Module 1: what decision-makers need to know about invasive species Developing legal and institutional frameworks for invasive alien species

what decision-makers need to know about invasive alien species 2 what this module covers 1.what ‘invasive alien species’ and ‘invasion’ means 2.pathways for species introductions 3.impacts of IAS 4.problems of prediction and links to other environmental pressures 5.the importance of information and available international resources what decision-makers need to know about invasive species Module 1 laying the foundations for effective national frameworks Module 2 preventing biological invasions preventing biological invasions Module 3 responding to biological invasions responding to biological invasions Module 4 getting results: compliance, enforcement and liability Module 5 legal frameworks for cooperation beyond borders Module 6

many different terms – a complex area what are invasive alien species? an alien species is a species that has been introduced to a location (ecosystem or area) where it does not occur naturally an invasive alien species (IAS) is an alien species that causes (or has the potential to cause) harm to the environment, economies and/or human health

introductions are nothing new......but globalisation has led to massive expansion of opportunities for introductions

what type of species invade? from all taxonomic groups vertebrates (e.g. mammals, fish, birds, reptiles) invertebrates (e.g. insects, snails, worms) aquatic, marine and terrestrial plants (e.g. weeds, trees) micro-organisms (e.g. viruses, bacteria)

Process of Invasion 2. Establishment 3. Spread 1. Introduction – intentional or unintentional – survives but doesn’t spread (a) naturalisation – becomes part of new habitat’s flora/fauna (b) invasion – expands and impacts on species, ecosystems people and development

1. Introduction 2. Establishment 3a.Spread - Naturalisation 3b. SPREAD - INVASION the House Sparrow spreading and invading Tanzania over 90 years

Many IAS undergo a lag phase after initial establishment, and may remain unobtrusive before becoming invasive and spreading rapidly In some species (e.g. trees) this may be more than 100 years, in others (e.g. water hyacinth) it may be a few weeks Population size Time Carrying capacity Lag phase

Process of Invasion from Introduction to Consolidation (after Williams, 2003) IntroductionInvasion Consolidation habitat occupation changes during invasion

Invasions can thus be stopped at several stages: best is prevention = stopping introductions next best is eradication = destroying or removing a new invasion third is containment = stopping a new invasion from further spreading last (and most expensive and time-consuming) is management of established invasions + restoration of affected systems Sequence endorsed under Convention on Biological Diversity

how do species get moved around? Vectors – The specific mechanism by which a species is moved along a pathway (clothing, vehicle, boat hulls, ballast water, packaging, soil around plant roots...) e.g. a tourist carrying seeds is a vector in the pathway of international airline flights Pathways – The routes along which a species is moved or moves itself (roads, railways, air corridors, shipping lanes, rivers)... including trade itself

Shipping routes now reach every continent (even Antarctica) and air travel reaches most cities in the world

ballast water a major vector for unintentional introductions in the shipping pathway up to 14 billion tonnes of ballast water transported around the world each year an estimated – species may be present in ballast water at any given time Zebra mussels were introduced to the Great Lakes of North America in ballast water in the 1980s, and now cause severe economic impacts

introduction establishment spread naturalisation invasion direct & indirect causes of introductions direct causes introduction of species for commercial purposes e.g. aquaculture, seeds, crops, livestock, food, biofuels introduction of species for control purposes e.g. biocontrol, landscape restoration introduction of species for lifestyle and aesthetic purposes e.g. pets, ornamental plants, aquariums unintentional or accidental introductions e.g. contaminated imports, hitch-hikers in freight or luggage, ballast water, dumping indirect economic causes forces and conditions which determine trade, production and consumption practices and preferences e.g. expanding travel & trade, globalisation, subsidies to production, trade and investment incentives, market demand and consumer preferences, low fines, high reliance of economy on imports forces and conditions which determine land and resource use practices and preferences e.g. high reliance of economy on particular productions sectors, incentives to clear land and replace native species, price support to exotic monocrops, unclear institutions and property rights, lack of budgets and funding to conservation

introduction of species Some establish, naturalise and spread Movement by human action of a species outside its native range can result in introduction (into/within a country) Some establish, naturalise and spread

intentional introduction unintentional introduction for food, agriculture, forestry, horticulture, fisheries, hunting, ornamental and for pleasure... species that move with other imports as ‘hitchhikers’ or ‘stowaways’

impacts of IAS negative impacts on: ecosystems economies human health

ecological impacts direct predation/herbivory competition for resources/exclusion (e.g. light, food) transmission of pathogens and parasites alteration of micro-climate, nutrient availability, ecoystem cycles (energy, water, minerals, organics) disturbance to ecological processes (e.g. pollination) disruption of ecosystem services (e.g. flood attenuation) environmental degradation, facilitating further invasions

economic impacts estimated at 5% global GDP Direct costs Direct loss of crops, reduced yields Lost export earnings Loss of tourism revenues Management costs Indirect costs Impaired ecosystem services Damaged infrastructure Costs to natural environment and societal or cultural values

health impacts Direct impacts Disease Allergic reactions Injuries through stinging or biting Indirect impacts Providing a vector for disease

