Unit:
Κατεύθυνση Βιολογική ΩκεανογραφίαLibrary of the School of Science
Author:
Oikonomou Aikaterini
Supervisors info:
Δρ. Διονύσιος Ε. Ραΐτσος, Αναπληρωτής Καθηγητής, Τμήμα Βιολογίας, ΕΚΠΑ,
Δρ. Μαρία Σαλωμίδη, Ερευνήτρια Β, Ινστιτούτο Ωκεανογραφίας, Ελληνικό Κέντρο Θαλασσίων Ερευνών.
Δρ. Γιάννης Ίσσαρης, Μεταδιδακτορικός Συνεργάτης Θαλάσσιας Οικολογίας, Ινστιτούτο Ωκεανογραφίας, Ελληνικό Κέντρο Θαλασσίων Ερευνών.
Original Title:
Comparative Study of Benthic Cover Estimation Methods from Macroalgal Photographic Samples
Translated title:
Comparative Study of Benthic Cover Estimation Methods from Macroalgal Photographic Samples
Summary:
Coastal macroalgal communities serve as valuable bioindicators of marine ecosystem status, and their monitoring through standardized methods is essential for large-scale monitoring programs, such as those developed under the EU Water Framework Directive. The aim of this study was to cross-compare different methods for analysing the presence and cover of macroalgae in 100 photographic samples from Greek seas, to identify the most suitable in terms of cost-effectiveness and reliability of results. Specifically, the precision, accuracy, and time efficiency of stratified random point intercept cover estimations at three modes of analytical effort (50, 100, and 150 points) were evaluated against reference (REF) total cover measurements obtained using a digitally superimposed grid. Additionally, these techniques were compared in practical application scenarios assessing the ecological status using the Ecological Evaluation Index continuous formula (EEI-c 1). The 150-point mode provided the closest mean Coverage Difference percentages to the REF method, while the 100-point mode yielded the best mean EEI-c Difference, and the 50-point mode required the shortest analysis time. Overall, the findings indicated that all three modes of the point intercept technique could effectively replace the REF methodology. The mode using 100 points offered the optimal balance between cost (in terms of analysis time) and reliability of results (in terms of precision and accuracy).
Main subject category:
Science
Keywords:
phytobenthos, macroalgal cover, image analysis, method comparison, biotic indices
Number of references:
103
