Crust Biometry of Hydrolithon Boreale (Rhodophyta: Hydrolithaceae) on Leave of Posidonia Oceanica Along a Mediterranean Coast Fed by Siliciclastic-Carbonate

Abstract

A study was conducted to estimate biometry of an epiphytic micro-calcareous red algae, Hydrolithon boreale found on leaves of a Mediterranean meadow, Posidonia oceanica along the entire Turkish coast of the Mediterranean Sea in time (winter and summer 2019) and space (regions, and bottom type and depth). Percent occurrence of the epiphyte was lower in winter (25%), particularly found in a small bay in the west than summer (44%), entirely along the coast. The epiphyte grew up to 5 mm in diameter, 0.35 mm in thickness of the crust size, and was populated up to 1006 ind/m2 in summer owing to the increased utilization of the carbonate by the epiphyte with the increased water temperature. The size was contrasted to the density (abundance and biomass) in space. The biometry was significantly dependent on the siliciclastic-carbonate deposition as inferred from SiO2 of the water in relation the leaf area index (LAI) of P. oceanica. Therefore, this deposition induced specimens growing in size, followed by the reduced density in relation to N-based nutrient of the water. Further major environmental parameters which negatively affected the biometry were pH and total suspended matter of the water, analogous to the turbidity. Of the trace elements, Ni was negatively correlated with the biometry whereas the LAI was however positively correlated with all the anthropogenic-sourced trace elements (V, Cu, Zn, As, Cd, and Pb) in the leaves. Of the bottom types, the calcite rock had higher density than the other soft bottoms in contrast to the size of the epiphyte.