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 Coastal defence: seawalls/breakwaters


Sabellaria alveolata is sensitive to changes in sediment regime. In the Mediterranean Gulf of Valencia, Spain S. alveolata populations were lost as a result of sand level rise brought about as a consequence of the construction of seawalls and marinas/harbours, and beach nourishment projects. Long term burial by sand has been shown to kill S. alveolata reefs (Perkins 1967). On more open coasts, shore defences on one stretch of coast may lead to a reduced sand supply to neighbouring areas and therefore reduced development of S. alveolata reefs.
Changes in temperature Waste: cooling water (power stations) Not sensitive* Studies at Hinkley Point, Somerset, found that growth of the tubes in the winter was considerably greater in the cooling water outfall where the water temperature was raised by around 8-10oC, than at a control site, although the size of the individual worms themselves seemed to be unaffected (Bamber & Irving 1997).
Synthetic compound contamination Waste: industrial effluent discharge Low There is little evidence to suggest sensitivity to chemical contaminants, though this has been suggested as one of the possible causes of loss of S. alveolata in the Dee estuary (Craggs 1982).
Abrasion Recreation: popular beach/resort


Cunningham et al. (1984) showed rapid recovery from single trampling events of a light or moderate nature. More extensive damage to colonies (i.e. chunks being removed) was less evident in the short term, but some such damage did occur and was subsequently enlarged by wave action.

Sabellaria alveolata reefs in the vicinity of intensive mussel aquaculture are vulnerable to damage from trampling by commercial collection of the mussels.

Removal of target species Collecting: bait digging


Damage to colonies by people opening tubes with knives and removing the worms for use as fishing bait has been observed, though nowhere has this been seen on any intensive scale (Hawkins pers. obs.).

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