The ARISE project (which is part of the UK program ‘Changing Arctic Ocean’) aims to study changes in the Arctic food web. The Arctic is warming due to climate change. So, we want to look at “what are the changes” and “what consequences they have on the animals living in the Arctic”.
For that we will study the carbon and the nitrogen in the food web, because they constitute the organic matter which are in all living organisms (including you!) With biochemistry, we can follow these atoms (Carbon and Nitrogen) along the food chain. It follows the basic principal of “you are what you eat”.
For example, if Robyn eats only potato, the nitrogen inside the potato (let’s call it “potato- nitrogen”) will be found again in Robyn. If Elliott eats only beefsteak, the beefsteak-nitrogen (which is different than the potato- nitrogen) will be found in Elliott. It is the same in the Arctic, if a seal feeds on an Arctic fish, the Arctic fish-nitrogen will be found in the seal. The Arctic fish feeds on zooplankton, so the zooplankton-nitrogen will be found in the Arctic fish and so on.
An example of the Arctic habitat and food web
During this cruise, Robyn and Celeste will measure the nitrogen and carbon which are dissolved in the Arctic water. This is the very bottom of the food chain. The phytoplankton (really tiny plants floating in the ocean) use the dissolved nitrogen and carbon to grow. So, I will also collect the particles (formed by phytoplankton) in the water and measure the carbon and nitrogen in them. In addition, Elliott will collect the zooplankton (the insects of the ocean) which feed on the phytoplankton. Later on, we will measure the nitrogen and carbon in Arctic seals, which are at the top of the food chain (before the polar bears which are the very top).
We will therefore have followed the nitrogen and carbon all along the food chain and we will be able to find out, whether anything has changed in recent years within the Arctic food chain.