Those predators will become fellow researchers and study climate change. Find out how they can help !
If there is one ecosystem that is particularly sensitive to global warming it is sea ice: the layer of ice formed on the seas when temperatures droplow enough.Since the 1980s, we have seen a decrease of 3.8% per decade in the area of sea ice in the Arctic and of 1.5% in Antarctica. Moreover, the scientific future scenarios of the Intergovernmental Panel on Climate Change (IPCC) expect melting to accelerate in the years ahead.
What are the present and future consequences of reduced sea ice for the species that live, hunt and breed there? This is what the Sentinels of the Sea Ice (SENSEI) project wants to find out, with the help of its 13 teams of researchers from six countries, and the support of the French Polar Institute (Ipev). How? By using eight top predator species as environmental indicators of the North Pole and South Pole.
“ All climate models, even the more optimistic ones, show that the sea ice surface area will diminish dramatically over the next century. We want to pre-empt the consequences of this gradual decrease by observing predator response as accurately as we can. ”
CNRS at Centre d’études biologiques de Chizé (CNRS/University of La Rochelle)
Eight sentinels
Christophe Barbraud (CNRS) of Centre d’Etudes Biologiques de Chizé (CNRS/University of La Rochelle) puts it in a nutshell: “observing as accurately as possible how these sea predators respond to changes in the sea ice could give us insight into the current state of health of these ecosystems, as well as the changes we can expect in response to current global warming”.
The eight “sentinel” species are two flying birds (the snow petrel in Antarctica and the black-legged kittiwakein the Arctic), three diving birds (the Adélie penguin in Antarctica, the thick-billed murre and the black guillemot in the Arctic) and three earless seals (the Weddell seal and elephant seal in Antarctica, and the hooded seal in the Arctic). The species’ demographics have been monitored extensively - some for over 40 years even - which gives the researchers a solid foundation to work from.
In addition to this demographic approach, the researchers will go into the field to collect data on hunting behaviours. Tiny sensors have been placed on several individuals to record where and when they go hunting and what effort they put into capturing their prey. The sensors will also take readings from the environment (temperature, pressure), the density of prey thanks to acoustic and visual data, and the depth of the sea ice using a sonar system. Combined with satellite data, this information will give the researchers an on overview of the predator species and the sea ice.
Change occurs much faster in Antarctica than they in the Arctic and may well be precursory to what will happen in the South Pole.
“It will also be interesting to compare the different areas being researched, especially the two poles”, adds Yan Ropert-Coudert, co-director of the project with Barbraud. “Change occurs much faster in Antarctica than they in the Arctic and may well be precursory to what will happen in the South Pole.”
What about tomorrow?
The researchers hope to use this data to model the future evolutions of these populations according to different future sea ice scenarios. “We’ve done exactly that with emperor penguins and predicted a 19% decrease in their population worldwide by 2100. We would now like to look at sea birds and mammals and compare, for example, the reaction of flying birds -theoretically not as sensitive to the reduction of the sea ice - with that of diving birds, which have a strong reaction to current warming”, explains Barbraud.Another scientific endeavour of theproject will be to establish a series of indicators (population abundance, survival and reproduction rate, stress levels as measured via hormones,etc.) that will give an idea of the state of health of the different locations being researched. These indicators could be used for ecosystem management projects. But the SENSEI project’s ambitions are not only scientific; it also aims to communicate as widely as possible on the fragility and beauty of this environment.
In partnership with Luc Jacquet’s Wild Touch association, there will be a dedicated website to raise public awareness of the, and a series of conferences and talks at schools have been planned.