Mireille Consalvey PhD Thesis - University of St Andrews

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low tide to allow the cells sufficient time to migrate (Hay et al. 1993). Round and
Palmer (1966) first proposed a geotactic response and to date this remains a
highly plausible explanation.
4.4.6. Summary
1) There was a sequential increase in cells at the sediment surface of the
Tay Estuary over the low tide period and a subsequent decrease prior
to inundation
2) Cells from the Tay Estuary showed evidence of an endogenous
migratory rhythm
3) There was a sequential increase in cells at the sediment surface of the
Eden Estuary over the low tide period, but there was no decrease prior
to the time of inundation
4) Light was the main factor that controlled microphytobenthic
migration to the sediment surface of the Eden Estuary
5) Both darkening and submerging initiated a downwards migration of
microphytobenthos from the sediment surface of the Eden Estuary
From the literature it is clear that migration varies with location and
therefore more work needs to be conducted at more locations. Furthermore, the
controlled conditions in the laboratory situation are not representative of what the
cells will experience and the next chapter will examine the migratory behaviours
of microphytobenthic cells under ambient conditions.
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