Sensitivity to human activities

Activities listed are those which influence, or are likely to influence this habitat and which are assessed in the UK marine SAC project review. The sensitivity rank may require amendment in the light of new information becoming available.

Sensitivity to: Human activity Rank Comments
Siltation Extraction: sand/gravel (aggregate dredging)

Low

The likelihood of damage due to sediment plumes in areas adjacent to gravel extraction is unclear, as there is no knowledge of the effects of differing particle size upon Sabellaria. However, it would be surprising if damage was other than very localised given Sabellarias preference for turbid waters.
Changes in temperature Climate change/global warming

Low

Owing to the sublittoral habitat occupied by Sabellaria spinulosa it is not very sensitive to temperature change.
Synthetic compound contamination Waste: industrial effluent discharge

Low

Hoare & Hiscock (1974) investigated the distribution of marine organisms around the outfall from a bromide extraction plant in North Wales. The effluent has a pH of 4 and contained free halogens. Species richness and diversity was markedly reduced within 150 m of the outfall, but Sabellaria was found closer to the outfall than any other organism.
Changes in nutrient levels Waste: sewage discharge

Not sensitive*

Walker & Rees (1980) reported that in the discharge area and down tide of the area Sabellaria spinulosa was present in greater densities and diversities than elsewhere in the bay.
Abrasion Fishing: benthic trawling

High

Berhahn & Vorberg (1993) have suggested that Sabellaria spinulosa is a good indicator of fishing intensity in the Wadden Sea. Subtidal Sabellaria reefs are reported to have been lost due to physical damage in at least five areas. In the Wadden Sea, Reisen & Reise (1982) reported that extensive subtidal Sabellaria spinulosa reefs were lost from Lister Ley, island of Sylt, between 1924 and 1982. They attributed the losses to destruction by "heavy gear" as populations were in the way of shrimp trawling. Reise & Schubert (19870 reported similar losses from Norderau area, and attributed them to similar causes. Trawling still occurs in these areas and as a result Sabellaria has been replaced by Mytilus edulis and sand-dwelling amphipods in these areas (Reise & Schubert 1987). Populations have also been destroyed in Morecambe Bay (England) (Taylor 1993: Mistakidis 1956)
  Extraction: sand/gravel (aggregate dredging)

High

In the short term Sabellaria spinulosa reefs would be severely damaged by extensive aggregate dredging activities. The speed of recovery from such damage is currently unknown. Compared to fishing impacts, gravel extraction is likely to be more limited in extent, more controlled, and less likely to continue for very long periods of time. So although direct damage would obviously be severe, recovery from adjacent undamaged areas seems more likely.

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