Listing Advice
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The Minister listed this as a key threatening process, effective from 26 February 2013 Advice to the Minister for Sustainability, Environment, Water, Population and Communities from the Threatened Species Scientific Committee (the Committee) on Amendments to the List of Key Threatening Processes under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) 1. NAME AND DESCRIPTION OF THE THREATENING PROCESS 1.1 Title of the process Novel biota and their impact on biodiversity The term ‘novel biota’ refers to organisms that are new to an ecosystem whether by natural or human introduction, the latter being the primary focus of this KTP. There are a large number of terms in common use that fall within the term but the use of ‘novel biota’ is intended as an all- encompassing term. 1.2 Name Changes The original title of the nomination was ‘The introduction of novel biota and its impact on biodiversity’. The Committee changed the name of the nomination to ‘Novel biota and their impact on biodiversity’ to reflect that the threatening process is not restricted to only the introduction of novel biota. 1.3 Description of the process Since the arrival of the first non-Indigenous people to Australia, introduced novel biota have posed an ongoing threat to Australia’s unique environment and biodiversity. Invasive species are considered by biologists to have the second most destructive impact on native species and ecological communities after habitat destruction (Sanderlund et al., 1999, p 2; Coutts-Smith and Downey, 2006). Recognising the environmental impact of introduced species, the Convention on Biological Diversity, of which Australia is a signatory, aims in Article 8 (h) to ‘Prevent the introduction of, control or eradicate those alien species which threaten ecosystems, habitats or species’ (Convention on Biological Diversity, 1993). This key threatening process (KTP) ‘Novel biota and their impact on biodiversity’, includes six major groups of novel biota that are impacting on biodiversity, as detailed below. Novel biota and their impact on biodiversity, including: A. Competition, predation or herbivory and habitat degradation by vertebrate pests. B. Competition, predation or herbivory and habitat degradation by invertebrate pests. C. Competition, habitat loss and degradation caused by terrestrial weeds. D. Competition, habitat loss and degradation caused by aquatic weeds and algae. E. Competition, predation or herbivory and habitat degradation by marine pests. F. Mortality, habitat loss and degradation caused by pathogens. This KTP does not include species in domestic, agricultural and commercial forestry situations where these species remain appropriately managed. These species would only be included in this KTP if they escape or are released from managed situations and become invasive, threatening biodiversity. This KTP does include further introductions of new genetic material of invasive species that are already present in Australia, such as buffel grass (Cenchrus ciliaris). Buffel grass is an important ‘Novel biota and their impact on biodiversity’ Listing Advice - Page 1 of 66 The Minister listed this as a key threatening process, effective from 26 February 2013 agricultural pasture species in northern Australia, however the species has escaped into the environment and is considered a major environmental weed in areas where it has established and displaces native species. Similarly, further introduction of leucaena (Leucaena leucocephala) a small shrub introduced for fodder and widely planted in tropical and sub tropical Australia, is covered by this KTP. Unless appropriately managed and heavily grazed it escapes into the surrounding environment and becomes an invasive weed, forming dense thickets that restrict and out-compete native species. The KTP also includes the introduction or further cultivation of potentially weedy species for the biofuel industry. Many species promoted as quality source biofuel plants have specific qualities such as hardiness, ability to outcompete other species, need for limited water and resistance to pests and disease, qualities that also make them excellent weed species (Low and Booth, 2007). Many of the best biofuel plants such as giant reed (Arundo donax) and spartina (Spartina sp.) are listed by the World Conservation Union in the top 100 of the World’s Worst Invaders (Lowe et al., 2000; Low and Booth, 2007). If these weedy species are widely planted in Australia it is expected that they will thrive as invasive weed species. Novel biota have an impact directly or indirectly on all of society. Economic losses and control costs to agriculture, fisheries and forestry enterprises are well documented (Pimentel, 2002; McLeod, 2004). In 2009, it was estimated that the loss from invasive vertebrate species alone was around $750 million (Gong et al., 2009) and Sinden et al., (2004) estimated the economic impact from weeds to be around $4 billion. Novel biota impact significantly on recreational values in the community, for example fire ants in Queensland potentially severely