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Aliens Within


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How cute animal and vegetal species can become pests when acting as aliens in new environment

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Aliens Within

  1. 6. We will use this high tech monitor to check on a few vegetal and animal species that might well act as « aliens » outside their original environment
  2. 7. We'll locate these Alien species on the world map, more specifically the places where problems occur with them
  3. 8. These screens will display image and basic information on these species
  4. 9. These gauges inform you on: > Invasion Stage : it represents the level of spreading and colonising of these species > Impact : it shows the level of threat these species have on their new environment
  5. 10. … but first: What are Alien species? The term is used in reference to the origin criterion, as a synonymous of exotic or non native. It refers to an organism whose presence in a given area is due to intentional or accidental introduction by man
  6. 11. An alien species can be considered as acclimatised if it is able to survive for a long period of time in its new environment. It is considered as naturalised as soon as it is able to reproduce consistently in the wild and sustain populations over several life-cycles without direct intervention by man (= self-perpetuating populations).
  7. 12. Finally, an alien species is considered as invasive when it is naturalised and able to increase population size, to disperse widely in the environment and to colonise semi-natural habitats.
  8. 13. Let's see some of these species ...
  9. 14. Alien Name: Caulerpa Taxifolia Common Name: Killer Algae Type: Alga Cause: Human Mistake
  10. 15. Alien Name: Caulerpa Taxifolia Common Name: Killer Algae Type: Alga Cause: Human Mistake The Killer Algae Caulerpa taxifolia is a species of seaweed, an alga of the genus Caulerpa. Native to the Indian Ocean, it has been commonly used as ornamentation in aquarium installations around the world. The alga has a stem which spreads horizontally just above the seafloor, and out of this stem grow vertical fern-like pinnae, whose blades are flat like yew, hence the species name "taxifolia" (the genus of yew is "Taxus"). The alga produces a large amount of a single chemical that is toxic to fish and other would-be predators. This is in contrast to other plants which produce a variety of toxins, but in reduced amounts. It appears that, in 1984, this seaweed was accidentally released into coastal waters of the Mediterranean Sea just below the Oceanographic Museum of Monaco. It was claimed that caulerpa had grown to have now spread over more than 13,000 hectares of seabed. A belief arose that it was preventing other plants from growing, leading to the nickname "Killer Algae". The plant began to spread between ports along the Mediterranean coast. C. taxifolia has been discovered off the coasts of Australia and the United States, though none of those encroachments have been anywhere near the scale of what is happening in the Mediterranean. The appearance off the California coast was most probably caused by an aquarium owner improperly dumping the contents, allowing C. taxifolia to flow through a storm sewer into the lagoon where the invasion was discovered. California has since passed a law forbidding the possession, sale or transport of Caulerpa taxifolia within the state. In July, 2006, the alga had been declared eradicated from the two Southern California locations
  11. 16. Alien Name: Lates Niloticus Common Name: Nile Perch Type: Fish Cause: Human Introduction
  12. 17. The Nile Perch Case The Nile perch (Lates niloticus) is a species of freshwater fish. It is widespread throughout Africa, being native to the Congo, Nile, Senegal and other river basins. Nile perch have been introduced to many other lakes in Africa but is now considered as one of the world's 100 worst invasive species. The state of Queensland in Australia levies heavy fines on anyone found in possession of a living Nile perch, since it competes directly with the native Barramundi, which is similar but does not reach the same size as the Nile perch. The species is of great commercial importance as a food fish. The Nile perch is also popular with sport anglers as it attacks artificial fishing lures and is also raised in aquaculture. The introduction of this species to Lake Victoria is one of the most commonly cited examples of the negative effects invasive alien species can have on ecosystems. The Nile perch was introduced to Lake Victoria in East Africa in the 1950s, and since then it has been fished commercially. It is attributed with causing the extinction or near-extinction of several hundred Alien Name: Lates Niloticus Common Name: Nile Perch Type: Fish Cause: Human Introduction native species. The alteration of the native ecosystem has also had disruptive socioeconomic effects on local communities bordering the lake. Large-scale fishing operations have displaced many local people from their traditional occupations in the fishing trade. The introduction of Nile perch have had additional ecological effects on shore. Nile perch has a high fat contentand need to be smoked to avoid spoiling. This has led to an increased demand for firewood in a region already hard-hit by deforestation, soil erosion and desertification.
