Baseline Environmental Survey of the Sukkursu Canal, Salini: The Largest Transitional Water Body in Malta.

Scerri, R.-M.; Borg, J.A.; Evans, J., and Schembri, P.J., 2025. Baseline environmental survey of the Sukkursu Canal, Salini: The largest transitional water body in Malta. Although large transitional water bodies on continental Europe, such as estuaries and lagoons, have been well studied and characterised, those present on islands have received less attention. As a small island-state with a semiarid climate, Malta possesses limited areas with transitional waters. The largest such area is a U-shaped canal known as the Sukkursu, which owes its existence to historic coastal modifications dating back to the time of the Knights of St John (16th century). The present study aimed to establish the environmental characteristics of the Sukkursu canal, especially with regard to the macrofauna and macroalgae associated with its submerged water–land interface, and the physical and chemical characteristics of this transitional water body, which is a protected area. Collection of physical, chemical, and biotic data was carried out in all four seasons over a 1-year period from stations established around the canal. Assessment of physical and chemical data included measurements of water current speed and direction, temperature, salinity, turbidity, dissolved oxygen, nutrients (reactive nitrate, phosphates, and ammonia), and chlorophyll-a. Quadrat, core, and hand-net samples were taken to collect biota, which was identified and counted. The results indicated that the water current in the canal predominantly flowed inwards along its wide western arm but was bidirectional to a great extent along the narrower eastern arm, resulting in reduced water flow and eutrophication. Overall, physical and chemical parameters varied significantly at both temporally and spatially. The outer stations differed from the inner ones in having higher macrofaunal abundance, number of macrofaunal species, total number of algal species, and biotic diversity, irrespective of season. Overall, the results obtained infer a strong influence of water movement at the outer stations, which permits replenishment by coastal seawater that has good water quality characteristics, but such influence is weaker at the inner stations. [ABSTRACT FROM AUTHOR]