Methods for identifying and tracking seaweed invasions

Tracking macroalgal invasions relies on a variety of approaches and techniques, including random sampling, active tracking near sources of introduction, and identification of alien species and their vectors of introduction using both classical means (based on taxonomical and biogeographical knowledge) and molecular tools. To identify the invaded ecosystems, and to describe the rate of spread and invasion dynamics, other approaches must be used, including mapping techniques and public awareness campaigns. In these endeavours, standardisation of geographical and density data is important. The tracking of alien species before eradication or control measures are instigated requires special cartographic techniques. This paper provides a general overview of these different approaches and the specific strategies adapted to the biological and ecological characteristics of particular species.