Changes in the fatty acid composition of Fucus virsoides J. Agardh in response to the type of substratum

Abstract

The effect of the substratum type (natural, limestone, or artificial, concrete) on the fatty acid composition of Fucus virsoides in six habitats around the harbours and beaches of the Istrian coast (northern Adriatic Sea) was investigated during the summer, the period of maximum development. All habitats of F. virsoides were regulated by very similar environmental factors and were exposed to moderate anthropogenic influences. F. virsoides growing on artificial substrata was characterised by lower concentrations of fatty acids, lower proportions of fatty acids among total lipids, higher C16:0/18:1 ratios (FA: 6.7±0.6 mg g^-1 d.w.; FA/TL: 22%; 16:0/18:1: 0.57±0.08) and an overall increase in saturation in comparison to communities growing on natural substrata (FA: 10.2±2.9–12.5±3.4 mg g^-1 d.w.; FA/TL: 30.8–33.7%; 16:0/18:1: 0.34±0.11–0.45±0.13). These results likely reflect the less favourable conditions for F. virsoides development on artificial substrates relative to natural substrates. The physiological processes of the algae growing on artificial substrata were more impaired with increasing age (FA: 1.9±0.6 mg g^-1 d.w.; FA/TL: 18.2%; 16:0/18:1: 0.68±0.08).