Interim report of the HELCOM CORESET project

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5.5. Biopollution level index
1. Working team: Non-indigenous species
Authors: Maiju Lehtiniemi, Manfred Rolke, Malin Werner and Alexander Antsulevich
2. Name of the indicator
Biopollution level index
3. Unit of the indicator
An index based on the number, abundance, distribution
and impacts of non-indigenous species on native
communities, habitats and ecosystem functioning
4. Description of proposed indicator
Biological pollution (magnitude of bioinvasion impacts) is defi ned as the impact of non-indigenous
species (NIS) on ecological quality and includes (but is not confi ned to) the genetic alteration within
populations, the deterioration or modifi cation of habitats, the spreading of pathogens and parasites,
competition with and replacement of native species.
The BPL method (Olenin et al., 2007) takes into account the abundance and distribution range (ADR) of
NIS in relation to native biota and aggregates data on the magnitude of the impacts in three categories:
1) impacts on native communities, 2) habitats and, 3) ecosystem functioning. ADR varies within fi ve
classes, ranking a NIS from low abundance in a few localities (A) to occurrence in high numbers in all
localities (E). After ADR is established, three categories of impacts are considered, whose magnitude is
ranked on fi ve levels ranging from no impact (0) to massive impact (4) based on qualitative changes in
an invaded ecosystem. The theoretical justifi cation uses several well established ecological concepts, e.g.
“key species”, “type specifi c communities”, “habitat alteration, fragmentation and loss”, “functional
groups”, “food web shift”, etc. BPL aggregates the results of the assessment into fi ve categories: “No
bioinvasion impact”, “Weak”, “Moderate”, “Strong” and “Massive”.
5. Functional group or habitat type
All non-indigenous species
6. Policy relevance
Descriptor 2
(Descriptor 1 & 4: indirectly)
7. Use of the indicator in previous assessments
None
8. Link to anthropogenic pressures
Directly impacted by: Introductions of new species e.g. from shipping, intentional stocking to aquaculture
purposes or aquaria.
9. Pressure(s) that the indicator refl ect
Shipping activities (untreated ballast water, hull fouling)
10. Spatial considerations
The indicator should be estimated for specifi c areas (e.g. sub-basins
or assessment units consisting of national coastal and offshore waters) but can be generalized for larger
areas as well.
11. Temporal considerations
The indicator will be assessed every six years, but data collection is continuous.
12. Current monitoring
The monitoring of NISs is rare in the Baltic Sea as such. However, in other biological monitoring programs
(in the open sea and in coastal areas) e.g. in COMBINE program, NIS are often observed and counted,
which gives a certain level of data for the indicator. Nevertheless it would be important to increase monitoring
in specifi c less monitored habitats. The most problematic is to get information on the impacts of
NIS, which is not currently monitored. The data on impacts have to be searched from the literature.
13. Proposed or perceived target setting approach with a short justifi cation.
The goal is to minimize human mediated introductions of non-indigenous species. GES boundary for nonindigenous
species should be ‘no new introductions’. For the indicator in question the GES boundary should
be ‘No new non-indigenous species with known impacts’. This means that when an assessment is made
only the species, which have been introduced after the previous assessment will be taken into account.