BMA are recognised as important primary producers
in shallow aquatic ecosystems, their biomass and production can
equal or exceed that of phytoplankton in these systems. Furthermore,
the taxonomy and ecology of BMA are distinct from those of the phytoplankton.
The community consists primarily of diatoms, dinoflagellates and
some filamentous cyanobacteria, inhabitating the top few centimetres
of the substrate. BMA have an important role as a substantial source
of benthic primary production. BMA alter the flux of nutrients across
the sediment-water interface, the chemical gradients within the
sediment and sediment denitrification and affect sediment stability
through exopolymer production, a secondary product of photosynthesis.
Despite their potential importance BMA remains a neglected field
of study in sub-tropical and tropical ecosystems with much of the
work so far concentrating on northern hemisphere estuarine systems.
In Australia the benthic microalgal community has been largely ignored
in shallow coastal systems, limited to Port Phillip Bay, Peel Harvey
Estuary, Moreton Bay and Heron Island. Preliminary work on BMA in
Moreton Bay suggests it may be the most productive plant within
the Bay area. It is extremely important that we begin to understand
the production and nutrient dynamics of BMA as their ecological
importance is likely to increase in the future compared to other
coastal primary producers due to coastal habitat degradation such
as mangrove and seagrass destruction.
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