During the assessment period (six years), the number of new non-native species introduced into the wild as a result of human activities, calculated from the beginning of the reference year (referred to in the initial assessment under Article 8 (1) of Directive 2008/56 / EC), has been reduced to a minimum and, if possible, to zero. . The indicator “New non-native species for the Baltic Sea” is used, which estimates the number of new non-native species for the Baltic Sea that have appeared in the Baltic Sea waters under Lithuanian jurisdiction during the observed period.

Abundance and spatial distribution of established non-native species, in particular invasive species, which contribute significantly to adverse effects on certain species groups or predominant habitat types. The condition is assessed according to the indicator “Species abundance and distribution in space”. According to the D2C2 criterion, the condition of the marine area was assessed according to 2 invasive species. The situation in terms of the prevalence of these species deteriorated compared to the first period. The disadvantage of applying the criterion is that there is no list of species at regional or sub-regional level for the assessment of the state of the marine environment.

Part of the group of species in which the adverse changes have occurred or the spatial extent of the predominant habitat type in which the adverse changes have occurred, if those adverse changes relate to non-native species, in particular invasive non-native species. The assessment of the marine area according to the D2C3 criterion was performed using the Biological Pollution Assessment Method (BPL index) for the two species included in the national list of invasive species: Dikerogammarus villosus and Neogobius melanostomus. However, the method has drawbacks that require additional targeted research. The BPL method was used in the initial assessment for the period 1990-2010. Evaluation according to the D2C3 criterion, applying the BPL method, showed that in 2012-2017. During the period, negative changes took place in the predominant type of habitats in the Lithuanian sea area. The level of biocontamination caused by the invasive species N. melanostomus increased from low (BPL = 1) to extreme (BPL = 4) from the initial assessment. In order to analyze the need for status assessment for the D2C3 criterion, other methods for assessing the impact of invasive species that were developed after 2007 were selected.