Box 2: Case Study: Signal crayfish12

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1 Vision Populations of invasive species are monitored and managed where required. The distribution of invasive species is known and spread of the most damaging species is limited/ prevented. Invasive species do not have a negative impact upon ecosystem functioning Background Over the last millennia, humans have deliberately brought different species to Scotland from around the world, mainly for amenity or economic reasons. Farming, forestry and horticulture are just a few of the industries which have benefited from the presence of nonnative species. A number of species have also arrived accidentally, for example in the ballast water of ships or in consignments of goods imported into the UK. The majority of these species are a valued part of our natural heritage, contributing to our economic prosperity and enhancing the attractiveness of our gardens and diversity of our landscapes. Most non-native species are poorly adapted to survive in our environment and so never establish successfully in the wild. However, a small proportion of introduced species not only establish but thrive in Scottish ecosystems, assisted by a lack of predators or diseases which would otherwise keep their numbers in check. These can cause serious problems for our native species, to the environment and to our economy. Box 2: Case Study: Signal crayfish12 The North American Signal crayfish (Pacifastacus leniusculus) is a lobster-like invertebrate which can grow in excess of 16cm long and is found in freshwater habitats. They were introduced into Britain from North America, via Sweden, in the 1970s. Subsequent escapes from farms and deliberate illegal releases have resulted in the establishment of new feral Signal crayfish populations over large areas of England and Wales. Several records exist of Signal crayfish introductions to Scotland during the 1980s. They were first officially recorded in Scotland during In South Lanarkshire, Signal crayfish can be found in the River Clyde. Signal crayfish are highly adaptable organisms and can modify aquatic environments by eliminating aquatic vegetation and by burrowing into riverbanks or the shallow littoral areas of ponds and lochs. Signal crayfish have a significantly adverse impact on native

2 freshwater flora and fauna in running and standing waters. They can do this by consuming large quantities of plants and invertebrates, and by either predating or displacing amphibians and fish. Signal crayfish can also modify aquatic environments, by burrowing into the banks in rivers and ponds. In ponds, this behaviour can undermine the littoral zone and result in increased turbidity. In running waters, extensive burrows may destabilize the riparian zone, leading to increased rates of bank erosion, the shallowing of streams and the compaction of Salmonid and Lamprey spawning grounds. The species impact on Freshwater Pearl Mussel is unknown but is thought to be significant. The potential for Signal crayfish to act as a vector for transmission of diseases within or between catchments cannot be discounted. The Signal crayfish meets criterion 2 of the Species Action Framework, as an invasive non-native species which presents a significant risk to biodiversity. Its entry into Scotland is restricted by the Import of Live Fish (Scotland) Act 1978, Wildlife and Countryside Act 1981, as amended, Conservation of Native Freshwater Fish Stocks: The Prohibition of Keeping or Release of Live Fish (Specified Species) (Scotland) Order 2003 and the Nature Conservation (Scotland) Act Invasive species are a problem because they threaten native plants, animals and ecosystems, as well as impacting agricultural ecosystems and other human activity. Control costs and environmental damages can add up to millions of pounds every year. Invasive species can cause damage to ecosystems in a number of ways. Invasives are adept at out-competing native species, through a variety of different mechanisms. Invasive plants can form extensive monocultures that replace native plants needed by wildlife for food and habitat (e.g. Rhododendron ponticum; Himalayan balsam; Japanese knotweed). A number of invasive animal species predate upon native wildlife (e.g. American mink) and some spread disease which can also have a significant impact on native species (e.g. grey squirrel; signal crayfish). Several of the invasive plants are toxic, both to other plants and/ or animals and to humans (e.g. Rhododendron ponticum; giant hogweed). Invasive animals may also be more able to utilise the resources provided by the habitat than native species and so are able to increase their numbers rapidly (e.g. grey squirrel). Invasive species are often pests and can have significant and costly impacts upon agriculture, forestry and fisheries. Although it is desirable to eradicate invasive species, in many cases it is impossible. Control work can also be prohibitively expensive and so efforts should also be made to monitor the spread of and prevent the introduction and/ or establishment of invasives into new areas of habitat. Action to minimise the impact of invasive species in areas where they already occur is also necessary.

