Invasive Species

200767767 Elizabeth Audrey Clemente

AN ALIEN SPECIES WHOSE ESTABLISHMENT AND SPREAD THREATEN ECOSYSTEMS, HABITATS OR SPECIES WITH ECONOMIC OR ENVIRONMENTAL HARM.

Alien Species S

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species, subspecies or lower taxon, introduced outside its natural past or present distribution; includes any part, gametes, seeds, eggs, or propagules of such species that might survive and subsequently reproduce not all alien species (also known exotic, nonindigenous, or non-native species) are invasive may be harmless and beneficial in their natural surroundings, but can totally devastate different environments; worldwide introduction of alien species have exacted serious problems in their respective host ecosystems, such harmful alien species are bioinvasive species

What makes bioinvasion different?

"Because it brings the intelligence of evolution to bear, bioinvasion is a kind of 'smart' pollution. Compared to living things, chemical spills are 'dumb‘– they are inert, they cannot reproduce and they tend to dissipate over time. But when an exotic species establishes a beachhead, it can proliferate over time and spread to new areas. It can also adapt—it tends to get better and better at exploiting an area's resources, and at suppressing native species." — Chris Bright

For an alien species to become invasive, it must arrive, survive and thrive. Successful Species

Unsuccessful Species

a.) Large native range

a.) Small native range

b.) Abundant in original range

b.) Rare in original variability

c.) High genetic variability

c.) Low genetic variability

d.) Associated with humans

d.) Not associated with humans

e.) Female able to colonize alone

e.) Female alone unable to colonize

f.) Gregarious

f.) Solitary

g.) Vagile (able to move freely)

g.) Sedentary

h.) Broad diet

h.) Restricted diet

i.) Short generation time j.) Shift between r and k strategies

How do they arrive and proliferate? When an invasive species enters a new habitat unaccompanied by its natural enemies, it often benefits from "ecological release" that allows the species to reach much higher population densities than would occur in its natural range where it is constrained by various predators and competitors. Example: Climate Change

deliberate introductions crop plants farm animals fish and shrimp for aquaculture decorative plants pets biological control organisms

Simplicity to produce, versatility, undemanding feed requirements, fast growth rate, relatively higher resistance to disease among others, available throughout the year Increase fish production to obtain a cheap source of protein Gain in foreign exchange through export Improve socio-economic conditions of small-scale fishermen Increase livelihood and employment opportunities for rural populations Overcrowding, stunting, high organic loading Endangers the world's smallest freshwater fish, the dwarf goby (Pandaka pygmaea Consumes zooplankton, phytoplankton, and algae resulting to damage in the ecosystem as well as eradicates cichlids causing internal erosion in lakes

Development Assistance & Biofuels development Parthenium weed through Biofuel production, cereal grain shipments for particularly for biodiesel: famine relief to Ethiopia bamboo, false flax, Post-disaster recovery and canola, Barbados nut, restoration efforts also coconut, horseradish tree require long-term and castor oil bush. monitoring given the frequent use of hardy, fast-growing species to stabilize/re-establish coastal areas and tree Given that food security priorities cover frequently take precedence of environmental

issues, the current and potential impacts of alien species are typically either overlooked or ignored

Eugene Schieffelin (New York, 1890)

 Planned to import every species of

bird mentioned in the plays of English dramatist William Shakespeare  European starlings (referred to in Henry IV)  Within 50 years, starlings had colonized the entire North American continent. Starlings roost in raucous flocks of up to hundreds of thousands: soiling pavement, damaging buildings, and fouling parks and playgrounds. Occasionally their droppings spread disease. These also strip grain, fruit, and vegetable crops and consume feed spread for livestock. Further, these aggressive invaders drive out native bird species, particularly bluebirds, flickers, martins, and wrens

Ornamental exotic plants and animals

 Used for large scale landscape

architecture or now, purchased through eBay! or the internet,  May increase the diversity of species locally; but, then the introduced species can take over, crowd out or kill the native indigenous species, and in some cases cause extinctions of particular species of plants and animals.  Just in Mt. Makiling, one can see the invasive vine, Skyflower smother other trees’ canopies, blocking sunlight and even air.

