27 Jun 2016 Story Ecosystems and Biodiversity

Invasive species – a huge threat to human well-being

Human mobility has fundamentally altered the make-up and the character of the biological world, as more and more species, relocated from their natural home environments, have – as aliens – been introduced, either intentionally or unintentionally, into the homelands of other species. This co-mingling of species, on the increase ever since the age of exploration, has accelerated dramatically in recent times, with the advent of mass transportation, travel and trade … and the onset of full-blown globalisation. (“Invasive Alien Plants and their Management in Africa”, by Gordon Boy and Arne Witt – a UNEP-Global Environment Facility initiative)

Nairobi, 27 June 2016: People busy earning a living may react to the idea that invasive species pose a severe threat to biodiversity, and even national economies – with a yawn or a shrug.

But worrying evidence indicates that such species are causing untold damage and that swift action is needed. Governments need to galvanize interest and awareness.

“I bet that if we went to bed tonight with no invasive species anywhere, and woke up tomorrow morning to a sea of invasives and introduced pests eating all of our crops, most governments would declare state of emergencies,” says  Arne Witt of the Centre for Agriculture and Biosciences International.

Species that grow and reproduce quickly, and spread aggressively, with potential to cause harm, are given the label of “invasive”.

Invasive Alien Species (IAS), which can be plants, animals or pathogens, are introduced species (intentionally or unintentionally) that become established in a new environment, then spread in ways that are destructive to human interests and natural systems.

For example, in Ethiopia 82-95 per cent of sorghum yields are lost to Parthenium hysterophorus (Tamado and Milberg, 2004); Prosopis juliflora (“the Devil Tree”) invaded about 800,000 hectares in Ethiopia, 600,000 in Kenya, 1.8 million in South Africa and 5.6 million hectares in India. Invasive plant species can have huge impacts (e.g. on pastoralists) and force people off their land and into migration.

Just a few days ago The Guardian reported on a poisonous tropical lionfish that could be spreading through Mediterranean.

IAS have adverse effects on national economies, food security, human health, as well as biodiversity and habitat.

Economic costs of invasive plants and animals in the USA are estimated at $137 billion and in SE Asia at 33.5 billion per annum.

It is estimated that IAS cost the global economy over 5 per cent of global GDP in 2011. Compare that to estimates of 0.2-2 per cent of GDP for climate change (International Panel on Climate Change, 2014), and the scale of the problem becomes clearer.

Problem aggravated by the Internet?
IAS are everywhere - and still being introduced, advertised (to gardeners) or spread due to carelessness or ignorance, and the problem is being exacerbated by the on-line trade.

You can buy seeds of prohibited invasive plant species via e-Commerce from all over the world. For example, buyers in Australia obtained seeds of Mimosa pigra, yet the Northern Territory government spends $600,000 a year to eradicate this noxious weed from Kakadu National Park. “Safety filters”, by these firms, to prevent sales of noxious weeds are not working. A recent survey identified 94 advertisements for 44 banned species.

The United Nations Convention on Biological Diversity, hosted by UNEP, has called for tackling the e-Commerce/online trade in IAS, and UNEP invasive species expert Max Zieren highlighted the issue in a presentation to the National Seminar on Invasive Species Management in Indonesia, BICC, Bogor, West Java on 1 June 2016.

The European Union passed the “EU Regulation (1143/2014) on invasive alien (non-native) species” on 1 January 2015. It ”forbids possession, transport, selling or growing species deemed as of Union concern”.

Food security concerns
Reduced agriculture production is one of the biggest impacts and can affect food security.

Lantana camara invaded most pasturelands in India (13.2 million hectares) and poisoned cattle, and in Queensland, Australia (1985), it led to 1,500 animal deaths, reduced productivity and loss of pasture.

Insect pests such as Tomato Leafminer (Tuta absoluta) are recent and fast spreading, and very damaging to tomato production. The pest was inadvertently brought in from South America and has been in Europe and Africa since 2006. In Nigeria it forced a $200 million tomato processing factory to close.

Coffee plantations in East Java, Indonesia, recently lost 83 per cent of production due to four IAS.

“The cornerstone of biodiversity conservation – Protected Area systems – are increasingly becoming infested and threaten the survival of well know species such as Java Rhino or Asian Elephant, as well as affect a range of other functions like eco-tourism. If we do not act soon, all those millions and millions of investments already put in conservation will go to waste,” says UNEP’s Max Zieren. In Indonesia about 50 per cent of protected areas may be affected.

Key barriers to action

  • IAS are a gradual/hidden process; problems often develop years later
  • Economic costs not recognized – politicians not interested enough despite global costs estimated at $1.4 trillion per year
  • Low awareness where it counts most (decision-makers, corporate sector, aid agencies)
  • Lack of specifics on IAS in national policies, legislation and budgets
  • Science not investing enough in demonstrating the true impacts of IAS
  • Invasive species are already everywhere yet most agencies emphasize prevention instead of controlling their further spread

What can be done?

  • Focus prevention and control where it most counts and is most feasible – e.g. in our Protected Area systems, make budgets available
  • Go for cost-effective and environmentally friendly methods like bio-control combined with others such as integrated pest management
  • Identify new pathways of introductions (governments should act on e-Commerce)
  • Develop national and regional social marketing/communications campaigns;  integrate IAS into school curricula
  • Use champions, success stories to highlight economic and human costs; promote bio-control on TV; make the subject more “sexy”
  • Make IAS integral to national food production, health and development programming
  • Conduct national IAS censuses and estimate costs;
  • Tap into crowdsourcing techniques to gather information (use Smartphone apps, involve corporate sector, students)

Invasive species are crosscutting and a development problem – affecting attainment of various Sustainable Development Goals, not just biodiversity; much more research, investment and advocacy is needed in this area.

For more information, please contact: Max Zieren: [email protected]


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