Spatial and seasonal variability of the macrobenthic fauna in Mediterranean solar saltworks ecosystems

Abstract

ABSTRACT1. Solar saltworks are man-made systems for the production of salt and are characterized by high habitat heterogeneity owing to the existence of a strong salinity/confinement gradient. Although solar saltworks are considered to be artificial systems, they are also coastal aquatic ecosystems sharing common characteristics with natural transitional waters ecosystems, which are of special interest to the Water Framework Directive (2000/60/ EC).2. Spatial and seasonal distribution of macrobenthic invertebrates in relation to the abiotic environment of two Mediterranean solar saltworks ecosystems were assessed in this study. The spatial distribution investigated in this study ranged from the regional scale (Kalloni Saltworks, NE Aegean and Margherita di Savoia Saltworks, S. Adriatic) down to a local scale of 100s of metres in each ecosystem.3. The macrobenthic community was variable at most spatial and seasonal scales examined in this study: spatial variability at the regional level was greater than seasonal variability within ecosystems and spatial variability among the salinity/confinement gradient levels was greater than within-level variability.4. The abiotic environment, in both its spatial and seasonal aspects, was found to be crucial in determining the macrobenthic community structure. Biotic factors such as the life cycle of key species, the inter-specific competition as well as dispersion/colonization/extinction processes were also found to play an important role in structuring the macrobenthic fauna both in space and time.5. A strong similarity of the macroinvertebrate faunal composition and community structure of the lower salinity ponds of solar saltworks with that of natural transitional waters ecosystems was observed. Therefore, solar saltworks ecosystems can be considered as important sites of study for the purposes of the Water Framework Directive.

First record of the protected species Pinna nobilis (Linnaeus, 1758) in the Aquatina Lagoon (NATURA 2000 site IT9150003, South-East Italian coastline)

“…Since P. nobilis is actually exposed to many abiotic and biotic sources of perturbations that are dramatically depleting the populations in the Mediterranean Sea (Vázquez-Luis et al 2017), this new record becomes significantly relevant in confirming the presence of a new population in the Adriatic Sea. Actually, the ecological assessment of lagoons, traditionally done by the sampling of the benthic macroinvertebrate communities (Evagelopoulos et al 2008;Pinna et al 2013), requires the application of time-consuming and high cost procedures; on the contrary, the monitoring of P. nobilis, the largest body-size benthic macroinvertebrate species of the Mediterranean Sea, is faster and cheaper and could suggest the developing of new and smart ecological indicators for rapid assessment of Mediterranean lagoons, as well as for innovative eco-genomic tools (Pawlowski et al 2018). The results of our research show the relevance of the NATURA 2000 network as an effective tool for biodiversity conservation at EU scale and, moreover, underline the importance of Mediterranean transitional water ecosystems as "nursery habitat" for P. nobilis as well as their potential use for promoting breeding programmes in the Aquatina Lagoon and future restocking of resistant juvenile individuals.…”

Selection of ecological indicators for the conservation, management and monitoring of Mediterranean coastal salinas

“…The flow of water through these ponds creates a steep and stable gradient of physicochemical characteristics, mainly salinity (Baudin 1980;Britton and Johnson 1987;Javor 1989). The spatial organization of the ponds in the salinas and of their different depths, necessary for the salt production process, favors a high degree of spatial heterogeneity and very productive microenvironments that are attractive to many primary and secondary consumers (Evagelopoulos et al 2008;Hamdi et al 2008). Such conditions are tolerated by aquatic communities with complex cycles and interspecific relationships and by species which are highly specialized for life in this environment (Geddes et al 1981;Williams 1993;Forbes and Cyrus 1993;Marín and d'Ayala 1996).…”

Diversity partitioning of a phytoplankton community in semiarid salterns

“…The management of brine flow through the evaporators provides a steep and stable gradient of physical and chemical characteristics, mainly salinity (Britton and Johnson 1987;Javor 1989). The spatial arrangement of evaporators in the salt marshes and their different depths are necessary for the salt-production process, which favours high spatial heterogeneity and productive microenvironments (Evagelopoulos et al 2008;Hamdi et al 2008). These I II III I II III I II III Chlorophyceae conditions developed by the saline environment are tolerated by aquatic communities through complex life cycles and interspecific relationships of species that can adapt and develop in these harsh environments (Geddes et al 1981;Forbes and Cyrus 1993;Williams 1993;López et al 2010).…”