EPA ACTIVITY WORKSHEET TEACHER PAGE 1 6 Theme Class activity (CA). The students consider a second environmental problem of Irish interest the spread of the zebra mussel, a non-native species of shellfish, in Irish waters. Objectives Exploring real cases of environmental problems in Ireland to understand the range of issues and interests involved. Examining the complexity of a specific case. Curricular Strands SESE, Science and Geography Environmental awareness and care SESE, Science Living things; Plant and animal life SESE, Geography Human environments; Natural environments SPHE Myself and the wider world; Developing citizenship Skills Questioning, observing, investigating, recording and discussing Time 20 minutes introduction; 40 minutes discussion and role play Links to Green Schools Considering local environmental problems Zebra mussels DISCUSSING ENVIRONMENTAL ISSUES WHAT YOU NEED D Attached zebra mussel story and press releases WHAT YOU DO 1 Read The Zebra Mussel Story with the class and discuss initial reactions or questions. 2 Divide the students into groups and hand out copies of the press file. 3 Pass out copies of the attached table. Assign roles from the reactions table to the groups and ask them to brainstorm the possible reactions of their roles to the introduction of the zebra mussel. 4 Ask each group to present their thoughts. This could take the form of a public meeting or a political debate on the radio or television.
EPA ACTIVITY WORKSHEET TEACHER PAGE 2 6 Go further 1 Imagine you are an angler who just discovered a zebra mussel for the first time in a small local lake. What do you think you should do? 2 Discuss with the class the issue of who is responsible for this problem. What could have been done to prevent it? What can we learn from this about other potential problems? In this case, it is difficult to say that anyone really did anything wrong: the problem arose due to the fact that in the modern world people and boats travel more widely than before and carry alien species with them. So are these problems inevitable?
EPA ACTIVITY WORKSHEET STUDENT PAGE 3 6 THE ZEBRA MUSSEL STORY The zebra mussel is a shellfish related to the common mussel. The common mussel has been in Ireland for a very long time and is often found along the coastline of Ireland. Unlike the common mussel, the zebra mussel lives in freshwater (rivers and lakes) and is not eaten by humans. It gets its name from the stripy colours on its shell. It is not a native species: it first appeared in Ireland as recently as the 1990s. The zebra mussel originates from the Caspian and Black Sea basin in Europe. It can attach itself to the hulls of boats, and this is how it spread across Europe, travelling as a stowaway on the barges of Europe s canals and waterways. It reached England in 1824 and is believed to have reached Ireland on the hulls of second-hand boats from the UK sold in Ireland. It is believed to have been introduced to Ireland in areas of the lower Shannon River around 1994 and was first reported in Lough Derg in 1997. Zebra mussels begin their life as tiny larvae that are a bit like tadpoles. These larvae travel freely in water for about three weeks before they settle on a hard surface. It only takes three months for a zebra mussel to develop from its egg stage to a young mussel. Zebra mussels spread quickly because of their ability to produce huge numbers of young in a small amount of time and because the larvae can travel to new areas. The young mussels attach themselves to any available hard surface, including rocks, stones, piers, boats, pipes, plants and in some cases other mussel species. Zebra mussels have a number of effects on the rivers and lakes they colonise. The costs of cleaning the surfaces to which they are attached can be very high. Large numbers of mussels can build up on hard surfaces very quickly, and their weight has sunk buoys and moorings in the Shannon. As the mussels are not native to Ireland they have a huge impact on the native freshwater flora and fauna. In particular, research has shown that zebra mussels have a negative impact on some native freshwater mussels. Zebra mussels feed by filtering tiny plants and animals from the water. Large populations of zebra mussels develop once larvae have settled in a particular area, and these populations can have a dramatic effect on the availability of food in rivers and lakes in those areas. This in turn affects the other plants and animals living in the habitat. A number of government bodies in Ireland are involved in controlling the spread of the zebra mussel. Responsibility for controlling the spread of these mussels must be shared among all users of our rivers and lakes, including anglers, owners of boats and local authorities. Although the zebra mussel is likely to reach most freshwater rivers and lakes in Ireland, its rate of spread can be reduced through the cooperation of all involved. Some steps that can be taken include keeping boats in the water for the shortest time possible, cleaning boats regularly and ensuring they are cleaned before moving to a different river/lake or canal.
