Activity Card 12A

This lesson introduces students to Invasive alien species and some of the problems they can produce.

Lesson objectives To introduce the concept of Invasive species

To foster an understanding of the threats invasive species can pose to native plants and

animals as well as the ecosystem

Educate students in methods of bio security

1

2

Invasive non - native species (alien species) are species whose introduction or spread can threaten biological diversity or have other unforeseen impacts. Invasive species are a threat worldwide, second only direct habitat destruction. Their introduction is one of the major causes of extinction in freshwater ecosystems. Ireland has a unique set of plants and animals due to its geographic, abiotic, climatic and more recently human influences. Naturally these plants and animals would be in a state of environmental equilibrium. However, the equilibrium can be altered by the addition / removal of species. Alteration can be good or bad, though in time systems usually rebalance. The lesson can start by giving the concept of the ‘environment’ and how it can change both naturally and by human influence.

Encourage students to try to define ‘Invasive species’ and list both native and non native species that they are aware of.

How do new species get to Ireland? It would be useful to expand this question and ask students how plants and animals got to Ireland in the first place

Humans are effective at altering the environment around them, on purpose and by mistake. After the last ice age Ireland only had 11 native freshwater fish species, today 22 plus. Invasive non-native species pose a threat to Ireland’s unique biodiversity and threat to economic interests such as agriculture, forestry, fisheries and tourism.

Many animals have disappeared due to intentional removal. In Ireland the Wolf and Beaver were hunted to extinction whilst others have been intentionally introduced such as Roach and Chub. Species harmless in their original home have proved disastrous in new environments. The classic example of this is the rabbit to Australia.

3

Activity Card 12B

Rabbits originated in the Iberian Peninsula and were bought to the British Isles by the Romans / Normans. This was positive as they were a source of both food and clothing. In 1859 the rabbit was transported to Australia by Thomas Austin. He released 12 rabbits on ‘Barwon Park’ estate, Winchelsea, Victoria, because he missed hunting them. He famously said‘The introduction of a few rabbits could do little harm.’

The effect of rabbits on Australian ecology has been devastating. Rabbits are the most significant known factor in native species loss, as well as destroying farmland through burrowing and vegetation removal. The Australian government has spent tens of millions of dollars in control and eradication programmes with, minimal success.Unintentional introductions can occur when species are transported by humans. Three rat species (the Black, Norwegian and Polynesian) have spread as ‘hitchhikers’ on ships and have been blamed for the extinction of many species, including the ground nesting Dodo.Non-native plants are commonly introduced as ornamental plants or for erosion control, stock feed, or forestry. Whether they become invasive species is seldom clear in the beginning as many non-native ornamentals languish in the trade for years before suddenly becoming invasive.Ireland has a restricted list of invasive species by comparison with the UK. The notorious invasive species in Ireland are the aquatic plants. These push out native species and have the ability to alter the ecology of waterways. As a consequence waterways can be choked with a single species, leading to impeded navigation, restricted angling and impaired water based recreation. The following are some of the more high impact invasive plant species present in Ireland.

• Curly - leaved Waterweed (Lagarosiphon major) • Nuttall’s Pondweed (Elodea nuttallii) • New Zealand Pygmy weed (Crassula helmsii) • Red Water Fern (Azolla filiculoides) • Japanese Knotweed (Fallopia japonica) • Giant Hogweed (Heracleum mantegazzianum) • Himalayan Balsam (Impatiens glandulifera) • Giant Rhubarb (Gunnera tinctoria)

To control or remove invasives once they have taken hold takes time, money and effort. If left to their own devices the invasives can lead to the complete eradication of native species and alteration of habitats.

Activity Card 12C

Get students to look into at least one invasive alien species. Describe

• What the plant or animal looks like

• Explain where it came from

• How it got to Ireland

• The damage it can do

• How its spread can be controlled

Examples of Invasive species Japanese Knotweed (Fallopia japonica) is an invasive species listed by the World Conservation Unionas one of the world's 100 worst invasive species. Its root system and strong growth can damage foundations, buildings, flood defenses, roads, paving, retaining walls and architectural sites. Its success is attributed to tolerance of a wide range of soil types, pH and salinity. Its rhizomes can survive temperatures of −35 °C and extend up to 7 meters horizontally and 3 meters deep, making removal by excavation extremely difficult. The first confirmed sighting of Curly-leaved Waterweed (Lagarosiphon major) in Lough Corrib was at Rinnerroon Bay in April 2005. This plant is a tall, canopy-forming, submerged macrophyte, native to southern Africa. Since 2005 it has expanded throughout the northern and middle sections of the lough, colonising shallow sheltered bays. It forms dense infestations and is capable of occupying the full water column in waters to 5m deep. Its stems are easily broken floating freely. Lagarosiphon dramatically alters the ecology for native plants, insects and importantly fish, creating a poorer ecosystem. It can also cause fish kills through oxygen depletion. Infestations have made bays impossible to fish as well as making the environment more suitable for coarse rather than the game fish for which Lough Corrib is famous. It poses a serious threat to tourism, angling, boating and other recreational pursuits and the local economy.

