Bioerosion ichnodiversity in barnacles from the Ross Sea, Antarctica

Abstract Breakdown of skeletal and lithic hard substrates by organisms, a process referred to as bioerosion, is part the global carbon cycle receives increased attention, but little known about bioerosion in polar environments. Here, we study traces (addressed their respective ichnotaxa) recorded barnacle Bathylasma corolliforme from Ross Sea, Antarctica. Traces were visualized via scanning electron microscopy epoxy casts prepared with vacuum cast-embedding technique. In 50 samples shallow 37 m bathyal 1680 water depths, 16 different found, classified into microborings presumably produced cyanobacteria (1), chlorophytes fungi (9), foraminifera unknown organotrophs (5), macroborings cirripeds (1). Statistical ichnodiversity analysis resulted significant ( p = 0.001) ANOSIM moderate differences R 0.5) between microbioerosion trace assemblages at depths revealed two main clusters (NMDS, SIMPROF) corresponding photic aphotic stations. A comparison this Svalbard archipelago, Arctic Ocean, shows that calcareous skeletons similar waters both hemispheres. This includes several ichnotaxa are indicative for cool- cold-water environments, such Flagrichnus baiulus Saccomorpha guttulata . Nine investigated occur regions seven show an extensive bathymetrical range down deep sea depth.