Epiphytic diatom communities onPhyllophora antarcticafrom the Ross Sea

Abstract

AbstractAntarctic seaweeds play an important ecological role, but the vast macroalgal beds, typical of the shallow-water zone, are not efficiently grazed. However, macroalgal thalli are covered by epiphytic diatoms which represent a rich food source for higher trophic levels. We describe the abundances, growth form structure, species composition and distribution patterns in the diatom communities associated withPhyllophora antarcticafrom selected sites within the Ross Sea. The goal of this work was to learn more about the relationships between various components of the epiphytic community and its habitat. To examine diatoms at the microscale, four relatively well described sampling sites were chosen and analyses were performed on a large number of diatoms. All observations and counts were made with the scanning electron microscope. Samples collected in the same season but from different sites and under different sea and ice conditions differed significantly in terms of species composition, but all represented abundant and well-developed diatom communities. A list of species associated withP. antarcticafrom the investigated area is provided and the influence of the sampling effort on the observed diatom diversity is assessed.