Plankton is the foundation of the food system for Arctic marine life. However, rising sea temperatures in the Arctic are having an impact on various plankton species, leading to the risk of food insecurity for communities in the region.
Episode written and produced by Ulla Hemminki-Reijonen (Harvard Graduate School of Education), Sarah Littlefield (Harvard Graduate School of Design), Annick Steta (Harvard Kennedy School), and Jenna Wu (Harvard Graduate School of Design).
Interviewee: Finlo Cottier, Scottish Association for Marine Science.
Music: Original northern lights audio recordings provided courtesy of NASA and The University of Iowa (Space Audio); music licensed by Soundation AB; arrangement by SarahMackie; Sound of whales spouting is included courtesy of the US Fish and Wildlife Service.
The views and opinions in this podcast do not necessarily reflect those of the Arctic Initiative, the Belfer Center or Harvard Kennedy School.
Hello everyone and welcome to Northern Lights, the Harvard Arctic Initiative Student Podcast.
Today we have our first of three guest episodes from Harvard Kennedy School’s Policy and Social Innovation for the Changing Arctic course. During the course students had the option to create a podcast as one of their assignments and we are delighted to be able to share their work with you.
In this episode the students report on how rising sea temperatures in the Arctic are having an impact on various plankton species, leading to the risk of food insecurity for communities in the region.
This is Ulla Hemminiki-Reijonen, Sarah Littlefield, Annick Steta and Jenna Wu with ‘Climate Change and the Arctic Food Web’.
Many Arctic communities still rely on subsistence hunting for whale, seal, fish, and caribou. But the changing climate is rapidly destroying these traditions that have developed over millennia. The impacts to Arctic wildlife are widely varied from melting sea ice to pollution. But one less known impact to Arctic wildlife is coming from an invisible battle deep in the ocean. Climate change is changing the population of two types of plankton that live in the Arctic Ocean: phytoplankton and zooplankton.
The phytoplankton are the prey of zooplankton for sure, yes.
This is Professor Finlo Cottier. He is an oceanographer with the Scottish Association for Marine Science.
And a lot of the phytoplankton that is produced in the service is very quickly consumed by the zooplankton. And often it's not the bigger zooplankton – the sort of 3, 4, 5 millimetre-sized zooplankton that you find and is called micro zooplankton, you know, that is really, really concentrated with micro zooplankton. They will consume a lot of this phytoplankton. And the zooplankton then converts the carbon into lipids as form of fat and zooplankton gets eaten by the fish and the whales, and so and so forth. And that's what affectively fuels the food web.
Phytoplankton blooms make water warmer, whereas zooplankton require colder water. As the ocean warms, it becomes less suited for zooplankton and better suited to phytoplankton. So the phytoplankton is taking over. This can have impacts all the way up the food chain.
Dr Cottier is the lead investigator of the Arctic PRIZE project, which aims to understand and measure change in the Arctic ice zone, particularly seasonal changes.
We were also looking at the phytoplankton of course. This is the sort of fundamental foodstuff of the Arctic and the timing of that phytoplankton growth, what we call spring bloom, is a key parameter in the Arctic - when it occurs, where it occurs, how long it occurs, the amount of carbon that it fixes in that process, and how that carbon is then - that's actually the currency of energy- how that's then transferred through the rest of the food web system.
So the next stage down from phytoplankton is zooplankton. They graze on the phytoplankton. And species of zooplankton in the Arctic are real keystone species for fuelling the sort of higher trophic layers -the fish and the whales and seals. So the zooplankton is a really important component.
Dr Cottier describes the Arctic as a surprisingly dynamic place. But the Arctic can be a difficult place to take measurements in the traditional way because you can't measure lights during times of midnight sun on polar night. So the research team had to get creative, using things like acoustics and new technology like robot gliders.
Remarkable things happen in the winter as well. It's not a sort of a dormant, lifeless, featureless biosphere that you might imagine it to be. It's very, very active, surprisingly active. And so the Arctic PRIZE project was deliberately conceived to span that time period from the winter through the spring, which is extremely active, and into the summer time, and to try to make consistent sets of measurements that span the physical, chemical, or biological processes in winter, spring, and summer. Again, quite often the way the science is organized, you will have a predominantly physics based expedition or predominantly biological based expedition, or one that's focused on the seabed, or one that's focused on zooplankton, but then to take the approach of having one of everything on the ship so that we try and take a measurement of all these parameters was a challenge, but it also allowed us to really sort of start piece together the pieces of the puzzle. But then you have the question what happens in between the times when you're at sea. What's going on there? How is the water evolving? How are phytoplankton populations evolving whilst you're not present there on a ship? And that's where we brought in the robotic capabilities. So we used ocean gliders, which effectively navigate themselves.
I have seen a picture during our climate course of a seal with a form of captor on the top of his head. Is it something that you use or not at all?