3 10.3 Themes This Biodiversity Strategy has identified three main areas of work in relation to invasive species, namely: control monitoring awareness The issue of monitoring the spread of invasive species and efforts to control them tend to be species specific and so each ecosystem plan has a suite of priority invasives identified. The actions associated with these species can be found in the appropriate ecosystem plan. For the purposes of this LBAP the following invasive species have been selected as priorities: Freshwater/ Wetland: Signal crayfish Himalayan balsam Giant hogweed Japanese knotweed American mink ny other species which are listed as priorities by SEPA; SNH A and Scottish Government Woodland: Rhododendron ponticum and hybrids Grey squirrel Any other species which are listed as priorities by SEPA; SNH and Scottish Government Upland Bracken (native) Any other species which are listed as priorities by SEPA; SNH and Scottish Government Lowland/ Urban New Zealand flatworm (gardens) Japanese knotweed Any other species which are listed as priorities by SEPA; SNH and Scottish Government

4 These species are predominately invasive non-natives but an invasive native (bracken) has also been included. The species which have been selected have been identified as priorities at a national level by SNH12, SEPA9 and SGRPID13 (shown in bold). A few local priorities have also been identified. This plan will be updated if national agencies identify new priorities Links to other LBAP Plans It should also be noted that whilst each of these priority invasive species has been assigned to an ecosystem group, many of them can and do cause problems across all ecosystems. Actions to monitor and control these species will therefore not be restricted to a single ecosystem, although actions may be prioritised in the highlighted ecosystem. Awareness raising and promoting good practice applies to all of the identified priority invasive species and so actions which are crosscutting in nature are outlined in this plan. Actions taken here will have strong links with those from the People and Communications Plan and the two plans should be used in conjunction with each other. The Climate Change Plan should also be referenced when using this plan as future climate change is likely to encourage new species to colonise areas which were previously unsuitable. This may lead to new priority invasive species being identified for action in the future. There is a slight risk that the drive to create habitat networks may facilitate the spread of invasive species. All actions taken in this LBAP will be evaluated so that this risk is minimised Key Plans, Programmes, Strategies and Legislation The Invasive Non-native Species Framework Strategy for Great Britain was launched in May Its overarching aim is to minimise the risk posed and reduce the negative impacts caused by invasive nonnative species in Great Britain. It is intended to provide a strategic framework within which the actions of government departments, their related bodies and key stakeholders can be better coordinated. A Scottish working group meets regularly to ensure effective policy co-ordination and practical implementation in Scotland. A number of national initiatives are currently taking place and the LBAP will feed into these as appropriate. At the time of writing, the Wildlife and Natural Environment Bill is due to be introduced to the Scottish Parliament at the end of This Bill (and subsequent Act) is likely to strengthen current legislation preventing the release of invasive species, create a Duty and provide additional powers to control invasive species and tighten the legislation relating to causing and permitting an offence.

5 Long Term Aim (LTA) 1: Invasive species are not threatening natural ecosystem functioning. Component 1: Monitoring (generic) Objective: Monitor and record extent, distribution and population numbers of priority invasive species. Justification: It is important to know the extent/ distribution and population size of priority invasive species. At present, this data is held by a range of organisations and is patchy in nature. A centralised database which collates the data held by SLBP organisations will enable a wide range of users to identify priority areas for monitoring and/ or control efforts. This database can also be made available to other decision makers to ensure the spread of invasive species is restricted. Measure(s): 1. Database is established. Data Collection Agency: 1. SLBP 2. Database is managed and updated regularly. 2. SLBP Target(s): 1. Database fully operational by Update regularly, no less than annually. Action(s): 1. Establish an invasive species sub-group of the SLBP. Responsible Body: 1. SLBP 2. Ensure full data exchange between partner organisations. 2. SLBP Partners 3. Establish database. 3. SLBP 4. Update database regularly. 4. SLBP Partners 5. SLBP to liaise with other organisations/ individuals to promote existence of database. 5. SLBP

6 Component 2: Awareness Objective: Raise awareness of invasive species and their associated negative impacts upon biodiversity and ecosystem functioning amongst local people/ developers/ contractors and land workers. Justification: Many people are unaware of the presence of invasive species and their associated negative impacts on native biodiversity. Awareness raising schemes will benefit the biodiversity of South Lanarkshire by encouraging local residents to be aware of invasive species and to report their occurrence. Local residents/ businesses/ contractors can also be encouraged to control invasives and can be made aware of behaviours which may facilitate their spread. Measure(s): 1. Information/ advice page on SLC website. Data Collection Agency: 1. SLC-CAG 2. Guidance documents/ leaflets available. 2. SLC-CAG Target(s): 1. Webpage functioning by Produce a guidance document pulling together invasive species information by Action(s): 1. Establish an invasive species sub-group of the SLBP. Responsible Body: 1. SLBP Partners 2. Produce guidance document. 2. SLC-CAG 3. Establish webpages. 3. SLBP Partners (e.g. SLC/ SEPA) 4. Maintain and update webpages regularly. 4. To be determined; SLBP Partners to feed in 5. Provide a consistent message when receiving enquiries. 5. SLBP Partners 6. Promote good practice and invasive species control to the general public and other key stakeholders. 6. SLBP Partners