Key messages (CI6)

Key messages 

  • Progress has been made in creating national and regional inventories of alien species and assessing their pathways and impacts.
  • There is an increasing trend in the rate of new alien species introductions in the Mediterranean Sea.
  • Corridors are the most important pathways of new introductions in the Mediterranean, followed by shipping and aquaculture.
  • There is a need for better coordination at national and sub-regional level on NIS monitoring.

Knowledge gaps         

  • Evidence for most of the reported impacts of alien species is weak, mostly based on expert judgement; a need for stronger inference is needed based on experiments or ecological modelling. The assessment of trends in abundance and spatial distribution is largely lacking.
  • Regular dedicated monitoring and long time-series will be needed so that estimation of such trends is possible in the future. NIS identification is of crucial importance, and the lack of taxonomical expertise has already resulted in several NIS having been overlooked for certain time periods. The use of molecular approaches including bar-coding are often usefull besides traditional species identification.