Harmonia+: a quick-screening tool for potentially invasive species

The sooner invasive alien species become tackled during invasion, the more cost-effective measures against them will be. But before such prevention or early eradication measures can take place, it is essential to have first identified those species posing the highest risks. Given the huge and still-increasing number of species that become transported and may become problematic, such a prioritization must allow for a high number of species from different taxonomic groups to be assessed in a relatively short time. For Belgium, Branquart (2007) launched a scheme that allowed for a quick screening of species' capacity to spread and impacts on the environment (ISEIA protocol). Yet, during the years, this scheme was found to unsatisfactorily cover several issues, and the challenge was therefore to refine this scheme further yet retain its simplicity. We therefore constructed Harmonia+, which -compared to its predecessor- is more complete with regard to the invasion stages covered, with the different kinds of impacts included, and with the consideration of pathogens, among other improvements. More specifically, Harmonia+ presents about 30 key questions on a particular organism, the answers of which need to be provided by one or more assessors. These questions refer to the species' risks on (1) introduction, (2) establishment, (3) spread and (4) impacts, the latter of which are further subdivided into impacts on (4a) environmental, (4b) plant, (4c) animal and (4d) human health. The answers are ordinally scaled, and this allows to put the (separate and combined) risks into scores, which in turn, allows to rank species and prioritize actions against them. Harmonia+ has come about through the collaboration of eight Belgian scientific institutes, each providing their expertise on different components of the protocol. A first version was tested by an international panel of risk analysis experts, and later versions have been applied to test cases by national experts as a means of validation (see Branquart et al., this volume). Harmonia+ can be consulted at http://ias.biodiversity.be.