Tag Archives: introduction

The Asian Ladybeetle

The Asian Ladybeetle, which has now established itself in Norway and will likely be a permanent fixture in our ecosystem

The Asian Ladybeetle, which has now established itself in Norway and will likely be a permanent fixture in our ecosystem (Image Credit: Scott Bauer, CC0)

Reasons for deliberately introducing novel species vary, from their aesthetic appeal to a boost they may provide the economy with. Using them for biological control is another, and it has led to some of the world’s most infamous biological invasions. Today we look at the Asian Ladybeetle, which Norwegian farmers were keen on importing into the country to use to control pest species that were damaging local crops.

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Our Responsibility Regarding Invasive Species (A Counterpoint to Mark Davis)

The Eastern Oyster, a species which has a high potential to spread throughout Norwegian waters, but little known ecological effect

The Eastern Oyster, a species which has a high potential to spread throughout Norwegian waters, but little known ecological effect (Image Credit: Chesapeake Bay Program, CC BY-NC 2.0)

Last week I posted an interview with Mark Davis, an invasion ecologist who has urged caution when rushing to eliminate invasive species from an ecosystem. Whilst I didn’t agree with absolutely everything Mark said, he makes some very important points about the language around invasive species and our understanding of them.

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The American Mink

The American Mink is pretty much a Norwegian mainstay these days. So what sort of impact have they had?

The American Mink is pretty much a Norwegian mainstay these days. So what sort of impact have they had? (Image Credit: Ryzhkov Sergey, CC BY-SA 4.0)

Fur farming isn’t a topic we’ve had much cause to touch on so far in this series. But today, we look at a species that was introduced specifically for that purpose, whose presence in Europe is disliked by ecologists and animal rights activists alike.

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Lessons From a Long History of Fish Invasions

The European Perch, a species brought for angling by earlier settlers (

The European Perch, brought for angling by earlier settlers, has had severe effects on a number of native Australian fish (Image Credit: Wikipedia Commons)

Transport pathways shape the biogeography of alien freshwater fishes in Australia (2018) Garcia-Diaz et al., Biodiversity Research, DOI: 10.1111/ddi.12777

The Crux

Invasive species are a problem in every type of ecosystem, be it by reduction of local diversity, or negative effects on a region’s economy or human health. Freshwater rivers and lakes are no exceptions to this. Invasive fish have impacts on local habitats which include outcompeting or just flat out eating local species, changing a habitat’s entire structure (say by clearing away aquatic vegetation or increasing pH levels) and the reorganisation of the entire population of a lake or river, from the birds that nest on the shoreline to the tiny planktonic species that are the base food source of the entire ecosystem. Once an invasive species is established, it can be impossible to remove.

So naturally, understanding where and how invasive species are likely to strike is of huge benefit. This paper tries to map that out, using Australia as a case study. It’s a great example; Australia has a long history with invasive species, and this study alone looks at 33 different types of invasive fish.

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The Alien Species List

The Greater Canada Goose, one of many species on Norway’s Alien Species List.

Guest post by Malene Nygård

Lately, alien species have gained a lot of attention, making headlines for all the wrong reasons. Headlines like ‘Alien species are floating on plastic to the Norwegian shore’, ‘Aggressive blind passengers threaten Norwegian blueberries’, and ‘Unwanted species crossing the boarder threaten Norwegian plants’ are example of headings covering newspapers just in the last year. But what exactly is an alien species, and what makes them so unwanted?

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