  13. 18. Alien Name: Apis Mellifera Scutellata Common Name: Killer Bee Type: Insect Cause: Human Mistake
  14. 19. The Killer Bee The Africanized bee in the western hemisphere descended from 26 Tanzanian queen bees accidentally released by a replacement bee-keeper in 1957 near Rio Claro, Brazil from hives operated by biologist Warwick E. Kerr, who had interbred honey bees from Europe and southern Africa. Hives containing these particular queens were noted to be especially defensive. Kerr was attempting to breed a strain of bees that would be better adapted to tropical conditions (i.e., more productive) than the European bees used in South America and southern North America. The hives from which the bees were released had special excluder grates which were in place to prevent the larger queen bees from getting out but to allow the drones free access to mate with the queen. Unfortunately, following the accidental release, the African queens eventually mated with local drones, and their descendants have since spread throughout the Americas. The Africanized hybrid bees have become the preferred type of bee for beekeeping in Central America and in tropical areas of South America because of improved productivity. However, in most areas the Africanized hybrid is initially feared because it tends to retain certain behavioral traits from its African ancestors that make it less desirable for domestic beekeeping. These hybrid bees are Alien Name: Apis Mellifera Scutellata Common Name: Killer Bee Type: Insect Cause: Human Mistake aggressive bees that defend their nest from intruders up to 50 feet away by stinging in the hundreds and chasing intruders up to a mile. They have caused deaths of pets, livestock, and even people, giving them their "killer bee" nickname. People and other animals are usually killed only if they are unable to get away. Its largest impacts are economic and ecological. They affect the beekeeping industry by competing with native bee species, causing them to produce less honey and taking over the bees nest by killing its queen and replacing it with their own.
  15. 20. Alien Name: Heracleum Mantegazzianum Common Name: Giant Hogweed Type: Plant Cause: Human Introduction
  16. 21. Giant Hogweed Giant Hogweed (Heracleum mantegazzianum, also giant cow parsley) is a plant in the family Apiaceae, native to the Caucasus Region and Central Asia. It may reach 2-5 m (rarely to 7 m) tall. Many foreign plants were introduced to Europe in the 19th century, mainly for ornamental reasons. A few have become aggressively dominant, creating serious problems in some areas. It has also spread in the northeastern and northwestern United States and central Canada. It is a pernicious invasive species in Germany, France and Belgium, overtaking the local species. The enormous height and leaf area of the giant hogweed enable plants to overtop most indigenous herbaceous plant species. In dominant stands up to 80% of the incoming light is absorbed by it, such that other light demanding species will be suppressed. Giant hogweed may reduce species richness and change the composition of indigenous plant communities. Besides the ecological problems, tall invasive hogweed species also represent a serious health hazard for humans. Giant Hogweed is a phototoxic plant. Its sap can cause phytophotodermatitis (severe skin inflammations) when the skin is exposed to sunlight or to UV-rays. Children should be kept away from Giant Hogweed... yet it resembles Garden Angelica (Angelica archangelica) which has been used from the 10th century as medicinal plant and is used as a flavoring agent for its ... NOT TO CONFUSE neither with Conium, an highly poisonous member of the family. Although when Angelica emits a pleasant perfume, when crushed, the leaves and root of Conium emit a rank, unpleasant odour. Alien Name: Heracleum Mantegazzianum Common Name: Giant Hogweed Type: Plant Cause: Human Introduction
  17. 22. Alien Name: Bufo Marinus Common Name: Cane toad Type: Amphibian Cause: Human Introduction
  18. 23. Alien Name: Heracleum mantegazzianum Common Name: Giant Hogweed Type: Plant Cause: Human Introduction Alien Name: Bufo Marinus Common Name: Cane toad Type: Amphibian Cause: Human Introduction Cane Toads Originally, cane toads were used to eradicate pests from sugar cane, giving rise to their common name. The cane toad has many other common names, including "Giant Toad" and "Marine Toad"; the former refers to its size and the latter to the binomial name, Bufo marinus. Before the early 1840s, the cane toad had been introduced into Martinique and Barbados, from French Guiana and Guyana.An introduction to Jamaica was made in 1844 in an attempt to reduce the rat population.Despite its failure to control the rodents, the cane toad was introduced to Puerto Rico in the early 20th century in the hope that it would counter a beetle infestation that was ravaging the sugar cane plantations. The Puerto Rican scheme was successful and halted the economic damage caused by the beetles, prompting scientists in the 1930s to promote it as an ideal solution to agricultural pests.As a result, many countries in the Pacific region emulated the lead of Puerto Rico and introduced the toad in the 1930s. Since then, the cane toad has become a pest in many host countries, and poses a serious threat to native animals. They will feed on almost any terrestrial animal and compete with native amphibians for food and breeding habitats. Their toxic secretions are known to cause illness and death in domestic animals that come into contact with them, such as dogs and cats, and wildlife, such as snakes and lizards. When threatened, they are able to squirt the toxic secretion over a metre, causing extreme pain if rubbed into the eyes. Human fatalities have been recorded following ingestion of the eggs or adults.
