The aliens have landed

Click:HP2202

The aliens have landed

Introducing a new species may seem like a good idea, but it can bring disease and disruption that costs huge sums to deal with.

By

2/10/10, 9:12 PM CET

Updated 4/12/14, 7:04 PM CET

The first recorded arrival in Europe of Fallopia Japonica, better known as Japanese knotweed, was in 1823 when a Dutch gardener with a taste for the exotic brought it home from his travels. 

Click Here: Cheap FIJI Rugby Jersey

The plant was soon sprouting up in public parks and gardens all over western Europe and by the end of the century had travelled as far east as present-day Latvia. But many rue the day that this hardy shrub was first put into European soil. It is now classed as weed. Famed for crowding out native vegetation, especially in Germany’s Black Forest, the Japanese knotweed has strong root systems that can threaten flood defences and foundations, and is known as one of Europe’s 100 worst invasive species.

Invasive species are alien plants and animals that flourish in their new environment, often at the expense of locals. Alien species have always existed but today invasive species are more numerous and more expensive to eradicate.

There may be as many different paths to EU soil as there are alien species. Some non-native species are brought to the EU for economic reasons, such as non-native conifers or minks intended for fur farms.

Some are brought to Europe as pets or bait for fish, while others are stowaways, such as crabs that hitchhike on the hulls of ships or insects that travel in used-goods consignments. Ballast water from ships is also a major carrier of newcomers: 1,000 non-native species can be found at an average European port.

Health worries

These new arrivals can cause havoc. They may out-compete native species for food, as the Canadian beaver and American squirrel have done. Other species, such as ornamental carp, bring new diseases that kill or sicken local species, while some invaders cause problems for human health. The giant hogweed causes allergies and skin burns. Alien plants crowd out local species and may contribute to soil erosion.

The cost of repairing the damage caused by invasive species was put at €12.7 billion in 2008, according to the European Commission, although this is regarded as a conservative estimate. Alien species are an even bigger problem in the United States, costing $120bn (€88bn) each year and threatening 42% of native species.

The European Union is increasingly concerned. Last year environment ministers called for the Commission to draw up a strategy on invasive species.

They said that this should contain measures on preventing the spread of invasive species, early-warning systems, as well as policies to monitor new arrivals and efforts to restore native biodiversity “as far as feasible”.

Piero Genovesi, chair of the invasive species specialist group at the International Union for the Conservation of Nature (IUCN), fills in some of the gaps on how such a strategy might work. “Prevention should be the first line of defence,” he says. Countries also need to set up systems “to enhance the rapid detection of new invasions and rapidly remove these species”.

This is “much less complex and costly than waiting for the species to become established and then starting a permanent control activity”.

Eradications

Genovesi says that the US offers the EU some lessons. In California, specially trained farmers detect alien weeds, which are then removed by a state agency. At least 17 species have been removed before they could damage agriculture.

Getting rid of alien species is far from impossible. “There have been over 1,000 eradications in the world and, with adequate planning and resources, it is possible to remove even invertebrates, such as ants, from quite large areas,” says Genovesi. “Total removal is in fact the only permanent solution to a species invasion.”

He thinks that Europe has a lot to learn from other parts of the world. New Zealand and Australia are “the countries with the most stringent and effective policies”, he says, citing their tough biosecurity measures, which prevent the arrival of almost 90% of potential invaders.

Other countries, such as South Africa or Mexico, are improving their ability to deal with invasive alien species, Genovesi says.

“Unfortunately, Europe lags behind other areas of the world in this context, but there are encouraging examples of effective actions carried on at the regional and national level.”

Authors:
Jennifer Rankin 

Leave a Reply

Your email address will not be published. Required fields are marked *