Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.485604
Title: An appraisal of Sabellaria spinulosa reefs in relation to their management and conservation
Author: Hendrick, Vicki Joanne
ISNI:       0000 0001 3553 1889
Awarding Body: University of Newcastle upon Tyne
Current Institution: University of Newcastle upon Tyne
Date of Award: 2008
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Abstract:
This thesis brings together a series of observations and investigations on the epifaunal, tubebuilding polychaete, Sabel/aria spillulosa Leuckart 1849 and ofthe reef habitat that can develop from coalesced tubes of gregarious aggregations of the species. Such biogenic reefs are of interest because they provide productive and diverse habitats as recognised by several conservation regulations, most notably their listing under Annex I of the Habitats Directive. Hence the purpose of the present study was to elucidate the nature of such struct~res with a view to informing decisions regarding their management and conservation. Key aspects of this thesis include a comprehensive review of the associated literature~ and an assessment of a wide range of datasets, collated from other investigators as well as collected ('. during this study, which confirms the ubiquitous UK distribution of the species. The assessment suggested that whilst the density of S. spinulosa is typically very low « 10 individuals/O.lm2 ), high density aggregations (> 200 individuals/0.lm2 ) represent a significant percentage (>50%) of the total population but these are sparse and cover a very small percentage «1%) of the area sampled, supporting their conservation interest. Size-frequency analysis of individuals collected from study sites in the outer Wash indicated considerable variation in recruitment success between years and a rapid turnover of individuals within the population despite the relative persistence of the colonies at the sampled locations. The time-series analysis also demonstrated the spatial and temporal variability of the colonies. Combined multivariate and structured equation modelling of the collated infaunal data indicated that dense colonies of S. spinulosa have a S!fucturing influence on the infaunal community, though it was not possible to identify any species that were typically associated with S. spinulosa reefs since the community structure also varied geographically. A series of observational and experimental studies of tube construction indicated that S spillulosa are capable of rapid tube growth (up to 6mmld-) under experimental conditions), and that they utilize a variety of particulate material to do so including quartz grains, shell fragments and coal particles. S. spinulosa were more selective about the size of particulate building matter than the source, typically favouring medium-sized particles (l20-500~m diameter) in preference to larger particles, which is likely to be a reflection of the worms handling capabilities. Cytoplasmic ribosomal RNA gene sequence alignment from five different S. spinulosa colonies identified only four base pair substitutions in the 5.8S rRNA gene and surrounding ITS regions amongst the 15 specimens assessed, indicating that the differences in tube morphology characteristic of i) encrusting and ii) reef-building colonies of S. spinulosa are probably determined by environmental rather than genetic factors. This analysis similarly suggests that the colonies are not genetically isolated from one another suggesting genetic mixing at the North Sea scale, or that genetic isolation if it has occurred was relatively recent. Finally, a multi-criteria scoring system was developed for evaluating 'reefiness' as a management tool to aid the implementation of legislative requirements that recognise the conservation importance of S. spinulosa reef habitats. Details of the physical assessment of six different S. spinulosa colonies undertaken as an industrial case study are presented as an example application of the approach. In summary, this research highlights the complex nature S. spinulosa at an individual and community level, its ecological importance, and some of the difficulties associated with S. spinulosa reefs and their management.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.485604  DOI: Not available
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