Chapter Ecological zonation and abiotic variability in an enclosed nature park: the case of the salini saltworks in malta

Abstract

The Salini saltern complex (SSC), was a natural wetland that now functions as a nature park. The SSC is oriented along a NE to SW axis measuring 740 m by 140 m, with a surface area of 90000 m2. It comprises two reservoirs at the seaward extremity (each 12000 m2 in area) and 33 smaller pans in the inland portion, with surface areas ranging from 900 m2 to 2000 m2. This study addressed a knowledge gap by recording abiotic and ecological conditions across the SSC and relating them to the external marine conditions. The salina was visited monthly between 25 July 2022 and 5 July 2023. During each visit, the temperature, pH, electrical conductivity, nitrate and phosphate concentration of water were measured in the open sea, in the two reservoirs, and in 15 pans. The diversity of macroalgae, spermatophytes, and non-planktonic fauna was evaluated through direct observation, collection of specimens and photographic monitoring. Water quality changed in spatial and temporal dimensions within the SSC. The principal trend was a sharp gradient of abiotic conditions along the primary axis of the SSC from the seaward side to the landward side, suggesting changes in the characteristics of water during its movement from the open sea into the reservoirs and the pans. The species richness increased from the open sea to the reservoirs and decreased to much lower levels in the pans. The elevated species richness in the reservoirs is attributable to the higher stability relative to the sea and pans.