Sediment and plant-associated macroinvertebrates were sampled in six shallow water bodies along the central part of the coast
of Mediterranean Spain. The size of ponds, salinity and hydroperiod were highly variable. Seventy-one taxa were recorded, some
of them were endemic or uncommon species, evidencing the important contribution of these ponds to biodiversity. Crustaceans
and gastropods of biogeographical interest were found in the most primeval site. Correspondence analysis showed that macroinvertebrate
assemblages responded to environmental variables such as salinity, temporality and eutrophication. The brackish
water fauna was dominated by crustaceans, while oligochaeta and insect larvae were abundant in freshwater conditions.
Oligochaetes were abundant at localities with high trophic level, whereas localities with semi-permanent waters were dominated
by chironomids. The density of macroinvertebrates was clearly related with trophic state but we did not find significant relationships
between density and salinity or water permanence. For plant associated samples our results showed negative relationships
between species richness and temporality or salinity, contrary to sediment samples, where the Oligochaeta/Chironomidae
ratio in sediments and the percentage of sensitive taxa (Ephemeroptera, Odonata, Trichoptera) were useful indices, and were
dependent on pond typology. This study emphasizes the broad ecological variety of ponds found in these wetlands and their
importance for biodiversity. Some ponds act as permanent biodiversity reservoirs in fluctuant marshes with seasonal dryness,
calling for more attention on their ecological relevance for management strategies.