The zebra mussel has been expanding its range for 200 years from the Black Sea and Aral – Caspian Sea basins. Its expansion through Europe has been facilitated by the development of canals linking major European river systems.Its invasion of the Great Lakes (in North America) resulted in major impacts including shutting down the water supply to Detroit and cooling water supply to a nuclear power station. Economic impacts between 1998 -2000 are estimated at $1 billion. Impacts include severe fouling of man-made structures, of fish spawning grounds, changes in fish populations, increases in water clarity and alteration of plankton communities in North America

Case study - Zebra mussel (Dreissena polymorpha)

Activity Card 12D

In Ireland its introduction is believed to have been unintentional. First noted in 1994, becoming invasive in the late 90’s. Its introduction is believed to have been via boating. Possibly attached to the hulls of second hand boats imported from Britain or the Netherlands. Boats, imported for private use on the Shannon Navigation system, could be lifted out of British waters, put on a trailer and transported to Ireland / Irish waters within a day. Zebra mussels were in the Lower Shannon River in ’94. By ‘96 they had spread (attached to leisure craft) to the entire navigation system of Loughs Derg, Ree and Key, as well as Lower Lough Erne via the recently restored Shannon-Erne Waterway in 1994. Background to the introduction Several events in ‘93 may have created an ‘invasion window’. In January ‘93 the abolition of VAT on second hand boats within the EU, Introduction of an English second hand boat certificate of competence. Exchange rate favouring exports from the UK to Ireland. Human activities enabled zebra mussel to expand by a combination of natural and human - dispersal mechanisms.

Problems caused by the introductionEconomic - water treatment plants, fish hatcheries and hydroelectric power stations in the Erne and Shannon systems have had to be modified to exclude zebra mussels. Education and public awareness campaigns have had to be financed.Ecological - there have been changes in the abiotic components of the ecosystem with alterations in some nutrient concentrations. A dramatic increase in water clarity. A decrease in plankton communities’ leading to food web alterations impacting on fish recruitment. Heavy infestations may interfere with the feeding, respiration and reproduction of freshwater mussels and impede locomotion. Zebra mussels can eliminate mussel populations.

How the introduction might have been preventedThe zebra mussel invasion occurred as a result of the removal of an economic barrier. As an accidental introduction it would have been difficult to prevent, but the key to prevention would be an awareness of practices that can spread invasive species, such as importing boats. To control zebra mussels, codes of practice for boat importers, tourists, sand abstractors, fisheries managers, anglers, boaters, marina / slipway managers, environmental agencies and researchers have been recommended. Initial steps include educating sectors, then deciding if sectors require specific codes of practice for their activities or if legislation is needed.Boats which are moved between different water systems should be carefully cleaned and any aquatic plant material attached removed.

12

3

Activity Card 12E

Get students to explain what Biosecurity is. For the animal / plant they have researched what effective bio security is / could / should be put in place?

Bio security Biosecurity is a set of preventive measures designed to reduce the risk of transmission of infectious diseases, quarantined pests or invasive alien species. The introduction of alien species represents major threats to Ireland’s habitats, native species and internationally renowned fisheries. The ecology of invaded watercourses can become dramatically altered and may become unsuitable for water-based amenity and recreational pursuits. IFI has established protocols for the disinfection of equipment, clothes and vehicles used for field survey operations conducted by its staff and now protocols are being compiled to advise the publicof appropriate disinfection procedures. All angling equipment, protective clothing and footwear, nets, boats and boat engines should be thoroughly cleaned and disinfected to ensure that no cross-contamination with invasive species or pathogens occurs.

At the end of this lesson, students should know• What Invasive species are and be able to name 5

• Some of the ways Invasive species get to Ireland

• What threats they pose to the natural ecosystem

• What is meant by bio security

• What can be done to try to reduce / control their spread, understand and promote

bio security

Internet links and resourceswww.caisie.iewww.invasivespeciesireland.comwww.habitas.org.uk/invasive/www.doeni.gov.uk/niea/invasivespeciesinirelandquercusreport.pdfwww.fisheriesireland.ie/

Who are CAISIE? CAISIE stands for The Control of Aquatic Invasive Species and Restoration of Natural Communities in Ireland. As every day passes by Invasive alien species are running, swimming or lingering around under our noses, going undetected, blending into the background and slowly creating chaos for our native species. This 4 year EU funded project commenced in September 2009. The broad objective of the project is to contribute to the halting of biodiversity loss in Ireland by preventing further impacts on native biodiversity from high impact aquatic invasive species. The team will develop and demonstrate effective control methods and raise levels of awareness throughout the country.

Activity Card 12F

Glossary of terms Invasive - tending to intrude or encroach. Species - a class of individuals or objects grouped by virtue of their common attributesand assigned a common name. Invasive species - species whose introduction or spread can threaten biological diversityor have other unforeseen impacts. Ecosystem - complex of living organisms, their physical environment and interrelationshipsin a particular area. Bio security - is a set of preventive measures designed to reduce the risk of transmissionof infectious diseases, quarantined pests, invasive alien species, living modified organisms.