When time is a key ally
The successful management of invasive alien species (IAS) strongly depends on a key ally: time. When introduced to a new location, species must first survive, establish viable populations and finally spread in the environment under the current environmental conditions. Throughout the invasion process, the population growth of many IAS follows a specific trajectory which includes a lag phase before a period of exponential growth. This observed lag, is a critical time for efforts to manage IAS.
Indeed, the probability to remove a species decreases while related costs increase as an IAS spreads over time. The complete and successful removal of an invasive species is therefore only feasible if it is detected soon enough after its introduction in the ecosystem. However, if the invader is not detected and removed rapidly, eradication becomes increasingly less likely or even impossible. In that case, the available solutions are reduced to long-term and costly management actions, where appropriate.
Early detection and rapid response (EDRR) has, therefore, frequently been mentioned, notably at the Sixth Conference of the Parties to the Convention on Biological Diversity (CBD) in 2002, as an essential principle to mitigate the problem of biological invasions. However, the ability to react immediately to new invaders is often still insufficient. New arrivals are also often detected too late, when efforts to control are no longer practical. Enhancing countries’ ability to detect and record these species is therefore crucial so that reliable, timely and effective decisions and management actions can be implemented before species establish and spread.