Copepods, a group of zooplanktons, might be tiny (about the size of a grain of rice), but collectively they play a big role in regulating the carbon cycle on Earth, and thus the climate. Scientists have found that they act as a kind of 'lipid pump' in the oceans, taking carbon from the atmosphere during the summer to build up energy reserves in the form of lipids (fat), and during the winter they hibernate at great depths (a mile deep), living off that energy.
The CO2 released by during that hibernation stays down and won't make its way back to the atmosphere for potentially thousands of years, so one way to look at things is that the copepods are pumping carbon down to the bottom of the sea, transporting it in the form of lipids. Hence the 'lipid pump'.
And we're not talking about small numbers, especially not compared to the size of any individual copepod: The research showed that one copepod species alone, Calanus finmarchicus, carries between one million and three million tonnes of CO2 from the atmosphere into the depths of the North Atlantic Ocean each year.
Professor Michael Heath, of Strathclyde’s Department of Mathematics & Statistics, was a partner in the research. He said: “The deep over-wintering of these copepods has been known about for a while but this is the first time that their role in carbon storage has been measured. The results could double the estimates of how much carbon dioxide is being absorbed by the North Atlantic Ocean.
“The role of CO2 in climate change and the urgent need for action to reduce emissions is increasingly well understood. What is particularly important about our results is that the role of the lipid pump, is not taken into account in the existing climate models used by the IPCC. We need to look into this further to find out whether the same thing is happening in other oceans of the world, and how it can be included in the next generation of IPCC models.
“These copepod migrations don’t provide a solution to the emissions problem, but our results are certainly part of the process of building up a better understanding of how the planet is responding to increasing CO2 levels”.
Let's hope that our little friends keep thriving, because if we somehow screw up the oceans enough that they're in trouble, we're going to be in trouble (more than we already are) too...