Risk Assessment of Alien Species

Conducting risk assessment is the important first step to effectively manage IAS because it provides an objective way to identify high-risk species requiring priority treatment (i.e. target IAS). The Department commissioned a consultancy study in 2018 to develop a risk assessment protocol appropriate to the local context, making reference to those being adopted in other regions. The protocol is applicable to all major taxonomic groups in both terrestrial and marine habitats.

Risk assessment protocol for alien species in Hong Kong          
The protocol is a questionnaire to be completed by an assessor with expertise in the taxonomic group concerned. It is divided into two sections. Section A covers background information of the species and a set of screening questions. Species screened for detailed assessments will be assessed in section B, for risks of entry, establishment, spread and impacts. A scoring system is employed to quantify the risks in these four areas. The four scores would add up to a final score which indicates the overall risk (i.e. invasiveness) of the species, categorising it to one of the three risk levels, namely, low-, moderate- and high-risk. The full risk assessment protocol can be found here.

Risk assessment of alien herpetofauna

Assessment of the risks of alien herpetofauna (which are relatively well-studied in Hong Kong) that have already entered Hong Kong and those that are likely to arrive in the future have been conducted using the protocol, as part of the consultancy study. The 16 species assessed were chosen making reference to past local occurrence records in the wild, international alien species databases and trade data. The assessment results are listed as follows:

	Species	Common name	Risk
Frogs	Eleutherodactylus coqui	Caribbean tree frog	Low
	E. planirostris	Greenhouse frog	Moderate
	Lithobates catesbeianus	American bull frog	Moderate
	Osteopilus septentrionalis	Cuban tree frog	Low
	Rhinella marina	Cane toad	Moderate
Turtles	Chelydra serpentina	Common snapping turtle	(Screened out)
	Cuora amboinensis	Southeast Asian box turtle	(Screened out)
	Mauremys sinensis	Chinese stripe-necked turtle	(Screened out)
	Trachemys scripta elegans	Red-eared slider	Moderate
Lizards	Anolis carolinensis	Green anole	Low
	A. sagrei	Brown anole	Low
	Calotes mystaceus	Indo-Chinese forest lizard	(Screened out)
	Hemidactylus brookii	Brook’s gecko	(Screened out)
	H. frenatus	House gecko	Low
	Physignathus cocincinus	Chinese water dragon	Low
	Podarcis sicula	Italian wall lizard	Low

Further reading:
Reports (no.1,2,3) of a consultancy study on a risk assessment protocol for alien species and their management.