Climate Change and the Availability of Marine Foods for Inuit

How does climate change affect the amount of marine foods available for the people of Qikiqtarjuaq in Nunavut, Canada? No one knows for sure, but we did some research in collaboration with Inuit partners to better understand what Arctic marine food webs can look like in the future, and what this means for Inuit food security. Here is what we found!

Inuit subsistence in the Arctic under climate

The Arctic is one of the most sensitive regions to climate change on our planet. The temperature here have increased up to three times the global average. Recent changes in sea ice conditions have effects on the life cycles of animals and plants. For example, when the ocean warms the sea ice melts earlier in the spring. Consequently, the algae
aquatic plants.
growth also starts earlier since it begins when there is enough light. This change in timing affects species that eat algae, like zooplankton, and those that feed on them and so on –that is, the whole marine food web
A food web is who eats who. It is a network of species that interact with each other through feeding relationships.
.

Besides changes in the amount of algae in the ocean, some Arctic species are moving further north to places with conditions that suits them better, like lower water temperature. Other species are following their prey to new places or changing their diet, which may influence their nutrient and fat levels.

And in places where boreal species in biology, a species includes animals, plants, bacteria or fungi that share common characteristics and can reproduce together. For example, dogs belong to the species Canis familiaris. are becoming more common, these may compete with Arctic species for food, or bring more parasites. Local fish and marine mammals are among some of the favorite foods of Inuit. In Qikiqtarjuaq, a Nunavut Inuit community situated off eastern Baffin Island, the most eaten marine foods are ringed seal, narwhal, and Arctic Char. These are rich in nutrients and healthy fats, and very important for Inuit tradition, culture, and food security. This means that changes in marine food webs influence the ability of Inuit to get their traditional foods, and therefore their food security. Capturing the effects of climate change in so many species, from algae to polar bears, and figuring out how this affects Inuit, is not a simple task. How can we approach such a problem?

Marine food web in West Baffin Bay

Marine food web in West Baffin Bay polar bear ringed seal seabird
Western Baffin Bay​ Map

Western Baffin Bay

Western Baffin Bay goes through a full annual cycle: in the winter it is covered in sea ice whereas in the summer it is completely ice-free. Baffin Island, with its countless fjords along the coastline, provides the ideal spot for many marine species to nurse their young and to feed, especially when ice-free.

Modelling the food web

We created a food web model
a mathematical equation, an algorithm, a picture, or a graph that represents a network and how its components interact with each other.
representing the interactions among marine species in western Baffin Bay, Nunavut. A model of this complexity is more informative when looking at the broad effects of climate and other environmental changes on marine species compared to models with just one or two species. This is because a food web model includes the reliance of species on one another for food. For example, if a prey species becomes less/more abundant, their different predators will have less/more trouble finding food and may also become less/more abundant.

We developed this model with the community of Qikiqtarjuaq to :

1. Better understand the local food web, and how climate change affects the amount of marine foods available for the community.

2. Create scenarios of future change and analyze what these scenarios mean for animals that matter most to the community. This allowed us to think together about how Inuit could adapt their food sources in years to come.

These models were created with Ecopath with Ecosim (EwE) ecosystem modelling approach and software. Ecopath is a tool to represent the food web, while Ecosim is a tool that represents how the food web varies over time and allows us to evaluate model scenarios. To develop these models, the data used included estimates of abundance
Abundance of a species is the number of individuals of that species.
of species, diet composition, growth rates and mortality rates of all species in the food web. We took this data mainly from survey reports, Western scientific literature, and expert knowledge. From abundance we calculated biomass, which we used as the quantity of food passing from prey to predator in the food web.

Narwhal

Narwhals
Monodon monoceros

 

Narwhals of the East Baffin Bay population a group of animals of the same species that live in a certain geographic area at the same time. spend the summer, from June to September, in the fjords of Baffin Island. After that, they travel for about 1,700 km to southern Baffin Bay where they stay until late March/early April. At this time, they move back north to the Baffin fjords. Narwhal most common preys are Arctic cod and Greenland halibut.

Arctic char

Artic char
Slavelinus alpinus

 

Arctic char is a fish that spends part of their life in freshwater and  another in the ocean. In the Baffin region, this fish spends the winter in rivers and lakes in Baffin Island, where they reproduce. As adults, they migrate through the fjords and into Baffin Bay coastal areas when the rivers are ice free. They normally spend the summers feeding on zooplankton in marine waters along the coast and move back into freshwater during the fall.

Ringed seal

Ringed seal
Pusa hispida

 

This seal is completely adapted to ice-covered waters and does not travel in the winter, staying in Baffin Bay year-round. In the summer and fall, some seals remain close to their breeding sites while others disperse along the coastline. Some spend time in the open water far from the coast, and others move north to the ice edge. They eat mainly Arctic cod and zooplankton.

Polar Bear

Polar Bear
Ursus maritimus

 

Polar bears can move quite a lot across Baffin Bay and up to the North Water Polynya. In the winter, bears can be found on the sea ice in the bay looking for their favorite prey – the ringed seal. In summer, the bears use either eastern Baffin Island or the Melville Bay area as a summer retreat. Besides ringed seal, bears also eat other seals that spend the summer in the area.

The modelled scenarios

Note that model scenarios are not a prediction of the future. Instead, model scenarios help understand how our actions can lead to different possible futures. With this information we can better prepare to adapt to climate change.

IN CONSTRUCTION

construction cone

Glossary

Species – in biology, a species includes animals, plants, bacteria or fungi that share common characteristics and can reproduce together. For example, dogs belong to the species Canis familiaris.

Population – a group of animals of the same species that live in a certain geographic area at the same time.

Network – a group of interconnected people, other species, or things. For example, Facebook is a network that connects people all over the world.

Food web – A food web is who eats who. It is a network of species that interact with each other through feeding relationships.

Model – a mathematical equation, an algorithm, a picture, or a graph that represents a network and how its components interact with each other.

Model scenario – a possible new arrangement of a network (represented in a model).

Food security – a food secure community is a community that has access to enough, nutritional, and safe (not contaminated) food.

Abundance – of a species is the number of individuals of that species.

Biomass – is the number of individuals of a species multiplied by the average weight of individuals of that species. For example, we use biomass of a fish population to determine how much of that fish is available for fishing.

Algae – aquatic plants.

Collaborators

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