Centre for Chemical Sciences
School of Earth, Ocean and Environmental Sciences
University of Plymouth
What questions related to the Arctic are you trying to answer? My main area of interest in the Arctic concerns the sea ice. This is the part of the Arctic Ocean that freezes in the winter and melts in the summer. In recent times, there has been growing concern that the amount of sea ice is getting smaller and smaller due to global warming. In order to better understand how important these changes are and how they might affect the planet in the future, we need to have a much better understanding of how the amount of sea ice has changed in the past. At the moment, we have good sea ice records for about 30 years, but that’s not really enough if we are trying to make good predictions for the future.
Sea ice is very important for a number of reasons. Firstly, it acts as a kind of ‘sun-screen’, limiting some of the sun’s rays from warming our oceans. Secondly, it plays a role in controlling the currents in the oceans and therefore contributes to things such as the Gulf Stream. Thirdly, starting with bacteria and algae, and finishing with large mammals like polar bears, it plays a key role in biological food chains in the arctic and Antarctic.
How will answers to those questions help us understand more about our world? At the moment, it is clear that we are experiencing a period of warming on Earth. What is less clear is how the influence of humans is contributing to this and how much of this warming is due to natural processes. Both are evident, but what are their relative contributions? In order to answer these questions, we need to understand how the natural processes influenced the Earth before mankind could have had any influence. In addition, if we have a better idea of the importance of these factors, we can better advise recommendations for the future. From a biological point-of-view, by examining the plants and animals that live in or on top of the sea ice, we can better predict the effect that reducing the sea ice will have on life in the polar regions of the planet
How are you trying to find the answers to those questions? To examine historical record of sea ice on Earth, we are carrying out experiments with Arctic sediments or the mud that lies at the bottom of the ocean in the Arctic. This may seem strange at first, since we are interested in the sea ice at the sea surface, not what goes on at the bottom. We do this because ice melts in the summer, so there is no direct record of its occurrence.
Instead, we use a ‘fossil-approach’. Certain micro-organisms live in the ice and grow really well during the Spring. When the ice melts in the summer, they fall through the sea water below and [settle] into the sediment or mud on the ocean bed. These organisms are very fragile and dissolve easily releasing some chemicals into the mud. Just as we use fingerprints to identify if a person has been in a particular location or has handled a specific object, we know if the chemical is present in the mud, there must have been the micro-organism that made it which, in turn, means there must have been sea ice at that time. If the chemical is absent, then the sea ice must have been absent.
By analysing long sections of mud which might be tens, hundreds or even thousands of years old, we are able to use this fingerprint approach to build a historical record of Arctic sea ice. To better understand the influence of the sea ice on biological organisms, we use the same fingerprint method to trace which animals are feeding on the organisms in the ice and which are found higher up in the food chain.
Recount for us one of your field days in the Arctic. No two days of work in the Arctic are the same. With changes in location, changes in the weather and problems with scientific equipment, there is usually something to get in the way of best made scientific plans!
On one occasion in 2007, I was taking part in some fieldwork aboard the Canadian ice-breaker, CGS Amundsen. We were sailing from East to West through the North-West Passage in northern Canada. Unusually, all of the conditions were perfect. Fantastic sunny weather, virtually no wind and all of the equipment on board was working. We were having a perfect day for sampling the ice, the water beneath the ice and mud on the ocean floor beneath all of that.
During a brief break, we took a trip to the top of the ship (the bridge) and admired to view in all directions. Everything was very still and peaceful. All of a sudden, the captain announced that she had spotted two well-camouflaged animals moving on the ice a few miles away on the horizon. It could only mean one thing-–polar bears.
All 70 of the crew and scientists on the ship assembled on the deck, jostling for position in hope of catching a rare glimpse of these symbolic creatures of the Arctic. To our amazement, as the ship slowed down and approached them, the bears did not run away but, in fact, came even closer. All this, despite us being on the only ship around, a hundred metres in length, thousands of tonnes in weight and bright red!
Eventually, the mother and cub were directly next to the ship and everyone was able to take photos and make videos. It was a real treat. After a few minutes, the polar bears retreated behind a small iceberg, the ship changed direction and it was time to go back to work. It was an unforgettable experience.
What do you find most rewarding about being a scientist? There are many things that are exciting about being a scientist. Firstly, you get to travel to some parts of the world that some people can only dream about. Secondly, you get to work on real world problems that are important to everyone on Earth. Thirdly, you get to do experiments and make discoveries that nobody else has ever done before. Finally, through the media, you get to tell the world about what you do.