aquaculture/mariculture. The two main shipping vectors together (i.e., Ballast water and
Hull fouling) constitute the primary pathway for almost one third of the NIS entering
the Mediterranean but as high as 45% of the NIS present in ADRIA.
Discussion
The current reflection served to deliver refined baselines for NIS in the Mediterranean
and its four subregions separately. The baselines include only validated species records
observed until the end of 2020 and are the result of much deliberation and collaboration
among a large number of national and taxonomic experts. As a result, both the alien
status but also the validity of records of a large number of species have been clarified
and agreed upon. Where knowledge was incomplete or consensus could not be reached,
species/records were flagged as Data Deficient but are still reported in the final
inventories for future reference. This was particularly the case for two major taxonomic
groups, the Polychaeta and the Foraminifera. In the first case, the status of a number of
species recently postulated as questionable aliens by Langeneck et al.. (2020) still
remains unresolved among taxonomic experts and it is recommended that specimens
collected throughout the Mediterranean are compared with type material before final
conclusions are reached. In the case of the Foraminifera, even though consensus was not
reached for many species, those that were agreed upon as valid NIS were included while
cryptogenic and Data Deficient were not considered in our analyses.
This is an important milestone for the implementation of IMAP and sets the foundation
for further steps, i.e., the elaboration of threshold values for new NIS introductions and
work towards numerically defining and assessing GES (Tsiamis et al.., 2019; 2021).
Thus far, assessment of GES for NIS temporal trends has been qualitative, based on
directional trends (e.g. UNEP/MAP, 2017). Even though threshold values for trends
indicators have not been elaborated yet (UNEP/MED, 2022; Vasilakopoulos et al..,
2022), refined baselines are a prerequisite for any potential approaches (e.g., Galanidi &
Zenetos, 2022; Tsiamis et al.., 2021). Furthermore, they constitute an important tool for
all other aspects of CI6, as a basis for species selection for the monitoring of species
distribution and abundance and the assessment of impacts. Nevertheless, only with
standardized and consistent monitoring schemes in place can CI6 become fully
operational.
Acknowledgments
This work was funded by UNEP/MAP-SPA/RAC under CONTRACT N°11_2021_SPA/RAC
IMAP-MAP PROJECT “Baseline of non-indigenous species in the Mediterranean”. We are
grateful to the national and taxonomic experts as well as the NIS Online Working Group for
their contributions and collaboration in refining the species inventories.
Bibliography
CBD (2010) - The Strategic Plan for Biodiversity 2011-2020 and the Aichi Biodiversity
Targets. Conference of the Parties to the Convention on Biological Diversity, Tenth meeting,
Nagoya, Japan, 18-29 October 2010.
CBD (2014) - UNEP/CBD/SBSTT A/18/9/Add.1. Pathways of introduction of invasive species,
their prioritization and management. Montreal, 26 June 2014
EU (2008) - Directive 2008/56/EC of the European Parliament and of the council of 17 June
2008 establishing a framework for community action in the field of marine environmental
policy (Marine Strategy Framework Directive). Off. J. Eur. Union 164, 19–40.
2nd Mediterranean Symposium on the Non-Indigenous Species (Genoa, Italy, 22-23 September 2022)
9
Hull fouling) constitute the primary pathway for almost one third of the NIS entering
the Mediterranean but as high as 45% of the NIS present in ADRIA.
Discussion
The current reflection served to deliver refined baselines for NIS in the Mediterranean
and its four subregions separately. The baselines include only validated species records
observed until the end of 2020 and are the result of much deliberation and collaboration
among a large number of national and taxonomic experts. As a result, both the alien
status but also the validity of records of a large number of species have been clarified
and agreed upon. Where knowledge was incomplete or consensus could not be reached,
species/records were flagged as Data Deficient but are still reported in the final
inventories for future reference. This was particularly the case for two major taxonomic
groups, the Polychaeta and the Foraminifera. In the first case, the status of a number of
species recently postulated as questionable aliens by Langeneck et al.. (2020) still
remains unresolved among taxonomic experts and it is recommended that specimens
collected throughout the Mediterranean are compared with type material before final
conclusions are reached. In the case of the Foraminifera, even though consensus was not
reached for many species, those that were agreed upon as valid NIS were included while
cryptogenic and Data Deficient were not considered in our analyses.
This is an important milestone for the implementation of IMAP and sets the foundation
for further steps, i.e., the elaboration of threshold values for new NIS introductions and
work towards numerically defining and assessing GES (Tsiamis et al.., 2019; 2021).
Thus far, assessment of GES for NIS temporal trends has been qualitative, based on
directional trends (e.g. UNEP/MAP, 2017). Even though threshold values for trends
indicators have not been elaborated yet (UNEP/MED, 2022; Vasilakopoulos et al..,
2022), refined baselines are a prerequisite for any potential approaches (e.g., Galanidi &
Zenetos, 2022; Tsiamis et al.., 2021). Furthermore, they constitute an important tool for
all other aspects of CI6, as a basis for species selection for the monitoring of species
distribution and abundance and the assessment of impacts. Nevertheless, only with
standardized and consistent monitoring schemes in place can CI6 become fully
operational.
Acknowledgments
This work was funded by UNEP/MAP-SPA/RAC under CONTRACT N°11_2021_SPA/RAC
IMAP-MAP PROJECT “Baseline of non-indigenous species in the Mediterranean”. We are
grateful to the national and taxonomic experts as well as the NIS Online Working Group for
their contributions and collaboration in refining the species inventories.
Bibliography
CBD (2010) - The Strategic Plan for Biodiversity 2011-2020 and the Aichi Biodiversity
Targets. Conference of the Parties to the Convention on Biological Diversity, Tenth meeting,
Nagoya, Japan, 18-29 October 2010.
CBD (2014) - UNEP/CBD/SBSTT A/18/9/Add.1. Pathways of introduction of invasive species,
their prioritization and management. Montreal, 26 June 2014
EU (2008) - Directive 2008/56/EC of the European Parliament and of the council of 17 June
2008 establishing a framework for community action in the field of marine environmental
policy (Marine Strategy Framework Directive). Off. J. Eur. Union 164, 19–40.
2nd Mediterranean Symposium on the Non-Indigenous Species (Genoa, Italy, 22-23 September 2022)
9