  19. 24. Alien Name: Coptotermes Formosanus Common Name: Formosan subterranean termite Type: Insect Cause: Human Activity
  20. 25. Super-Termite The Formosan subterranean termite is an invasive species of termite. It has been transported worldwide from its native range in southern China to Formosa (Taiwan, where it gets its name) and Japan. In the 20th century it became established in South Africa, Hawaii and in the continental US. The Formosan subterranean termite is often nicknamed the super-termite because of its destructive habits. This is because of the large size of its colonies, and the termites' ability to consume wood at a rapid rate. A single colony may contain several million (compared with several hundred thousand termites for other subterranean termite species) that forage up to 100 m in soil. A mature colony can consume as much as 400g of wood a day and severely damage a structure in as little as three months. Because of its population size and foraging range, the presence of colonies poses serious threats to nearby structures. Once established, these termites has never been eradicated from an area. Their presence can easily go unnoticed for long periods of time. Infestations may not be noticed until floorboards become squishy or visible signs of the colony burrowing out through walls become apparent. Alien Name: Coptotermes Formosanus Common Name: Formosan subterranean termite Type: Insect Cause: Human Activity These termites are the most economically serious pest in Hawaii, costing residents $100 million a year. Their greatest impact is in North America. "C. formosanus Shiraki is currently one of the most destructive pests in the USA. It is estimated to cost consumers over US $1 billion annually for preventative and remedial treatment and to repair damage caused by this insect." In New Orleans, 30-50% of the city's 4,000 historic live Oak trees are believed to be infected with total damage costing the city $300 million a year.
  21. 26. Alien Name: Sturnus Vulgaris Common Name: Starling Type: Bird Cause: Human Introduction
  22. 27. Common Starling / European Starling It is among the most familiar of birds in temperate regions. This species of starling is native to most of temperate Europe and western Asia. It is resident in southern and western Europe and southwestern Asia. It has also been introduced to Australia, New Zealand, North America, and South Africa. Although there are approximately 200 million starlings in North America, they are all descendants of approximately 60 birds (or 100) released in 1890 in Central Park, New York, by Eugene Schieffelin, who was a member of the Acclimation Society of North America reputedly trying to introduce to North America every bird species mentioned in the works of William Shakespeare. European starlings (Sturnus vulgaris) cause damage to agricultural crops. When significant numbers are present starling flocks may descend on fruit and grain crop fields to forage, causing massive damage and can have a heavy economic effect. European starlings are extremely aggressive omnivores, and will compete with native fauna for food. Alien Name: Sturnus Vulgaris Common Name: Starling Type: Bird Cause: Human Introduction This adaptable species is considered to be a pest in several of the countries to which it has been introduced. The European Starling is a hole-nesting species and will nest in just about any cavity it finds. It has affected native species where it has been introduced because of competition for nest sites.
  23. 28. Want to know more about « Alien » species? Access a free course with videos, infos & test here: You can also dowload this presentation model to use it and customize it for your own needs (I know, it's really, really, really nice!)
  24. 29. This presentation is brought to you by Pierre-Etienne Chausse Do not hesitate to contact me regarding this presentation or tools used to do it [email_address]
  25. 30. Main Sources: Global Invasive Species Database A brief description and history of hundred of invasive species. Includes the TOP100 worst species!!! Invasive Species in Belgium Well made site with clear explanation and classification of invasive species in Belgium List of Invasive species on Wikipedia Especially useful for references and links to many more useful resources