ECOSYSTEM SERVICES Supporting Nutrient cycling Soil formation Primary production … Provisioning Food Fresh water Wood and fiber Fuel … Regulating Climate regulation Flood regulation Disease prevention Water purification … Cultural Aesthetic Spiritual Educational Recreational … Security Personal safety Secure resource access Security from disasters Basic material for good life Adequate livelihoods Sufficient nutritious food Shelter Access to goods Health Strength Feeling well Access to clean air & water Good social relations Social cohesion Mutual respect Ability to help others Freedom of choice and action Opportunity to be able to achieve what an individual values being and doing CONSTITUENTS OF WELL-BEING Adapted from Millennium Ecosystem Assessment 2005 which results in changes in impact on the provision of invasions understanding, assessing and acting on invasives in the light of the changes in ecosystem services and human wellbeing they give rise to economic analysis Millennium Ecosystem Assessment /Emerson & Howard

Lantana camara is a classic IAS which (after 160 years) is still spreading across Africa and invading new lands - as well as in Australia, Asia and North America Lantana replaces native vegetation and pasture, is poisonous to livestock and harbours tsestse flies and rats

an example of spread and invasion impacts In 1974 there was an occasional plant of Mimosa pigra on the edges of the Kafue River Kafue Floodplain, Zambia, dry Kafue Floodplain flooded 1974 The Kafue Floodplain was home to many wild animals and plants + cattle grazing, fishing, conservation & tourism

Mimosa pigra (continued) A heavy flood in 1981/2 brought a few plants of Mimosa pigra on to the floodplain (which was a new ecosystem changed by a dam upstream) 1982

Mimosa pigra (continued) After a slow start in the late 1980s, M. pigra began to spread By 2000 it was covering a few hundred hectares 2001

Mimosa pigra (continued) By 2007 it was growing up to 4m high and covering 3,000 hectares …. and excluding almost every other plant and most animals …. 2007

Mimosa pigra continued Today: no livestock no fisheries no tourism on this part of the Kafue Floodplain costs to livelihoods & production 3,000 ha of an available 12,000 ha are now covered

invasion impacts – human development Water hyacinth affecting Kafue Gorge Dam and hydropower station, Zambia ( photo M. Mumba )

impacts on production (eco)systems ecosystems, native or cultured, that are used for food and commodity production can also be invaded by alien species forestry, fisheries, agriculture, aquaculture parasitism, pathogenesis, predation, competition, exclusion and destruction of productive systems are all recorded – most known from farming, horticulture and livestock production Tall trees of Senna spectabilis from S. America replacing native forest in Uganda

“Invasiveness” of an alien species what makes a good invader? rapid growth rate great dispersal characteristics large reproductive capacity broad environmental tolerance effective competitor with local species all invasive plants can be called “weeds” BUT not all weeds are invasive species Lianes in Seychelles

current and future trends human activities are changing natural ecosystems and making them more susceptible to IAS globalisation land-use change climate change

invasives and climate change climate change is upon us - although not exactly predictable in area or extent climate change will make ecosystems more vulnerable to invasions invasive species are already “taking advantage” of changed climatic conditions and expanding to the detriment of local species, habitats and ecosystems thus we must be prepared for ecosystems affected by climate change to be further invaded and we must develop tools to predict and prevent these extra invasions

causes and effects of IAS are international or regional IAS management and control supported by bilateral, regional and global instruments and guidance (see Modules 2 & 6)

emerging principles of IAS management the precautionary principle the principle of preventive action the ecosystem approach sharing of information user-pays principle cross-sectoral approach to management Parties to “prevent the introduction of, control or eradicate those alien species which threaten ecosystems, habitats or species” (Art.8(h)) Convention on Biological Diversity 1992 (CBD)

Sharing of expertise and information is crucial Types of information to be shared? Inventories and databases Incident lists and case studies Potential threats to neighbouring countries Information on taxonomy, ecology and genetics of IAS Prevention and control methods where available National and regional guidelines and measures Many IAS databases accessible electronically EAFRINET The eastern Africa LOOP of BioNET-International

Some GISP products that can help