Ethological analysis of the trace fossil Zoophycos: hints from the Arctic Ocean

The distribution of the trace fossil Zoophycos in Quaternary marine sediments from the Arctic Ocean was studied in twelve piston and gravity cores retrieved during the Swedish icebreaker expeditions YMER80, Arctic Ocean- 96 and LOMROG I & II. The sampled cores span an area from the Makarov Basin to the Fram Strait. Zoophycos was only found in two cores taken at more than 2 km water depth on the slope of the Lomonosov Ridge, but was absent in cores obtained at shallower depth, confirming earlier observations of the trace maker's bathymetric preferences. The two cores containing Zoophycos are characterized by quiet sedimentation and slightly enhanced food flux compared with the general Arctic. The occurrence of Zoophycos in these cores in a setting that is characterized by extreme seasonal variations in food flux due to the total ice coverage during winters and high primary productivity during the long summer days, is interpreted to be a cache- behaviour response to pulsed flux of food to the benthic realm.