Depositional environments, sediment characteristics, palaeoecological analysis and environmental assessment of an internationally protected shallow Mediterranean lagoon, Gialova Lagoon – Navarino Bay, Greece

Abstract

This study presents sedimentological, palaeoecological and geochemical data from a shallow Mediterranean coastal lagoon which has been severely influenced by human intervention over the last 70 years. The Gialova Lagoon is protected by international conventions and is listed in the Natura 2000 European Community Network as Special Protection Area (SPA) and Site of Community Importance (SCI). The spatial variability of sediment characteristics such as grain size, total organic carbon (TOC) and moment measures, mean, sorting, kurtosis and skewness were calculated. Moreover, micro- and macrofossil and sediment geochemical analyses were carried out on six gravity core samples. Study of the above parameters indicates that the anthropogenic impact and intervention are reflected in the micro- (ostracods, foraminifera, charophytes) and macrofossil (molluscs) taxa corresponding to different depositional environmental facies, representing a brackish lagoon with the influence of (a) fresh water inflow, (b) shallow marine environment and (c) hypoxic and dystrophic conditions. The geochemical characteristics and the calculation of the degree of sediment contamination using enrichment factors (EF), contamination factors (Cif) and the index of geo-accumulation (Igeo) indicate a recent relative improvement of the lagoon towards the upper layers of the gravity cores, rendering the lagoon as unpolluted to moderately polluted. This combinatorial study of sediment geochemical characteristics, as well as the downcore micro- and macrofossil assemblages, can be considered as a baseline for future monitoring in accordance with European Union directives, and for any future engineering interventions for the lagoon environmental maintenance and conservation; as this is the first time that geochemical and downcore palaeoecological data have been presented from this lagoon.

Anthropogenic Changes in a Mediterranean Coastal Wetland during the Last Century—The Case of Gialova Lagoon, Messinia, Greece

“…Greece has lost more than 70% of its wetlands over the last 130 years due to policymakers having decided to drain lakes and coastal lagoons to increase agriculture land areas [1,2]. Further, the introduction of new mechanized technologies, the increased use of chemical fertilizers and pesticides, and governmental policies that favour maximizing production in agriculture, have impacted on soil and water resources, diminishing the benefits that wetlands provide [3,4].…”

“…These activities have resulted in severe environmental changes, leading to frequent dystrophic crises in the lagoon [9,10]. Several studies have focused on different physical and biological characteristics of the lagoon [1,[9][10][11][12][13][14][15][16]]. Yet, considering the lagoon is part of a larger wetland that provides important aquatic habitats within a Natura 2000 site, previous studies have neglected the neighboring wetland area and its surroundings.…”

Mapping shoreline changes over the years: The case study of Navarino bay, Pylos, Messenia, Greece

“…The east side wave-cut sea cliffs of Navarino bay were cut during this period. With variations in sea level and minor shoreline movements, the sand barrier existed by the time it was built and has survived to ourdays [10,18].…”

Μικροπαλαιοντολογική, Παλαιοοικολογική Και Τεκτονική Ανάλυση Του Ηφαιστειακού Κέντρου Σουσακίου Κατά Το Πλειόκαινο Και Το Πλειστόκαινο, Ανατολικός Κορινθιακός Κόλπος

“…Οικολογία: Απαντάται σε υφάλμυρα περιβάλλοντα (αλατότητα <33‰ Debenay et al, 1998) όπως π.χ. σε εκβολές ποταμών (Mazzini et al, 1999;Carboni et al, 2002;Amorosi et al, 2004, Curzi et al, 2006Rossi and Vaiani, 2008;Carboni et al, 2010, Avramidis et al, 2013, Avramidis et al, 2015. Περιγραφή: Κέλυφος τροχοσπειροειδές, στρογγυλωμένο περιφερειακά, με θαλάμους επίπεδους ή ελαφρώς διογκωμένους, ραφές επίπεδες έως ελαφρώς πεπιεσμένες, κοιλιακή περιοχή επίπεδη έως ελαφρώς κοίλη με 6 /8 θαλάμους, αστεροειδή ομφαλό που συνήθως γεμίζει με κοκκώδες υλικό.…”