The Application of Variable Chlorophyll Fluorescence to Microphytobenthic Biofilms
Abstract
Community assemblages of diatoms, green algae and
cyanobacteria comprise the microphytobenthos (MPB),
which inhabit benthic sediment ecosystems (Admiraal
1984; Underwood and Kromkamp 1999; Consalvey et al. 2004). Particular attention has been paid to the
analysis of intertidal soft sediment systems, e.g. cohesive
mudflat and sandy substrata typical of estuarine habitats.
Variable chlorophyll fluorescence has been applied to
these systems since the 1990s, in an attempt to investigate
the primary productivity and photophysiology of
the integrated biofilms, when viewed as a “black box
system”, and also at the species level (Sections 5, 6 and
7). These transient (i.e. temporary) biofilms are not confined
to such soft sediment habitats however, and more
recently application of fluorescence methodologies has
been applied to biofilms inhabiting rocky shores and
stromatolite systems (Kromkamp et al. 2007; Perkins
et al. 2007). However the large majority of published
work has centred upon benthic soft-sediment biofilms,
due to their important ecosystem functions of carbon
flow and sediment stability (Underwood and Kromkamp
1999). In the former their high magnitude of productivity
fuels carbon flow through invertebrate and bacterial food
webs to support important trophic levels of anthropogenically
exploited taxa, including coastal fish and shell
fisheries and coastal avifauna. In the case of sediment
stability, biogenic exopolymers, usually referred to as
extracellular polymeric substances (EPS), produced by
the MPB in part to facilitate mobility, may contribute
significantly to sediment stability, hence increasing the
sediment resistance to hydrodynamic stresses and thus
resistance to coastal erosion (e.g. Underwood and
Kromkamp 1999 and citations there-in). Finally, the
photosynthetic production of oxygen can be regarded as
an important ecosystem function.
Origin : Files produced by the author(s)
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