000 recoveries we understand more about the King of Fish in the last 40 years,” Tom said.  

“One of the interesting things about salmon is that it is a fish that comes out of gravel and never meet their parents, and then within one of two years, the salmon will travel all the way from Ireland to the North Atlantic and up to Greenland and make his way right back to where he started – without any directions!

An Bradán Feasa and it still holds on to many of its secrets.” Tom has worked at the Marine Institute headquarters in Oranmore since 2006, and has been involved in extensive scientific research and experiments relating to Irish salmon stocks. This research is submitted to organisations such as the International Council for the Exploration of the Sea (ICES), to inform government policy and legislation.  

“We are always monitoring survival and critically if there is enough fish to get into each river to spawn. We determine the minimum number of salmon escaping, and to make sure there is a genetically viable salmon stock. Through our research, we are also looking at the factors that might contribute to the rise and fall in survival rates of salmon at sea,” Tom said.

To be a scientist, Tom says “you just have to be curious.” “We are constantly in the field talking to fishermen and people in the industry and other scientists. You need the ability to work with different people, pick up threads and make the breakthrough links. If you have a question, then you're already looking for a link. I think that's what makes a scientist, they see a problem and are not happy until they solve it,” Tom said.

“You also need a holistic approach. Many of our scientists today have impressive standalone abilities in the fields of molecular genetics, hydrology, physiology, and in relation to habitat assessment. These are all important for a migratory species like salmon. However, due to climate change and plastic pollution we are pushed to think outside the box to solve problems for a species in the North Atlantic Ocean.

Being able to plan research, collate data and present results, is another key part of the job.” Tom says that it's important to understand as much as possible about the salmon, as the species reveal so much about our ocean. “The salmon is always collecting data for us, whether in its DNA or biotic data, the salmon is telling us what is happening in the greater Atlantic Ocean,” Tom said. “In Ireland, the salmon is revered and part of our folklore with stories of their magic abilities. The more we do scientifically, the more it seems to keep justifying that reputation.

It's pretty amazing to discover what the salmon can do. In 2019, this story of their intelligence must be told in the International Year of the Salmon”.

Marine Institute