Survivorship and tube growth in reef-building Serpula vermicularis (Polychaeta: Serpulidae) in two Scottish sea lochs. Aquatic Conservation: Marine and Freshwater Ecosystems

1. In the UK, reef formation by the tubicolous polychaete Serpula vermicularis L. has been recorded in only two sea lochs in Argyll, west Scotland. Serpula vermicularis aggregations are now confined to Loch Creran, those in Loch Sween having died out for unknown reasons. 2. Survivorship and tube extension rates were measured in situ in order to compare habitat quality of the two sea lochs and to determine the feasibility of artificial restoration of Loch Sween reefs using stock translocated from Loch Creran. After labelling and measurement, clusters of inhabited tubes collected from Loch Creran were re-planted at two sites in Loch Sween and two in Loch Creran in July 2004, and monitored at intervals before recovery and remeasurement in July 2005. 3. In Loch Sween the tube clusters gradually disappeared over the monitoring period. Only remnants were left by May 2005 and no growth data were obtained. In Loch Creran 76% of the labelled tubes were relocated. Confirmed mortality over the year was 5.3% and mean tube extension rate was 33 mm y(-1). 4. There was no significant difference in tube growth between the two Loch Creran sites and inter-individual differences accounted for most of the variability in the data. Individual tube extension declined significantly with worm body mass but mean extension showed no relationship to total worm biomass in each cluster. Annual tube extension rate in Loch Creran was low in comparison with literature data from other serpulids, suggesting that tube growth is strongly seasonal. 5. The 10-month persistence of some living worms in Loch Sween suggests that there is no physiological barrier to survival of stock translocated from Loch Creran but in situ video monitoring would be necessary to determine the cause of tube disappearance. Copyright (c) 2007 John Wiley & Sons, Ltd.