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.
||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)
||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
|Synthetic compound contamination
||Waste: industrial effluent discharge
||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).
||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.).