Seals are great. They can go to places where ships wouldn't normally try and go. They can actually get very close to the boundary between the ice and the water.
Studying these types of plankton is so important because they are the foundation of the food system for Arctic wildlife.
A word that's often used is fragile. You know, the fragile Arctic ecosystem. And you know, we're finding ways in which the Arctic is actually somewhat robust and malleable. And it can absorb some of this change. However, at the higher levels of the food web, some species, and particularly birds, will selectively feed only on particular species and only particular size classes of species. You sort of have an impression sometimes of birds just kind of scooping up whatever they can find. But some of these species are very specific in what they choose to eat. Some species will probably struggle to adapt. Other species have a much more what we call plastic response to change and they can change more readily. There's a certain school of thought which says that Arctic ecosystems have a resilience to them, which is perhaps underestimated. And the way it's communicated, as I say, is often used in this term of using words like fragile. And certainly the actual Arctic environment is susceptible to change. We know that, we can see it, it's happening very fast. But perhaps the ecosystems within it, and certainly the foundations of that ecosystem, the phytoplankton, the zooplankton, perhaps have a resilience that is underestimated.
Of course, the higher levels, the fish, the whales, the birds, the bears, they will perhaps be affected in different ways. Many of them use ice as within their life cycle. They use ice for breeding or hunting. So the loss of ice and the way that ice provides a platform for movement or shelter or rest then becomes important.
Looking at the large-scale basis of the ecosystem -phytoplankton, zooplankton- there may be some resilience there that we underestimate. For the higher trophic levels, for sure there are going to be difficult consequences. Again, a word that's used often is a cascade. You know, what happens at the one end of the food chain cascades through to elsewhere. So with the phytoplankton, different ocean properties will tend to support different kinds of phytoplankton. One is classical diatoms, which are very silicate rich. They have this sort of case and they have a particular nutritional quality. Another type is Phaeocystis phytoplankton that has a different nutritional quality. It thrives in different conditions, more sort of open ocean conditions perhaps. And so the food quality that those phytoplankton accumulate then cascades through the system. And so it's not just a case of will there be more or less phytoplankton. It's also the type of phytoplankton and the food quality that that then generates is really important. And that is again where a lot of the contemporary research is -you know, what are the underlying drivers that would determine and dictate which species of phytoplankton will dominate at any one time. Knowing that gives you some indication of the food quality that will result from that.
So sort of zooming out to this macro scale, I guess, what are your thoughts on how the Arctic community has been portrayed through, you know, the lens of oceanography through which you explore the Arctic?
Another aspect is one of knowledge -both traditional knowledge and contemporary knowledge as well. And again, we sort of run around on ships and putting instruments or robots in the water and explaining how the environment is changing. And yet there is some very, very rich knowledge to be gained from the people and communities who have both experienced the change and are adapting to and having to live with the change.
Many of the people living in the Arctic experience food insecurity. That means living without reliable access to enough affordable or nutritious food. These disruptions in the food system, along with melting ice, have made Arctic communities more reliant on imported food from the South.
We spoke about this issue with our classmate, Elsennguaq Silassen, who lives in Greenland. Elsennguaq said that some people in Greenland are able to hunt and fish to support themselves throughout the year. But not everyone has that option. And for the people that are reliant on products available at the supermarket, the imported and unhealthy junk food is often much more accessible than the more nutritious local meat and produce. And for indigenous people, being able to hunt for local food is more than just calories. It's the continuation of their culture and traditional knowledge.
What should be done to help the situation?
What should be done? What can we do? As individuals, you know, we can't reverse the cycle of sea ice at all. I think at the most basic level we take notes. We take notes, and we then decide that it's an important, a really important change. And the scientific evidence and investigation can help explain why it's an important change both from a climatic point of view and an ecological point of view. Then it would hopefully build some kind of consensus, some sort of momentum. Yeah, I tell you that on a very personal level I do ask myself the question or I sort of prepare myself for the day when my two boys ask me the question: “So Dad, when all this climate business was going on and the Earth was falling into pieces, what were you doing?”
I’m extremely aware of the misuse of or the representation of the Arctic being some sort of fringe land, you know, sort of living at the extremities of the Earth and all this sort of thing. Well, if you live there and that's your home, then it's the centre of the world, really.
Today’s episode was written and produced by Ulla Hemminki-Reijonen from the Harvard Graduate School of Education, Sarah Littlefield from the Harvard Graduate School of Design, Annick Steta from Harvard Kennedy School, and Jenna Wu from the Harvard Graduate School of Design.
We would like to thank Finlo Cottier from the Scottish Association for Marine Science for his time and expertise.
This podcast was created as part of Harvard Kennedy School’s Policy and Social Innovation for the Changing Arctic course, taught by Halla Logadóttir.