EPA ACTIVITY WORKSHEET STUDENT PAGE 4 6 PRESS FILE ZEBRA MUSSELS 1. Information from Western Regional Fisheries Board Web site (www.wrfb.ie) The Western Regional Fisheries Board has expressed grave concern about the possible introduction of the "Zebra Mussel" to the Corrib system. This exotic animal, which resembles the sea mussel except that it is small with zigzag stripes on the shell, has taken over the great lakes of America and other water bodies where it has been accidentally introduced. Following its discovery in the Shannon there are now major fears that it could find its way into the Corrib system and become established. Judging from the other limestone lakes that this animal has been introduced into, it could have a detrimental effect on the ecology of the lake. The animals can take over when suitable conditions are available. They are most likely to thrive when there is a hard substrate and suitable alkaline water supply. On the Lower Corrib conditions for the animal are ideal. In a very short time the animal can become established in vast numbers. Tens of thousands per square metre have been recorded in other waters. Many of the trout in Lough Corrib feed on plankton, particularly in the earlier periods of their life. The plankton as well as the freshwater shrimp are responsible for the pink colouration in the flesh of the Corrib trout. It is possible that this could become a thing of the past. In other lakes where the species has become well established there have been nuisance problems from vast numbers of the animal decaying on the lake shore after winter storms, causing a dreadful smell. We are calling on all water users to be extremely responsible and to heed a series of guidelines when contemplating bringing boats, engines, water, fishing tackle and all equipment from one catchment to another. DO NOT transfer boats from the Shannon System to any other water body, in particular to Loughs Corrib, Mask and Carra. PLEASE follow the recommended procedures when putting a boat on the water. In addition, fishermen bringing bait in water or dealers with live eels should under no circumstances fill with water in the Shannon and discharge into any other water body as the larvae are known to be transferred in this way. A special information leaflet is available to any interested person on request from the Western Regional Fisheries Board, Weir Lodge, Earl's Island, Galway. Tel: (091) 563118/9/0 Fax: (091) 566335 Email: info@wrfb.ie 2. Sligo Champion, 29 August 2001 Board worried at discovery of zebra mussels in lake The North Western Fisheries Board has launched a campaign to prevent the spread of zebra mussels on the Garavogue River and at Lough Gill. The Board this week expressed concern about the presence of zebra mussels, and a survey to examine the extent of the species is ongoing, but it is understood that once the mussels enter a river or lake, its population increases very rapidly. The discovery of a zebra mussel attached to a boat on the Garavogue River prompted the survey and further mussels were found there, with a very small number located in a part of Lough Gill. Notices informing anglers how to prevent the spread of zebra mussels have been posted at Lough Gill.
EPA ACTIVITY WORKSHEET STUDENT PAGE 5 6 3. The Leitrim Observer, 12 April 2000 Over 300 anglers staying away from Lough Melvin Over 300 anglers will not be coming to Lough Melvin this year due to the spread of zebra mussels in the lake, according to Chairman of Leitrim County Council, Cllr. Tony Ferguson. Speaking at the April meeting of the Council, Cllr. Ferguson asked the County Manager to provide funding towards the cost of a cleaning unit for boats on Lough Melvin to prevent the spread of zebra mussels which he said are a great problem to fish stocks. Cllr. Ferguson said that the other local authorities and fishing interests are giving funding towards this project and he asked that Leitrim County Council follow suit. Cllr. Ferguson said that the problem that exists is a great worry to local people and to the economy of the area. He said that over 300 anglers won t come to Lough Melvin this year as a result. His proposal was seconded by Cllr. Siobhán McGloin who said that it is a very serious issue and the Lough Melvin anglers are very concerned. She said that it has been decided to hold no competitions on Lough Melvin and to prevent outside boats from coming in, such is the concern. Cllr. Ferguson said that the situation is deteriorating quite rapidly and he asked the Council to look into it.
EPA ACTIVITY WORKSHEET STUDENT PAGE 6 6 REACTIONS ZEBRA MUSSEL PRESS FILE From your reading of the zebra mussel press file, how would you describe the reactions and opinions of the various people involved? Groups or individuals involved What they might think Anglers or local fisherman UK company selling boats in Ireland Tourist board promoting holidays travelling along Ireland s waterways Government marine scientist School pupil living beside the Shannon