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observed in this study. How crucial the timing of the disturbance would be to the
likelihood of patch formation ultimately would depend on the later stages of
successional dynamics on Drum Sands, this was not investigated in these experiments.
For example, if successional dynamics were slow and disturbed sediments did not
become dominated by trophic groups which repressed P. elegans colonisation, e.g.,
suspension feeders, P. elegans would be capable of numerically dominating some
time after the disturbance. This is a likely scenario on Drum Sands since the creation
of 'new' sediments in this study did not result in the presence of species which were
absent in the ambient community.
Capitella capitata was the only species to show an opportunistic response (c.f., Zajac
and Whitlatch, 1982a) to the disturbance created in this study, i.e., their numbers in
azoic samples were higher than those in ambient samples (Chapter 8) at that time.
During August and December, when P. elegans larval recruitment was low, C.
capitata was by far the most abundant species colonising the disturbed sediments, in
both patches and non-patches. Therefore, depending on time of disturbance, C.
capitata can dominate early stages of succession even within P. elegans patches. The
colonisation of disturbed sediments by P. elegans during August and December would
probably have been relatively slow. This has important implications for the effects of
small-scale disturbances within P. elegans patches. For example, numerical
dominance by C. capitata in the early stages of community establishment could lead
to different successional dynamics compared with that during April when larval P.
elegans recruitment dominated recruitment. This implies that for P. elegans patch
formation following a disturbance on Drum Sands, the timing of the disturbance is
critical.
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