- Hi, what did you do on your birthday?
- Oh, you know, ran a load of experiments to study the effect of ocean acidification on nitrogen cycling processes in the ocean around Antarctica.
Not what you would call a typical birthday activity, but it certainly beats a day in the office.
My name’s Glen Tarran from the Plymouth Marine Laboratory and I’m part of the team on board the RRS James Clark Ross that’s conducting complex bioassay experiments to see how plankton react to increased carbon dioxide(CO2) concentrations and more acidic conditions. Why? We want to see what might happen in the oceans around the Antarctic in the future due to the increasing amount of CO2 dissolving into the oceans from the atmosphere as our climate changes. My part in all this is to help study the cycling of simple nitrogen compounds such as ammonium (NH4+) and nitrite (NO2-) as they are used and transformed by the plankton, particularly phytoplankton or algae.
Nitrogen is really really important. As a gas, it makes up about 80% of our atmosphere so we breathe it in all the time…….and then we breathe it out again. However, when it’s in compounds such as nitrate (NO3+) or ammonium (NH4+) it’s a nutrient, or fertiliser for plants, both on land and in the oceans. Plants use it make amino acids and ultimately proteins and also DNA, the genetic code found in all living cells. Then the plants get eaten and those amino acids and proteins are used to make and maintain other organisms like……….us, humans. So, convinced that nitrogen’s important? Good.
However, I have plenty of music and my cruise banana to keep me company whilst I run my experiments. These basically involve adding tracer chemicals to seawater (collected in special water bottles ), incubating the seawater (see photo below), filtering the seawater (lots of filtering), adding some chemicals which react with the nitrogen compounds to form an orangy-red dye and then filtering the seawater again to take out the dye (see photo below). The dye removed from the seawater will then be measured back on land to see now much nitrogen has gone from one chemical form to another due to being used by the plankton.
Theeeeeeeeeeeeeeeen, once I’ve finished my experiments for the day I have to wash lots and lots of bottles and other equipment and let it all dry to be ready for the next experiment.
I may work pretty long hours in a small room but there are compensations: I generally have time in the afternoon to go out on deck (weather permitting) and see what the ocean has to offer. It is often dotted with pack ice and icebergs, albatrosses and petrels flying around in the sky and penguins, seals and the occasional whale swimming about in search of food. All in all, I think studying nitrogen cycling on the RRS James Clark Ross in the Antarctic is a pretty good place to spend one’s birthday.