A group of one or more organisms classified as a unit. The most commonly used and widely accepted taxonomic categories include kingdom, phylum, class, order, family, genus, species and subspecies. 

One member of a group; singular of taxa. 

Related to the classification and naming of species (taxonomy). 

A concept in international law meaning ‘a territory belonging to no-one’ or ‘over which no-one claims ownership’. The concept has been used to justify the invasion and colonisation of Australia.  

Likely to become endangered in the near future. 

A process or activity that ‘threatens … the survival, abundance or evolutionary development of a native species or ecological community’ (Environment Protection and Biodiversity Conservation Act 1999, p. 273) and which also may threaten the sustainability of resource use. 

A boundary between 2 relatively stable states; a point where a system can go rapidly into another state, usually because of positive feedback(s). 

(Indigenous); Indigenous people or nations who have responsibilities in caring for their Country. A Traditional Custodian may not have any ownership rights and/or those rights of custodianship may not necessarily apply to land but to things – tangible items – on the land. 

(Indigenous); an Indigenous owner of their traditional Country, as determined through the purchase of freehold, as granted by government or as determined through the native title process.  

Criteria levels within guidelines that trigger action; specifically, those that indicate a risk to the environment and a need to investigate or fix the cause. 

Related to an organism’s place in a food chain. Low trophic levels are at the base of the chain (e.g. microorganisms, plankton), high trophic levels are at the top of the chain (e.g. dingoes, sharks). 

A low-pressure system in which the core is warmer than its surroundings, with winds of at least 65 kilometres per hour around at least half of its circumference. Tropical cyclones are normally found over tropical and subtropical oceans and adjacent land areas, and occur mostly between November and April. 

The lowest layer of Earth’s atmosphere. Its depth varies with latitude, averaging around 17 kilometres in the mid-latitudes. 

A measure of water clarity or murkiness; an optical property that expresses the degree to which light is scattered and absorbed by molecules and particles in the water. Turbidity results from soluble coloured organic compounds and suspended particulate matter.