Table 8 Effects of sediment disposal on selected species, and consequences for the community. Abundance in the disposal area compared to the reference area: ↑ higher abundance, ↓ lower abundance, ♦ no response, –absent from data set

Dredge sample data

Mytilus edulis

Reduction, absent in disposal area; sensitive to sediment cover, turbidity

Loss of habitats and diversity (associated fauna)

Lanice conchilega

Reduction, partly absent in disposal area; sensitive to sediment cover

Loss of habitats and diversity (associated fauna)

Metridium senile

Significant reduction; sensitive to sediment cover

Reduction of diversity, loss of age structure

Sagartia troglodytes

Significant reduction; sensitive to sediment cover

Reduction of diversity, loss of age structure

Urticina eques

Reduction; sensitive to sediment cover

Reduction of diversity, loss of age structure

Sertularia cupressina

Reduction; sensitive to sediment cover

Reduction of diversity, endangered species

Balanus crenatus

Reduction, partly absent; sensitive to sediment cover

Indicates sensitive hard-bottom substrates

Asterias rubens

Significant reduction; associated with Mytilus

Indicates loss of prey (Mytilus)

Gammarus spp.

Associated with Mytilus and Obelia, therefore unspecified

–

Obelia longissima

Increase due to hard bottom substrates in the sediment discharge

Probably robust against short-term coverage with mud

Grab sample data

Nephtys caeca

Reduction, partly absent from the disposal area

Equilibrium species indicates stability and late succession stage

Petricola pholadiformis

Complete disappearance under sediment cover

Indicator of sediment deposits in special locations (peat, clay)

Bathyporeia pilosa

Reduction, partly absent from disposal area

Indicator of sandy habitats, avoids silt sediments

Eteone longa

Reduction, partly absent from disposal area

Abundance generally too low for indication

Macoma balthica

Robust species

Indicates nutrient increase; after a certain period opportunistic

Heteromastus filiformis

Increase of abundance, opportunistic

Indicator of silt and nutrient input, sediment change towards finer grain size