Light Gradient and Moonlight Effects on the Ventral Calcified Stripes and the Thallus Aspects of Padina spp. on the Mediterranean Coast of Israel

Abstract

Light is an important abiotic environmental factor that dictates several dial, monthly and annual life patterns for most of the creatures on earth. Aside from its essential role as energy supporter of life on our planet, light may be dangerous and even deadly when overexposure occurs. Around the Israeli shores, intertidal organisms face high radiation most of the year, which exacerbated at ebb time due to desiccation. The Padina species, i.e., brown macroalgae inhabiting the Israeli abrasion platforms, seem to have means to protect themselves from excess light in such environments. They precipitate CaCO3 in the form of aragonite needle-shaped crystals arranged in concentric stripes located mainly on the ventral side of the frond. These ventral stripes cover the reproductive organs, which are located behind them on the dorsal side of the frond. The aragonite needle-shaped crystals in the apical stripes change to a flattened amorphous shape in older parts of the frond, probably due to wave erosion. We present here our results regarding the effect of light intensity and moonlight on rate of deposition of aragonite by the algae. It seems that from 19.6 μE to 380 μE the reflectance and the amount of CaCO3 are correlated and when there is more light-amount, there is more precipitation and more reflectance. Also, under full moon, the algae precipitate 40%wider stripes then under new-born moon. Citation: Benita M, Segman R, Iluz D, Dubinsky Z (2019) Light Gradient and Moonlight Effects on the Ventral Calcified Stripes and the Thallus Aspects of Padina spp. on the Mediterranean Coast of Israel. J Environ Sci Curr Res 2: 006.