Tag Archives: arctic

Using Yesterday’s Models for Today’s Conservation

Are polar bear habitat resource selection functions developed from 1985-1995 data still useful? (2019) Durner et. al, Ecology and Evolution, https://doi.org/10.1002/ece3.5401

The Crux

Ecologists often attempt to predict where species are using the spread of the resources that the species depends upon. This is done because often it’s simply easier to monitor the resources than the species. Resource selection functions (RSFs) are a tool which use the likelihood of a resource being used to predict a species distribution. However, if the landscape the resource is found in changes drastically, a resource selection function may start to be less useful.

In the early 2000s, using data collected in the 80s and 90s, US scientists developed RSFs for polar bears, a species which has regrettably become the poster child for the survival of the Arctic ecosystem. Even back then, the bears’ preferred habitat was receding. Now, with human-driven climate change severely reducing sea ice and markedly altering the bears’ habitat, this week’s authors wanted to know how well those RSFs work nowadays.

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Cooperation in the Aftermath of an Ecosystem Reboot

Today’s catch lays in front of me. As I marvel at how used to the stink of dead fish I’ve become, the fisher who brought them in points out a couple of larger Arctic charr as the researchers standing by him gush over the presence of a couple of tiny sticklebacks. He is fascinated by their appreciation of the smaller fish, which I had almost mistaken for baby trout. He offers to bring in more tomorrow if he can find them. It might not seem like the most significant of interactions, but it’s one more example of the willing assistance that the researchers here have enjoyed over the last week from local fishers.

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Pinning it on the Polar Bear

Image Credit: Christopher Michel, CC BY 2.0, Image Cropped

It’s an image that is ubiquitous in the media when the words ‘climate change’ pop up. The lone polar bear, drifting through the sea on a single ice floe. It is an effective image, evoking emotions like pity, loneliness and general despair for the plight of what has become the flagship species of what seems like the entire Arctic. But is associating the health of an entire ecosystem with one species useful, or dangerous?

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Interdisciplinarity in the Classroom: The Experts in Teamwork Approach

Image Credit: Liliann Eidem, CC BY-SA 2.0

The concept of interdisciplinarity (essentially, scientists from different backgrounds working together to solve scientific questions) has played a major role in the development of ecology, and science in general, in the last few decades. As odd as it sounds, working across disciplines, even those as closely related as population and behavioural ecology, wasn’t a regular occurrence. Papers with one author were fairly commonplace.

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The Pacific Oyster

The Pacific oyster could make its way further north as the Arctic and sub-Arctic regions warm

Image Credit: Hans, Pixabay licence, Image Cropped

Last Monday, I wrote about how climate change can facilitate the spread of non-native and invasive species. Today, we look at a species that whilst problematic now, could spread further throughout Norwegian waters as temperatures rise.

The last time we looked at an ocean-dweller in this series, we saw that while some species may not be great for ecosystems, they can provide an obvious benefit to other aspects of the region, in this case the fishing industry. The Pacific oyster (Crassostrea gigas) was also introduced intentionally for cultivation and is now on the verge of becoming a major problem in Norwegian waters.

What are they?

Because of its tolerance of most environments, the Pacific oyster has become the most widely cultivated oyster in the world, and thus one of the most widely distributed alien species in the world. Originating from the North-West Pacific, around Japan, it’s sometimes referred to as the Japanese oyster. There is some confusion regarding its taxonomy, with it also sometimes referred to as the Portuguese oyster, though it’s possible the two are separate species. They are large, jagged oysters, and occur in marine coastal waters.

How did they get here?

The oysters were imported into waters throughout Scandinavia and most of Northern Europe to replace dwindling stocks of native oysters at various points through the 20th century. Naturally, they eventually established wild populations as well, and are now abundant along Norway’s southern coast. Whilst they have taken over coastlines through much of Europe, their dislike of colder waters means that for now, their local populations are largely constrained to the south of Norway. But increases in temperature, which will occur at an accelerated rate in the Arctic and sub-Arctic, mean that the oyster could spread further north in the coming decades.

1200px-Pacific_oysters

Whilst the Pacific oyster’s place in novel marine food webs is still not particularly well understood, these specific oysters place in their immediate food web is very obvious (Image Credit: gautsch, CC BY-SA 2.0)

What do they do?

Much like the Red King Crab, they transform the local ecosystem into a homogenous mass. They can transform substrate from soft bottomed and muddy to filled with rocks and other oysters and mussels, also paving the way for other alien species, and lowering regional biodiversity by outcompeting and displacing local species. Interestingly though, presence of oysters can often improve water quality in the surrounding regions and heighten ecosystem productivity, though the position of the oyster in novel food webs is not particularly well understood. They also have negative effects for local human populations, making certain areas impossible to use for recreation, as they’re extremely sharp.

How do we stop them?

In other countries, attempts to eradicate wold populations by harvesting them have proved futile, and a 2005 study showed the oyster eradication would also cause substantial harm to the local ecosystem. Warming seas will mean the expansion of the oyster’s range, however this is likely to happen very slowly, so by focusing on the ranges edges it may be possible in the future to limit expansion.

For more information on the oyster, we recommend that you read the following articles:

Invasive Alien Species Fact Sheet – Crassostrea gigas by the Online Database of the North European and Baltic Network on Invasive Alien Species

Crassostrea gigas – Cultured Aquatic Species Information Program by the Fisheries and Aquaculture Department of the United Nations