Mapping serpulid worm reefs (Polychaeta: Serpulidae) for conservation management

Abstract

ABSTRACT1. This study describes investigations into mapping of the biogenic reefs produced by the polychaete worm, Serpula vermicularis, for the purposes of conservation management.2. Reef distribution throughout Loch Creran, Scotland, was mapped using a diver transect technique and was found to be restricted to a peripheral band, with a mean upper limit of distribution of 2.7 m. The mean lower limit was found to decrease with distance from the mouth of the loch, with a lower limit of 9.3 m in the lower basin rising to 6.6 m in the upper basin; the likely influence of a corresponding decrease in the upper depth distribution of muds is discussed.3. Through determination of the mean width of the reef band and coastline length, the areal extent of the reef band was estimated as 108 ha, revealing Loch Creran to harbour the most extensive known development of S. vermicularis reef habitat in the world.4. The utility of sidescan sonar in mapping serpulid reefs was examined in four of the major embayments. Reef material appeared as characteristic patterning on the sonargrams, with the morphology of individual larger reefs being discernible.5. Sidescan sonar was found to be particularly valuable for the identification and monitoring of threats to the conservation of serpulid reefs. Sidescan sonar surveying was found to facilitate identification of loss of habitat extent resulting from anthropogenic activities such as moorings, aquaculture installations and dredging and can also be used to monitor the potentially damaging activity of otter trawling. Further improvements in the mode of deployment of sidescan sonar are discussed.

Protecting the Commons: the use of Subtidal Ecosystem Engineers in Marine Management

“…In other European countries, SACs have been designated because of different autogenic reef‐forming ecosystem engineers: Sabellaria spinulosa and cold water coral mounds of Lophelia pertusa in the UK (De Santo, ) intertidal Sabellaria alveolata reefs in France (Desroy et al ., ), Serpula vermicularis tube worm reefs in Scotland (Moore et al ., ) and horse mussel Modiolus modiolus beds in the Irish sea (Lindenbaum et al ., ; Rees et al ., ; Sanderson et al ., ).…”

Bay-scale assessment of eelgrass beds using sidescan and video

“…Towfish data could be used to discern these impacts. Sidescan sonar imagery has been successful in discerning oyster and serpulid reefs and associated anthropogenic impacts in shallow waters (Moore et al 2009;van Overmeeren et al 2009;Raineault et al 2012).…”

Where’s the ‘reef’? A five year study of serpulid tube bioerosion in a Scottish sea loch

“…Anderson Smith (1887) described tubeworm aggregations in the loch in 1882, but the next published record comes from a diving survey in June 1989 (Connor 1990), and there is no published evidence confirming the presence of serpulid 'reefs' in Loch Creran between those dates. In November 1967, Gage (1972) towed an Agassiz trawl through South Shian Bay, an area which now supports some of the best-developed serpulid 'reefs' in Loch Creran (Moore et al 1998(Moore et al , 2009 (Moore et al 1998(Moore et al , 2009 …”

“…The most extensive examples are found in Loch Creran, a fjordic sea loch in Argyll, west Scotland, where aggregations of Serpula vermicularis L. occupy a narrow depth band (1 to 13 m) fringing the loch periphery and covering a total area of ~108 ha (see Fig. 2 in Moore et al 2009 for distribution as of July 2005). The S. vermicularis aggregations in Loch Creran are regarded as biogenic 'reefs' (Holt et al 1998), and ongoing scientific studies aim to promote effective conservation management of this rare bio tope (Moore et al 1998, Poloczanska et al 2004, Chapman et al 2007, Hughes et al 2008.…”

“…Mature worms extend their tubes at a mean rate of 33 mm yr -1 (Hughes et al 2008). Collapse and subsequent upward regrowth of clusters of tubes create 'ring-reefs' up to 2 m in diameter (Moore et al 2009), with total coverage in some areas exceeding 10% of the seabed (Moore et al 1998). The S. vermicularis aggregations originate on small stones or bivalve shells on a gently-sloping muddy sand substratum (Moore et al 1998).…”