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News in brief

3 Posts tagged with the invasive_species tag
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A Chinese mitten crab has been recorded in Scotland for the first time, posing a potential threat to local biodiversity and habitats.

 

The invasive crab species is already known to have populated rivers in the UK as far north as the Tyne, but this sighting in Glasgow's River Clyde confirms its migration over the Scottish border.

 

The Chinese mitten crab, named for the furry mats covering its claws, is one of the top 100 worst alien species in the world, according to the International Union for Conservation of Nature. It threatens biodiversity by competing for food, preying on native species and causing severe structural damage to riverbanks through burrowing.

Crabs on tour

 

The specimen found in the River Clyde, the remains of a female mitten crab, is the first recorded sighting north of the border.

 

The Chinese mitten crab (Eriocheir sinensis), is native to East Asia but is now found across NE Europe and the USA. It was first recorded in the River Thames in 1935, probably introduced by shipping. In the late 1980s the mitten crab began to disperse westwards along the Thames, and there are now well-established populations of E. sinensis in a number of Welsh and English rivers, as well as a single sighting in Ireland in 2006.

 

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The left claw of a male mitten crab (Eriocheir sinensis).

 

The International Maritime Organisation (IMO) has set out standards for the control and management of ships’ ballast water and sediments, in an effort to control the transport of species to non-native waters.

Potential threat to biodiversity

 

Mitten crabs may target the eggs of salmon and trout, according to recent research by Royal Holloway University of London (RHUL) student Jessica Webster and supervisors Dr Paul Clark (the Museum) and Dr David Morritt (RHUL).

 

Dr Clark sees the recent discovery as a major threat:

"An established River Clyde Chinese mitten crab population could pose an enormous environmental risk to the salmon and trout in this catchment (…) if this reported Clyde specimen came from a deliberate human release, the environmental authorities need to urgently consider what appropriate actions are required to prevent such introductions happening again in the future."

 

Dr Clark is studying the biology and behaviour of mitten crabs to better understand how we might control their migration and ultimately eradicate alien populations outside East Asia.

See live mitten crabs at Science Uncovered

 

As part of the Museum's annual festival of science on 26 September 2014, Dr Paul Clark and Dr David Morritt will be showcasing some live Chinese mitten crabs and talking about their work on the biology and behaviour of this problem species.

 

Come along to Science Uncovered to see these and a whole host of other specimens, take part in activities and meet Museum scientists.

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An Indian rust fungus has been released at several sites across England as a form of 'biocontrol' - using a natural enemy to control an invasive species, in this case the Himalayan balsam.

 

Introduced by Victorians as an ornamental plant, the Environment Agency now estimates that the Himalayan balsam occupies over 13% of river banks in England and Wales. It can reach over 3 metres in height and causes trouble by smothering vegetation, out-competing native plants and by adding to the risk of flooding by clogging waterways.

 

This week, the not-for-profit organisation CABI released the rust fungus in Berkshire, Cornwall and Middlesex after successful laboratory trials showed that it causes significant damage to Himalayan balsam but does not impact on native species.

 

The wet Bank Holiday weekend was a wash-out for some, but as Museum botanist Dr Mark Spencer explained, it was the perfect conditions for release: "the fungus does best in warm, wet conditions!"

 

Know your enemy

 

Dr Spencer has been advising on the project, which is headed by CABI with primary funding from Defra and the Environment Agency, and with contributions from Network Rail, the Scottish Government and Westcountry Rivers Trust.

 

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The Himalayan balsam, dominating the banks of the River Alt.

© Mike Pennington

 

The rust fungus, a natural enemy of the Himalayan balsam in its native lands in the foothills of the Himalayas, has been extensively tested as a natural control method. Conversely, using existing methods, the Environment Agency estimates it would cost up to £300 million to eradicate Himalayan balsam from the UK.

 

Selection of a suitable natural enemy and laboratory trials took eight years. If the rust is successful in the UK, Dr Spencer predicts it could resolve the problem of Himalayan balsam within a few years.

This is a really important step forward for the control of invasive species in Europe, I wholeheartedly support the decision to approve release. Project partners have already set up a monitoring programme to assess the spread of the fungus onto Himalayan balsam. If the fungus establishes itself at the trial sites there should be no need for additional releases, the fungus will spread naturally through the UK.

The licence to release the rust fungus is only the second of its kind ever issued in the UK, following the 2010 release of a specialist insect, Aphalara itadori, to control the plant Japanese knotweed.

 

Read more about invasive species in the UK:

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A section of the new Infrastructure Bill designed to control invasive species could end up harming important native species such as the barn owl and the red kite.

 

In an open letter to the UK Government published last week in Nature magazine, 24 leading scientists including Museum researcher Prof Geoff Boxshall called for the bill to be re-written. The letter states that, "If the bill is passed in its present form, it could lead to an irreversible loss of native biodiversity."

 

The potential problem lies in the way the bill defines a 'non-native' species. According to the letter:

The draft bill defines non-native species as those that are “not ordinarily resident in, or a regular visitor to, Great Britain”. This definition covers past native species that are now extinct, species that may become naturally established under a changing climate, and species listed in Schedule 9 of the Wildlife and Countryside Act.

Schedule 9 contains, among others, several species that have gone extinct in the UK and been reintroduced, such as the barn owl and the capercaillie (a type of grouse).

 

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The barn owl is one species that could have its status changed by the new bill.

© David Tipling Photo Library / The Trustees of the Natural History Museum, London.

 

The wording of the bill means that species slated for reintroduction, such as the European beaver and wolf, would be classed as non-native and their conservation threatened. Species naturally migrating from Europe as the climate changes, such as butterflies and other insects, would also be punished by the new definition.

 

Prof Boxshall thinks the definition needs to be changed:

The classification of native versus non-native is an ongoing matter for scientific debate, particularly in the face of climate change. By using such a simplistic definition, the government effectively bars the possibility of reintroduction of locally extinct species and adaptation to climate change.

 

Amendments have been suggested in the House of Lords to correct the problems in the legislation, but so far these have been rejected.