Μελέτη των επιπτώσεων του ευτροφισμού στην οικολογική κατάσταση και τις οικοσυστημικές λειτουργίες του βένθους

• Main Authors: Dimitriou-Nikolakis, Panagiotis, Δημητρίου-Νικολάκης, Παναγιώτης
• Format: Doctoral or Postdoctoral Thesis
• Language: Greek
• Published: University of Crete (UOC) 2016
• Subjects: Θαλάσσια οικοσυστήματα; Οικολογία; Βένθος; Θαλάσσιος ευτροφισμός; Δείκτες οικολογικής κατάστασης; Marine ecosystem; Ecology; Benthos; Marine eutrophication; Indicators of environmental status; Φυσικές Επιστήμες; Γεωεπιστήμες και Επιστήμες Περιβάλλοντος; Natural Sciences; Earth and Related Environmental Sciences; Arctic; Antarc*; Antarctica
• Online Access: http://hdl.handle.net/10442/hedi/37086; https://doi.org/10.12681/eadd/37086

Eutrophication is one of the most visible examples of anthropogenic changes in the biosphere, affecting aquatic ecosystems from the Arctic to Antarctica. The European Water Framework Directive demands the achievement of “Good Environmental Status” form all EU member states by 2015. Additionally, the European Marine Strategy Framework Directive has led to the implementation of laws for the protection of the marine environment from eutrophication. In this context, benthic macrofauna provides a reliable indicator of ecosystem health and has been used extensively for assessing the ecological status of the ecosystem and for monitoring the effects of eutrophication on the costal marine ecosystem. This study adopted two different and independent methodologies: (i) meta-analysis of data in order to identify patterns in the behaviour of benthic systems related to the intensity of eutrophication and (ii) mesocosm experiments, that allow one to deflect the system from its initial conditions to an extent hard to do in nature and on the other hand to study the succession of the phenomenon over time under various conditions to the point of regime shift.In the context of the first methodology, a large data set from the Eastern Mediterranean was analyzed to explore the relationship between water column variables and benthic community status. The results showed a strong quantitative link between the water column variables (Chlorophyll a and Eutrophication Index) and various indicators describing benthic diversity and community composition. The percentage of benthic opportunistic species increased significantly in the stations with high trophic status of the water column and so did the strength of the coupling between values of seawater column and benthic indicators. The Eutrophication Index threshold level of 0.85, separating the “Bad and Poor” from “Moderate to High” conditions could serve as an acceptable critical value above which there is a readily observable change in benthic community composition.In the context of the ...