Pressures on natural resources - 3
Pest plants and animals
Following European occupation of Australia, plants and animals have been introduced – both intentionally and accidentally – in a steady flow. Most of these plants and animals do not pose serious threats, but some have become serious pests.
Some introduced plants are recognised as weeds of national significance (e.g. the blackberry, serrated tussock and willow) that threaten primary production and natural areas. Others are environmental weeds (e.g. cotoneasters).
Intentional introductions include plants given to householders and also planted liberally in city parks and gardens in the 1960s and 1970s. Others were introduced as pasture grasses into grazing areas that are now within the Canberra Nature Park and have consequently achieved weed status as land use has changed. Accidental introductions include seeds imported on machinery and in agricultural produce (e.g. hay for horses), or carried on wind in dust storms.
Pest plants and animals spread as the landscape is disturbed such as by urban development and opportunities for transport (e.g. on vehicles and machinery) are provided. Weeds more easily invade the ACT’s grassy ecosystems than areas that are forested. Even in moderately undisturbed areas, drought or grazing can open up the grass canopy so that windblown weed seed can take root and spread. Grazing by native or introuced animals can increase a weed’s rate of spread.
Introduced pests threaten biodiversity. For example, the European wasp has caused localised decline in native insect and insectivorous/honeyeater bird popluations.
Challenge: Prevention of further introductions of potential and actual pest plants and animals, and reduction in existing weed and feral animal problems through:
- improved community education about pest plant and animal control
- identification of priority areas that coincide with conservation goals and maximise connectivity
- strategic planning that includes identification of priority weeds and areas to be protected, as well as methods of control and
- recognition that weed control is a regional issue and
requires a cross jurisdictional and integrated approach.
Animal pests of the ACT (Pest Plants and Animals Declaration 2005 (No 1))
Animals
Mammals: rabbit (Oryctolagus cuniculus), dingo/dog (Canis lupus), deer (Cervus spp. & Dama spp.), pig (Sus scrofa), goat (Capra hircus), ferret (Mustela putoris), European red fox (Vulpes vulpes)
Birds: red-whiskered bulbul (Pycnonotus jocosus)
Amphibians: slider turtles (Trachemys spp.)
Fish: pike characin (Acestrorhynchidae); giant tigerfish (Hydrocynus spp., H. goliath); bowfin (Amia calva); climbing perch (Anabas testudineus); banded or spotted sunfish, largemouth bass, bluegill (Centrarchidae); snooks (Centropomus); Nile perch/forktail lates/sea bass (Lates microlepis, L. niloticus); snake head (Channa spp.); redeye & red piranha (Colossoma spp., Serrasalmus spp., Pygocentrus spp.); giant & yellow belly cichlid (Boulengerochromis microlepis); tilapia (Oreochromis spp., Sarotherodon spp., all Tilapia spp. except T. buttikoferi); pink, slender, greenwoods, Mortimers, Cunean and green happy (Sargochromis spp.); Serranochromis spp., African pike-characin, tubenose poacher, fin eaters (Citharinidae – subfamily Ichthyborinae); weatherloach (Misgurnus anguillicaudatus); carp (Aristichthys nobilis, Ctenopharyngodon idella, Cyprinus carpio, Hypophthalmichthys molitrix); copper mahseer (Barbodes hexagonolepis); Catla (Catla catla); giant barb (Catlocarpio siamensis); mrigal (Cirrhinus cirrhosus); orange fin labeo, rohu (Labeo calabasu, L. rohita); freshwater minnow (Zacco platypus); river carp, Deccan, high backed, Jungha, Putitor, Thai Mahseer (Tor spp.); pygmy sunfish (Elassoma spp.); Trahiras (Erythrinus spp., Hoplerythrinus spp., Hoplias spp.); pikes (Esox spp., Hepsetus odoe); ninespine stickleback (Pungitius pungitius); gobies (Acanthogobius fl avimanus, Tridentiger trigonocephalus, Oxyeleotris marmorata); aba aba (Gymnarchus niloticus); electric eel (Electrophorus electricus); American, armoured or alligator gars (Atractosteus spp., Lepisosteus spp.); bottlenose, Cornish jack (Mormyrops anguilloides); pike minnow, pike killifish (Belonesox belizanus); Gambusia (Gambusia spp.); African lungfish (Protopterus annectens); Valencia toothcarp (Valencia hispanica); catfi sh (Anaspidoglanis macrostoma, Bagrus ubangensis, Chaca spp., Clarias spp., Oxydoras spp., Schilbe mystus, Silurus spp., Trichomycteridae family, Heteropneustes fossilis, Malapterurus spp.)
Invertebrates: red imported fire ant (Solenopsis invicta), European wasp (Vespula germanica), red swamp crayfish (Procambarus clarkii)
