The cost of invasive non-native species

CABI Europe – UK completed the report ‘The Economic Cost of Invasive Non-Native Species on Great Britain’ in 2010  which investigated the financial and economic economic impacts that invasive non-native species may have on the British economy.

They estimated the potential cost at a total of £1.7 billion annually (£1,291,461,000 to England, £244,736,000 to Scotland and £125,118,000 to Wales).

Another report completed by the European Environment Agency (EEA Technical report, No 15/2012) estimates the cost to Europe, of damage and control of invasive non-native species, exceed €12 billion annually.

These costs are accrued through a variety of different means:

  1. The direct cost of treatment (e.g. treatment to ensure canals remain navigable or to maintain infrastructure like railways and buildings).
  2. Direct losses in trade or investment (e.g. lost in trade of oak trees due to oak processionary moth)
  3. Reductions in crop yield, although this is not as relevant for London.
  4. Losses in ecosystem services
  5. Direct damage caused by the invasive species (e.g. damage to forestry and vehicles caused by deer).
  6. Cost to human health and the cost of health treatment (e.g. giant hogweed, oak processionary moth)

Unique to London

Costs associated with invasive non-native species are usually high where humans and the species interact. This is usually because there is a need to mitigate the impacts that those species have on our activities. London is a highly urbanised centre with a large population making the costs to London potentially higher.

The report completed by CABI Europe – UK includes some costs that are unique to London, specifically in relation to costs associated with ring-necked parakeets (Psittacula krameri) and monk parakeets (Myiopsitta monachus). These species are known to damage buildings and human-made structures, the cost of which is thought to be £60,000 annually. In addition the current estimate of the cost of bird strikes at London airports caused by ring-necked parakeets is £17,500 annually. And with London’s airports spending £125,000 annually on reducing bird strikes, there is a concern that increases in these populations will see this cost rise (CABI, 2010).

Lessons for the Future

The highest costs are usually associated with management and treatment meaning we need to focus effort on prevention and early eradication where possible.

  • As invasive non-native species are increasing their distribution and effects are likely to increase.
  • The most cost effective way to manage an invasive species population is to treat it early.
  • The costs mentioned in the CABI Europe – UK report only represents the direct costs. The indirect costs could also be significant.
  • Invasive non-native species have the largest effect on the agriculture and horticulture sectors, with 67% of the total estimated cost. We have a responsibly to manage any source or new populations that may affect remaining outlying areas.