Phytoplankton and macrofauna in the low salinity ponds of a productive solar saltworks: Spatial variability of community structure and its major abiotic determinants

This paper focuses on the structure of the phytoplankton and macrobenthic invertebrates
communities in a productive solar saltworks, as well as the major abiotic determinants of the
observed biotic patterns. The observed patterns in the structure of the biotic communities
attest that the ecosystem of the low salinity ponds of Kalloni Saltworks is similar to a
productive coastal lagoon. Major abiotic determinants include the salinity and confinement
gradients, as well as inorganic nutrients loads. The episodic enrichment of the water column
in the ponds with either new nutrients from the incoming seawater, or regenerated nutrients
released from the sediment, was shown to stimulate the growth to bloom levels of
phytoplankton species indicative of organic enrichment and coastal eutrophication. Algal
biomass and the accumulated detritus and organic matter on and within the sediment are
exploited by opportunistic herbivores and deposit feeders tolerant to organic enrichment.
Management measures are needed for the mitigation of the productiveness of the low salinity
ponds, e.g. lower water residence times, a shallower water column, facilitation of the
oxygenation of the sediment, sediment removal in winter and culture and harvesting of the
naturally occuring, edible Cerastoderma glaucum bivalves.