Differences between zooplankton structure (species abundance and size distribution)
and dynamics of permanent and temporary basins of a Mediterranean salt
marsh (Empordà Wetlands, NE Spain) were analysed by means of taxon-based and
size-based approaches. These basins are shallow bodies of water which are occasionally
connected. They were isolated after water retreat from a broadly flooded, lowlying
area close to the open sea. Although temporary and permanent basins show no
differences in the most abundant zooplankton species, they differ in their zooplankton
diversity, temporal pattern and size structure. The zooplankton assemblages of temporary
basins exhibit a temporal pattern with six phases, which are conditioned to the
hydrological cycle, each one dominated by one species, whereas in the permanent
basin this temporal pattern shows only two phases. Zooplankton size distribution of
the temporary basins is dominated by large sizes (copepodites and copepods) while the
permanent basin is dominated mainly by small sizes (rotifera and nauplii of copepods).
In the temporary basins, the shape of the biomass size spectrum changes according to
the hydrological cycle and reflects the dynamics of the ecological interactions among
zooplankton species