Supervisors info:
Αδαμάκης Σ. Ιωάννης – Δημοσθένης, Επίκουρος Καθηγητής, Τμήμα Βιολογίας, Εθνικό και Καποδιστριακό Πανεπιστήμιο Αθηνών (ΕΚΠΑ)
Τσιρίκα Αναστασία, Εργαστηριακό Διδακτικό Προσωπικό, Εργαστήριο Ιχθυοκομίας – Αλιείας, Τομέας Ζωικής Παραγωγής, Τμήμα Γεωπονίας, Αριστοτέλειο Πανεπιστήμιο Θεσσαλονίκης (ΑΠΘ)
Faulwetter Sarah, Συνεργαζόμενη Ερευνήτρια, Τμήμα Γεωλογίας, Πανεπιστήμιο Πατρών
Translated title:
Dynamic impact of seasonality on the meadows of the seagrass Cymodocea nodosa in the areas of Epanomi, Thessaloniki and Vravrona, Attica.
Summary:
The seagrass meadows are among the most significant marine ecosystems globally and have important functions of high ecological and socio-cultural balance, affected by both natural and anthropogenic disturbances. The seagrass Cymodocea nodosa (Ucria) Ascherson, an indigenous plant of Mediterranean Sea, is noted for its rapid adaptability to changing environmental conditions. Seasonality constitutes a fundamental form of environmental change, shaping its population and growth. The objective of this work is to evaluate the impact of seasonal variations on the characteristics of the marine angiosperm Cymodocea nodosa in the areas of the European Natura 2000 network in Epanomi Thessaloniki (code GR1220012, Thermaikos gulf, North Aegean sea) and Vravrona Attica (code GR3000004, Petalioi gulf, South Aegean sea).
After annual field and laboratory analyses of phenological and physiological characteristics of the two meadows, along with environmental parameters of the coastal zone where they thrive, strong seasonality was observed (p<0.05). Specifically, variations were noted in their features between warm and cold periods, influenced also by local factors in each area. During the warm period, higher values of growth, biometric characteristics (density, leaf area, dry biomass), starch levels, biomass of reproductive organs, and epiphyte coverage were observed, while during the cold period, growth slowed down, and defense mechanisms (increased pigment concentrations, phenolic compounds, sugars) and underground biomass were strengthened. Additionally, abiotic conditions of the areas varied due to geographical location, climatic conditions, and anthropogenic pressures. In particular, the Epanomi area exhibited higher levels of turbidity, phytoplanktonic chlorophyll-a and nitrate concentrations, while Vravrona was characterized by intense hydrodynamic action, factors that may contribute to the formation of different reproduction and growth patterns (Epanomi: sexual reproduction and normal meadow, Vravrona: clonal propagation and patchy meadow). In conclusion, the seagrass Cymodocea nodosa has developed adaptive mechanisms that allow it to cope with seasonal changes and survive in a wide range of environmental conditions. Ultimately, the importance of continuous conservation efforts and management of these ecosystems, considering local parameters, is crucial for ensuring their integrity and to understand - and predict - their future changes.
Keywords:
Cymodocea nodosa, Seasonality, Seagrass, Epanomi, Vravrona, Aegean sea, Natura 2000
