D2C2 Established NIS (2.1, 2.1.1)

D2C3 Adverse effects of NIS (2.2, 2.2.1, 2.2.2)

D2C3 Adverse effects of NIS (2.2, 2.2.1, 2.2.2)

D2C3 Adverse effects of NIS (2.2, 2.2.1, 2.2.2)

LevelPressureEnvironment

ImpactPressureWaterColumn

ImpactPressureSeabedHabitats

ImpactPressureFunctionalGroup

NIS2_1

NISWaterColumnHabitat2_2

NISSeabedHabitats2_2

NISFunctionalGroups2_2

MarineCoast, MarineOceanic, MarineShelf

HabitatsOther

FishDemersal

Posidonia oceanica

No increase in proportion of NIS in the abundance or biomass of the respective community

all NIS spp include <5% of biomass or space coverage

all NIS spp include <5% of biomass or space coverage

NotAssessed

NotAssessed

NotAssessed

NotAssessed

Declining

Declining

Declining

Declining

Low

Low

Low

Low

Although there has been a considerable effort to identify invasive species and to compile the relevant data, there is little quantitative information regarding the abundance of these species in the environment as well as the rate of invasion. As a consequence there is a rather fuzzy and anecdotal picture regarding the trends in the establishment of these species and their actual (quantitative) overall impact on the goods and services provided by the marine ecosystem. This lack of information is essential since the Mediterranean is among European seas the one hosting the highest number of invasive species.

Although in the list of invasive species there are some phytoplankton ones known for their ability to cause algal blooms there are no records convincingly attributing such blooms to invasive species in Greece. Up to a point this is due to the prevailing oligotrophic conditions which do not favor extended blooms with the exception of very sheltered marine water bodies which receive significant nutrient inputs typically through reverine discharges. Since the main cause for the species introductions in the Mediterranean is the lack of sufficient control in Suez Canal (and to a lesser extend in Gibraltar) the issue is clearly transboundary.

The Caulerpa racemosa has also got established in Greek coastal waters, mainly in the Aegean, changing the vegetation pattern from seagrass to seaweed dominance (Katsanevakis et al. 2010). It has been found (among others) that covering the seabed with C. racemosa favours anoxic conditions and change in the behavior of various kinds of pollutants. Since the main cause for the species introductions in the Mediterranean is the lack of sufficient control in Suez Canal (and to a lesser extend in Gibraltar) the issue is clearly transboundary.

Some of the invasive species have been found to increase at the expense of other local species. For instance the Lagocephalus sceleratus in Cyprus is now a significant part of the fisheries catch and now this starts to be the case with the fishing in Greek waters (particularly the SE areas) outcompeting indigenous fish species for habitats and food resources or with other types of biological interactions (predation on larval stages etc). Other species such as Mnemiopsis leidyi which has caused catastrophic impacts on pelagic fish and fisheries in the Black Sea and is know present in the northern and central Aegean and the northern part of Levantine are known to dramatic reductions in zooplankton, ichthyoplankton, and zooplanktivorous fish populations.

Non related GES component

Non related GES component

Non related GES component

Non related GES component

Unknown_NotAssessed

Unknown_NotAssessed

The Mediterranean has the highest rate of colonization by invasive species. This is primarily related to the Lessepsian migration through the Suez Canal but also to other standard vectors of transport of NIS such as ballast water, and aquaculture.

The Mediterranean has the highest rate of colonization by invasive species. This is primarily related to the Lessepsian migration through the Suez Canal but also to other standard vectors of transport of NIS such as ballast water, and aquaculture.

The Mediterranean has the highest rate of colonization by invasive species. This is primarily related to the Lessepsian migration through the Suez Canal but also to other standard vectors of transport of NIS such as ballast water, and aquaculture.

The Mediterranean has the highest rate of colonization by invasive species. This is primarily related to the Lessepsian migration through the Suez Canal but also to other standard vectors of transport of NIS such as ballast water, and aquaculture.

• "Shipping & floating structures (all vessels
• Aquaculture
• UsesActivitiesOther

• "Shipping & floating structures (all vessels
• Aquaculture
• UsesActivitiesOther

• "Shipping & floating structures (all vessels
• Aquaculture
• UsesActivitiesOther

• "Shipping & floating structures (all vessels
• Aquaculture
• UsesActivitiesOther

There have not been any specific projects covering the area and including all major invasive species and their impacts, so there no data available on impacts with very few exceptions. To address this issue a major research program with adquate resources should be carried out and this could provide the information required after 4-6 years.

There have not been any specific projects covering the area and including all major invasive species and their impacts, so there no data available on impacts with very few exceptions. To address this issue a major research program with adquate resources should be carried out and this could provide the information required after 4-6 years.

There have not been any specific projects covering the area and including all major invasive species and their impacts, so there no data available on impacts with very few exceptions. To address this issue a major research program with adquate resources should be carried out and this could provide the information required after 4-6 years.

There have not been any specific projects covering the area and including all major invasive species and their impacts, so there no data available on impacts with very few exceptions. To address this issue a major research program with adquate resources should be carried out and this could provide the information required after 4-6 years.