disrupt gardening and outdoor activities, and weeds prevent access to recreational areas. They also have social impacts such as effects on health and Indigenous people’s way of life. While these very important impacts are acknowledged, the purpose of the KTP is to assess the impact of invasive species on the environment and biodiversity. This overarching KTP includes novel biota which are currently not present in Australia but that may be introduced in the future, and species already in Australia that currently are not invasive but have the potential to become so. Any current or future novel biota that fit into the six broad categories outlined in the description above are considered to be included. A flowchart representing how species are included in the KTP is at Figure 1 below. The purpose of this KTP is to recognise the threat that all novel biota pose to the Australian environment and to highlight the vast array of different novel biota and the threats they pose. Novel biota, from introduced vertebrate species and deadly pathogens to smothering weeds both on land and in the sea, all have varying impacts on native ecosystems, but ultimately they all threaten the continued survival of the native species and ecological communities upon which they impact. ‘Novel biota and their impact on biodiversity’ Listing Advice - Page 2 of 66 The Minister listed this as a key threatening process, effective from 26 February 2013 Figure 1: Flow diagram Species entering via natural pathways Non-invasive Pre-border Species not currently Biosecurity present in Australia Invasive New threat abatement measures Specific single invasive taxa KTPs e.g. rabbits, foxes Existing threat abatement measures Novel biota and their Potentially invasive impact on Post-border ‘sleeper’ species in biodiversity KTP Biosecurity Australia Invasive species that are established in Australia that do not have a specific KTP 1.4 The use of the term novel biota Not all introduced species that fit into the six categories (A—F) included in this KTP pose a threat to the environment; many introduced species have become naturalised (survives naturally through reproduction) in Australia and it is only a small subset of these that become invasive (Williamson, 1996, p 2; Phillips et al., 2010 and references therein). Such species are recognised as novel to the habitat however this KTP includes introduced species that are not only novel but also significantly impacting on biodiversity. These species are referred to as invasive (species whose introduction and spread threatens ecosystems, habitats or species with economic or environmental harm) and are a threat to native biodiversity. For the purpose of this document, the term ‘novel biota’ refers to non-native or non-Indigenous invasive species that have been introduced and naturalised in a new habitat and have a significant detrimental impact on the environment. This KTP does not consider native species that, due to changing climate conditions or natural evolutionary change, extend their ranges into areas where they are not currently present. The extension of ranges may result in new combinations of native species that could result in changes to ecosystem functioning (Hobbs et al., 2006). This new combination of native species, while novel, is considered to be a natural change. This KTP includes native species translocated outside their range (except where translocation was ‘Novel biota and their impact on biodiversity’ Listing Advice - Page 3 of 66 The Minister listed this as a key threatening process, effective from 26 February 2013 for conservation purposes), that have become invasive and are adversely impacting on the environment. The Cootamundra wattle (Acacia baileyana) is an example of a native species that is now considered to be invasive after being translocated outside its range. The Cootamundra wattle is native to southern New South Wales but has been very widely planted as an ornamental. It is now naturalised in many parts of Australia and hybridises with other wattles (Morgan et al., 2002). The seeds of this small tree are spread by the spring-loaded action of its pods, and also by ants and birds. When it invades native bushland the Cootamundra wattle can replace local native shrubs and shade out native grasses and wildflowers. 1.5 Currently nationally listed KTPs There are currently 19 KTPs listed under the EPBC Act. Fourteen1 of these describe decline in native species and/or ecological communities caused by one or more invasive taxa including cats, foxes, feral pigs, gamba grass and fire ants (DEWHA, 2009a). This KTP encompasses the 14 currently listed specific invasive taxa KTPs, as well as other novel biota that are already established in Australia and species with the potential to become invasive in the future. There are a significant number of novel biota currently present in Australia, and of these only a very small proportion (14) are nationally listed as KTPs. Novel biota that are currently nationally listed as KTPs are considered to be some of the most detrimental species introduced into Australia and warranted being listed as a specific KTP.