Sentinel Species - Ecological Biomarkers: Indicators of Ecotoxicological Effects - page 165

TABLE 7.2
Common Coastal Organisms from United Kingdom and Northern Europe Coasts Selected for
Study in ECOMAN Program

Phylum Species Habitat Feeding Strategy

Echinodermata Asterina gibbosa Rocky shores, rock pools Omnivorous scavenger of

microorganisms, seaweed and
invertebrates

Asterias rubens Rocky mid-shore to sublittoral Carnivore

Urochordata Ciona intestinalis Sporadic distribution around

the lower shoreline

Sessile suspension feeder

Annelida Nereis diversicolor Burrows in estuarine mud,

rocky, muddy sand

Omnivore

Arenicola marina Mid to lower shore sand Deposit feeder

Mollusca Patella vulgata Intertidal rocky shore Herbivorous grazer of

microorganisms and algae

Littorina littorea Rocky coasts, estuaries, mud

flats, mid shore to sublittoral

Grazer of microorganisms,
detritus and algae

Nucella lapillus Mid shore to shallow rocky

sublittoral

Carnivore

Mytilus edulis Below mid-tide level, rocky

shores and estuaries

Sessile filter feeder

Cerastoderma edule Middle to lower shore, sand

and muddy sand

Filter feeder

Scrobicularia plana High shore intertidal soft

sediment, burrows up to 20 cm
below the surface

Filter and deposit feeder

Arthropoda Neomysis integer Euryhaline inshore waters Omnivore

Carcinus maenas Rocky coasts to soft sediment,

estuaries

Omnivore

Source: Modified from Galloway, T.S. et al., Mar. Pollut. Bull ., 53, 186-194, 2006.

the spatial organization of the community or temporal successions therein. Such species
are therefore keystone species. The examples that follow illustrate some levels of actions
of these keystone species.

7.2.1.1 Roles in Food Webs

Some species have a particular importance in an ecosystem through their activities of pre-
dation or by the biomass that they themselves offer as prey.

• Among the approximately 3000 species of ishes present in coral reefs, which are
among the most biologically productive and diverse ecosystems in the world and
among the world's most fragile and endangered ecosystems, the humphead parrot-
ish Bolbometopon muricatum is the only predator of the coral whose action can be con-
sidered significant. Figure 7.2 shows its impact on the ecosystem: by its bioerosion,