indigenous species”. The national implementation and harmonization of IMAP across
all Mediterranean countries requires the elaboration of a number of parameters, among
which the establishment of a refined baseline of the NIS present at the national and
regional level is fundamental as a starting point for any further evaluations. The current
work aimed to fulfill this target by bringing together the available information from a
variety of sources and employed a large pool of expertise in order to resolve
discrepancies in a collaborative and consultative manner.
Materials and methods
The national inventories of EU Mediterranean countries submitted to JRC (Joint
Research Centre of the European Commission) for the purposes of the 2012-2017
assessment cycle (Tsiamis et al.. 2021), were made available and formed the starting
point for the revision process of 8 EU countries. For the rest of the Mediterranean
countries, national NIS inventories were provided by designated national experts. For a
small number of countries that had not submitted national inventories initial national
baselines were created with data retrieved from the Hellenic Centre for Marine Research
(HCMR) offline database.
Besides NIS, cryptogenic and data deficient species were reported along with their year
of first detection, establishment success and most likely pathway(s) of introduction.
With regards to taxonomic groups, Foraminifera were treated inconsistently, with most
but not all countries including them in their inventories, and a strong divergence of
opinion among national experts on the status of many species.
The workflow of the elaboration process included 3 major steps: a) the critical revision
and update of the existing national inventories by SPA/RAC regional experts based on
recently published literature and major taxonomic/national/regional reviews, b) the
subsequent validation of the revised lists with the contribution of national experts,
invited/consulted taxonomic experts and the NIS Online Working Group, leading to the
refined and finalized inventories. The validation process included several rounds of
communication with countries’ experts whereby many discrepancies were resolved, and
a number of controversial species were agreed upon, c) the compilation of the regional
and subregional baselines, where national data were aggregated at two levels, the EcAp
subregion level and the pan-Mediterranean level. Once all national inventories were
completed, year of first detection and establishment success of each species were
adjusted accordingly.
Results
Results are reported based on data as collated until February 2022. In total, 1011 nonindigenous species were found in Mediterranean marine waters, of which 748 are
currently considered established (Tab.1), which makes the overall establishment rate
almost 74%. This value varies in the different subregions, with the lowest establishment
rate in CMED and the highest in EMED. When it comes to actual numbers, as expected,
the eastern Mediterranean has the highest number of NIS with 786 species, followed by
WMED, CMED and ADRIA.
Regarding unicellular phytoplankton species, following the review of the Tsiamis et al..
(2019) inventory by Gomez (2019), only a handful were included as NIS in the national
inventories, namely: Chaetoceros bacteriastroides G.H.H.Karsten, 1907, Chaetoceros
pseudosymmetricus Nielsen, 1931, Photobacterium damsela Love, Teebken-Fisher,
2nd Mediterranean Symposium on the Non-Indigenous Species (Genoa, Italy, 22-23 September 2022)
6
all Mediterranean countries requires the elaboration of a number of parameters, among
which the establishment of a refined baseline of the NIS present at the national and
regional level is fundamental as a starting point for any further evaluations. The current
work aimed to fulfill this target by bringing together the available information from a
variety of sources and employed a large pool of expertise in order to resolve
discrepancies in a collaborative and consultative manner.
Materials and methods
The national inventories of EU Mediterranean countries submitted to JRC (Joint
Research Centre of the European Commission) for the purposes of the 2012-2017
assessment cycle (Tsiamis et al.. 2021), were made available and formed the starting
point for the revision process of 8 EU countries. For the rest of the Mediterranean
countries, national NIS inventories were provided by designated national experts. For a
small number of countries that had not submitted national inventories initial national
baselines were created with data retrieved from the Hellenic Centre for Marine Research
(HCMR) offline database.
Besides NIS, cryptogenic and data deficient species were reported along with their year
of first detection, establishment success and most likely pathway(s) of introduction.
With regards to taxonomic groups, Foraminifera were treated inconsistently, with most
but not all countries including them in their inventories, and a strong divergence of
opinion among national experts on the status of many species.
The workflow of the elaboration process included 3 major steps: a) the critical revision
and update of the existing national inventories by SPA/RAC regional experts based on
recently published literature and major taxonomic/national/regional reviews, b) the
subsequent validation of the revised lists with the contribution of national experts,
invited/consulted taxonomic experts and the NIS Online Working Group, leading to the
refined and finalized inventories. The validation process included several rounds of
communication with countries’ experts whereby many discrepancies were resolved, and
a number of controversial species were agreed upon, c) the compilation of the regional
and subregional baselines, where national data were aggregated at two levels, the EcAp
subregion level and the pan-Mediterranean level. Once all national inventories were
completed, year of first detection and establishment success of each species were
adjusted accordingly.
Results
Results are reported based on data as collated until February 2022. In total, 1011 nonindigenous species were found in Mediterranean marine waters, of which 748 are
currently considered established (Tab.1), which makes the overall establishment rate
almost 74%. This value varies in the different subregions, with the lowest establishment
rate in CMED and the highest in EMED. When it comes to actual numbers, as expected,
the eastern Mediterranean has the highest number of NIS with 786 species, followed by
WMED, CMED and ADRIA.
Regarding unicellular phytoplankton species, following the review of the Tsiamis et al..
(2019) inventory by Gomez (2019), only a handful were included as NIS in the national
inventories, namely: Chaetoceros bacteriastroides G.H.H.Karsten, 1907, Chaetoceros
pseudosymmetricus Nielsen, 1931, Photobacterium damsela Love, Teebken-Fisher,
2nd Mediterranean Symposium on the Non-Indigenous Species (Genoa, Italy, 22-23 September 2022)
6