VERTICAL DISTRIBUTION AND BIOMASS OF MACROALGAE IN THE INTERTIDAL ROCKY SHORE OF TAJURA, LIBYA

Abstract

This study was an initial step toward understanding the qualitative and quantitative of macro-algae in the intertidal rocky shore of Tajura. In total, 24 species of macro-algae (6 Chlorophyta, 6 Phaeophyceae, and 12 Rhodophyta) were identified in the intertidal zone. All species were distributed to one or two of the three levels (high tide, mid tide, and low tide) except U. Linza, U. lactuca, C. compressa, H. muscifarmus, L. obtuse, and J. rubens which, were found in each level of the intertidal zones. Both mid and low tide was the main habitats for the growth, and abundance of seaweeds, most of them belonging to Rhodophyta. In contrast, high tide was less diversity and biomass, with a complete absence of Phaeophyceae. The total biomass in the study area was 158 g dw/m², whereas Rohdophyta had the highest biomass (94.8 g dw/m²). In addition, the biomass showed a clear difference between the three levels; the highest biomass (317.9g dw/m2) was observed in the low tidal zone and the lowest biomass (57.16g dw/m²)was observed in the high tidal zone. Finally, the annual dominant species by biomass in the intertidal rocky shore of Tajura were C. compressa (36.8g dw/m²) and L. obtusa (24.7g dw/m²).