Invisible parasites are spreading in Norway

Norwegian nature is not only attacked by cottage fields and wind turbines. The list of new alien species shows a huge influx of new species. Some are almost invisible.

New to the list of exotic species that breed in Norway is the Harbor Spud or Japanese sea urchin. This species is in the higher risk category and has spread violently in a few years. Photo: Torbjørn Brekke/Artsdatabanken/CC BY 4.0

1,400 exotic species have spread to the Norwegian landscape. Several hundred more may arrive at any given time.

One day in December of 2020, an alarm bell went off.

Japanese vomiting came as stowaways

Then the harbor scattering was discovered at Engøysundet in Stavanger. It is actually called Japanese sea urchin.

The alarm should go off a few times each week. Every day, frightening species are involuntarily imported into Norway.

The sticky sea urchin resembles vomit that floats. It spreads very quickly and has destroyed benthic life in many parks around the world. It now covers more than half of the Engøysundet sea floor. On its way, it suffocates norwegian species and completely changes the ecosystem.

Sørhare is already popular in Østfold. It probably originated from Sweden, where it was introduced in the 19th century. Its origin is from southern Europe and western Asia. It poses a very high risk to the Norwegian Forest Hare.

1 out of 3Photo: Hans Hillewaert/Artsdatabanken/Licensing CC BY-SA 4.0

In the past three years, it has been found in several places in western and southern Norway. This summer he was found in Koster, not far from the entrance to the Oslo Fjord.

If it spreads out into the fjord towards the capital, it could be a deathblow for a fjord already in the middle of an ecological collapse.

Havnespy may have come to Stavanger as a stowaway on a boat.

Many exotics come this way. They creep into the countryside with ballast water in a boat or in a clump of soil around the flower you’re growing in the garden.

Others, such as Pacific oysters, have escaped from farms. Lilacs creep out of our gardens into nature. There they overtake endangered Norwegian shrubs and flowers. Chives are running away from the kitchen garden.

The spore-forming fungus Aphanomyces astaci, also known as crayfish plague, could reduce populations of the red-listed and endangered Norway noble lobster. He arrived here with a lobster spread. It also spreads with tropical shrimp used in aquariums, and survives even if shrimp die in cold Norwegian waters.

1 of 2Image: Bram Koese / Artsdatabanken / License CC BY-SA 4.0

800 new species evaluated

On Friday, ArtsData Bank introduced the new listing. The previous one came in 2018. Since then, 800 new species have been assessed for risk. Many species that five years ago were called doorstep species have now made the leap into our nature.

What’s called alien species We humans have been sprouted out in nature where they don’t belong. This species poses one of the biggest threats to Norwegian nature.

The Exotic Species List should not be confused with the Prohibited List. There is an overview of plants that are prohibited for import and sale in Norway.

Olga Helmo led the work on the new list:

– It’s important to monitor all exotic species, especially those considered high-risk, she says.

High-risk species overtake and displace native Norwegian species, many of which are endangered. It can also have a negative impact on endangered habitat types. Alien species can interbreed with related species in Norway and contaminate the genetic material, says Helmo.

40 new products in five years

In recent years, Artsdata Bank has done a lot of work mapping out the so-called door sill species. Hundreds of species are found in our neighboring countries. And at any time they can accompany garden plants imported to Norway.

They are on our doorstep. The category also includes species that are currently found only in gardens and parks, but not in nature.

But this step is short. As many as 42 species that only five years ago were considered passerine species are now covered in Norwegian nature.

One of them is the devil’s reddish tongue. It is an algae (kelp) that can grow up to three meters in length.

The Asian goat is native to Asia. In 2004, it was discovered in France and spread to several European countries. This goat is a predator and a threat to the beekeeping industry. If it comes to Norway, it will also be a threat to our pollinating insects.

1 out of 3Photo: Charles J. Sharp / Artsdatabanken / License CC BY-SA 4.0

An important reason why so many new species have been able to settle here is climate change. This means we have shorter winters and higher temperatures year round.

A total of 1,134 door jamb types were evaluated on this year’s list. This is an increase of 800 compared to 2018. Experts believe that this species will multiply in the Norwegian landscape within the next 50 years.

The authorities are trying to gain knowledge in order to introduce countermeasures early. Once the type is established, it is usually too late.

Olga Helmo isn’t surprised by the rush of new exotics: – But outright global trade brings many new species into the country every day. Many of them come from areas biologically similar to Norway. With climate change, she says, many of them will have the ability to establish themselves here.

A dead specimen of a house shrew was found in Jæren in 2012. In the following years, many specimens of this species were found. The house shrew is one of the new species included in the list of exotic species and is indicated as a species of high risk to the Norwegian nature. Photo: Balles2601 / Artsdatabanken / License CC BY-SA 4.0

The Invisible Scoundrels

Some are easy to spot. Like the brown wood snail or the Pacific oyster.

But some of the newcomers are so young they’ve gone under the radar. In this year’s list, 29 such little things have been added. Among other things:

Three different parasites.
Flat brushes are found inside Pacific oysters.
A small shrew house recently discovered in Jæren.

Seven of these 29 have a high or very high risk to nature. They can cause harm to animals and plants. This, in turn, can lead to significant economic losses in agriculture, among other things.