Accidental introductions  contamination with

various trade commodities  ship ballast which daily transfer millions of aquatic organisms throughout the world  airline passengers, cargo and the aircraft themselves  military aviation should also be regarded as potentially a larger threat given the hurried and frequently unregulated movement of equipment and personnel across a wide range of habitats

What are their Effects? 

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Outcompete natives—for nutrients, light, or water in the case of plants, or for food, shelter, or nesting sites among animals Alter the local environment that the site is no longer suitable for the natives Crossbreed with native species, thus damaging native populations through genetic invasion Change the nature of the ecological processes that provide clean air, pure water, fertile soil, natural pest and disease controls—processes often referred to as ecological life support services.

Threatening Food Security S S S S

Weeds – parthenium Crop viruses – whitefly Insect pests – white cassava mealybug and larger grain borer Introduction of Argentine golden apple snail into Asia for culture as a high-protein food source for domestic consumption, as well as for export. The species soon made its way to rice fields, where the animals voraciously consumed young rice plants. By 1990, the costs of snail invasion in the Philippines alone were between US$425-1,200 million, excluding non-market damages to human health and ecosystems which reduced the efficiency of rice production.

Economic Costs

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Losses to crops, pastures and forests, unemployment, damaged goods and equipment, power failures, food and water shortages, increased rates and severity of natural disasters, disease epidemics, and even lost lives CONSERVATIVELY estimated to be in the hundreds of billions of dollars Does not include valuation of species extinctions, losses in biodiversity, ecosystem services and aesthetics Examples: Asian Papaya Fruitfly, Nonnative rats, Asian Longhorned Beetle

second greatest threat to biological diversity contributes to habitat loss 90% of all animals that have become extinct since 1800 were island birds, and 90% of these fell victim to invasive species directly threatened by predators such as rats, cats and mongooses indirectly, by loss of habitat and food such as by

Global Homogenization: Threat to Biodiversity

Risk to Human Health

Ecological Impacts

 Bubonic plague – invasive

 Disturbing the operation of the

species of rat  1991. First cholera epidemic in the western hemisphere in more than 100 years, sickening 1 million people and killing 10,000.  Asian tiger mosquito through shipments – a series of encephalitis, yellow fever, and dengue fever.  To note, $6.5 billion a year accounts for medical care and lost wages and productivity due to human diseases caused by nonnative species.

hydrological cycle, flood control and water supply, waste assimilation, recycling of nutrients, conservation and regeneration of soils, pollination of crops, and seed dispersal  Dams – increased sedimentation or change in water levels  South African Cape Floral Kingdom. Loss of 30 percent of the region's water supply, increased fire hazards, and threatens native biodiversity.

What The World Is Doing

Early detection, assessment, prevention and control are the measures undertaken to manage the problem of invasives. Article 8(h), Convention on Biological Diversity "to prevent the introduction of, control or eradicate those alien species which threaten ecosystems, habitats, or species"

worst aquatic weeds in the world, growing so rapidly they double in 12 days - and seeds can survive for 30 years become so dense they prevent sunlight and oxygen from reaching water and submerged plants, crowd out other native aquatic plants block waterways, cause rivers and streams to change course, and interfere with boating, swimming and fishing decline in fish species and reduced water levels which brought on notable local

eradication: water hyacinth

From a destructive weed to a useful and beneficial plant: Natural water purification Fertilizer Energy producer Animal feed

Extinction is irreversible, but there is a growing realization that biological invasions themselves can sometimes be reversed.

Every alien species needs to be considered potentially invasive, until convincing evidence indicates that it presents no such threat

Mechanical Control Chemical Control Biological Control Habitat Management Integrated Pest Management (IPM) Gender-bending Chemicals

Eradication is often a large, uncontrolled experiment, and we should expect unforeseen outcomes

Controlling problem species often requires application of pesticides and mechanical controls that are harmful to non-target species The development of pesticide-resistant strains of pests, diseases and weeds may reduce the effectiveness of the chemical management option for their control The species used for biological control may in turn become invasive