Understanding the Impacts of Invasive Alien Species on Economies and Ecosystems
This module explores the far-reaching impacts of Invasive Alien Species (IAS) on economies, environments, and societies. By the end, you will understand the different types of impacts, associated costs, and examples of problematic species. Economic impacts in the U.S. alone are estimated at $137 billion annually, affecting agriculture, trade, and infrastructure. IAS disrupt ecosystems, cause biodiversity loss, and have social implications, including health and recreation. Management efforts require significant investment, highlighting the ongoing challenge of IAS worldwide.
Understanding the Impacts of Invasive Alien Species on Economies and Ecosystems
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Presentation Transcript
MODULE 2 Impacts of IAS
Learning Outcomes • By the end of this module you should be able to: • understand the different types of impacts • know the costs associated with IAS • give examples of problematic species • identify the indirect effects of IAS
Categories of IAS impacts • Economic • Environmental • Social
Economic impacts • In the US the economic costs of invasive plants and animals are estimated at US$137 billion per year.
Economic impacts • These include: • Primary production • Trade • Infrastructure damage • Management • Other sectors
Primary production • Agriculture • up to 40% of global agricultural production lost due to IAS • up to 49% of production in Africa
Primary production • Leafy spurge • competes with native plants • increases erosion • toxic to animals • causes skin irritation
Primary production • European rabbit • annual cost to Australia’s agricultural production is US$373 million • feeds on many crops, including wheat and livestock forage • causes erosion
Primary Production • Field rat • Feeds on harvested grain and destroys crops • In Indonesia consumes 17% of rice crop
Forestry • IAS impacts include: • timber losses • cost of herbicides and pesticides • worldwide cost of $100 billion per year
Primary Production • European gypsy moth • causes extensive defoliation • eats the leaves of approximately 500 plants and trees • a major pest in North American forests
Primary Production • Comb jelly • comprises up to 95% of the biomass in the Black Sea • was responsible for the collapse of the anchovy fishery, which was worth $US 250 million/year
Primary Production • Sea lamprey • predate upon sport fish in the Great Lakes of North America • extract blood and fluids from host fish
Trade • Export restrictions for IAS infested countries • Hawaii • loss of millions of dollars in fruit exports when fruit flies discovered
Tourism • Siam weed (Chromolaena odorata) • a threat to conservation and ecotourism • invades natural areas • reduces biodiversity • compromises game-viewing in nature reserves and national parks
Tourism • SARS outbreak • caused $17 billion loss to China’s tourism industry in 2003
Property / Infrastructure • Brown Tree Snake • causes $US 1-4 million damage to power lines on Guam • power outages every 3 days on average
Property / Infrastructure • Zebra mussel • clogs water intakes and discharge pipes • competes with native mussels • cost of control is $US 10 billion over 10 years Fouled pipe
Property / Infrastructure • Formosan subterranean termite • infestations weaken the structure of houses • cause $US1 billion/year of damage in the United States
IAS Management • Globally, billions of dollars are spent to prevent, eradicate and control IAS impacts • Although the costs of prevention are often high, they are minor compared to the costs if an IAS were to become established
Smallpox AIDS ribbon Cholera Social Impacts • Human health • introduced infectious diseases can have a devastating impact • AIDS, smallpox, cholera
Social Impacts • Recreation • invasive plants interfere with recreational activities in parks and protected areas
Culture • Invasive species can impact on the cultural values and activities of an area • Examples: • - loss of native grasses used in basket making • - the loss of species harvested for ritual
Mile-a-minute weed overgrowing a fence in Palau Livelihoods • Loss of biodiversity due to IAS affects peoples’ livelihoods
Environmental Impacts • Ecosystems and biodiversity • within an ecosystem all species are connected • a disruption to one species can affect a whole range of other species
Species level impacts • IAS can affect native species by: • changing their abundance • changing their geographical range • causing local or global extinction
Wasp feeding on honeydew Ecosystem level impacts • IAS can change the balance and structure of ecosystem • common wasps have invaded New Zealand beech forests • they monopolize high-energy honeydew produced by scale insects • native species are unable to feed on this important resource
Black petrel killed by feral cat Processes • Predation • Herbivory • Disease (pathogens)
Processes • Physical processes (fire regimes, nitrogen cycles) • Competition • Hybridisation • Parasitism The mallard duck hybridises with many native duck species
Concluding remarks • Many IAS are detrimental to the economy as well as human health and the environment • Unlike other environmental ‘pollutants’ IAS have an increasing impact over time
Summary • Invasive Alien Species have had enormous negative impacts. • IAS are found in nearly every habitat and occur in all major taxonomic groups. • Invasive species can have adverse economic, social and ecological impacts. • Billions of dollars are spent annually to prevent, control and manage IAS. • The introduction of an IAS can cause major ecosystem changes.
