Growth Interruptions in Arctic Rhodoliths Correspond to Water Depth and Rhodolith Morphology

Coralline algae that form rhodoliths are widespread globally and their skeletal growth patterns have been used as (paleo-) environmental proxies in a variety of studies. However, interruptions (hiati) within calcareous skeletons regarded problematic this context. Here we investigated how hiati the Arctic from Svalbard archipelago correspond to environment morphology. Using X-ray micro-computed tomography stepwise model selections, found deeper waters subject more frequent hiatus formation. In addition, with higher sphericity (i.e., roundness) less often affected by such interruptions. We conclude these correlations mainly regulated hydrodynamics, because, waters, not turned frequently enough prevent dieback coralline algal thalli forming on underside rhodolith. coherence, spheroidal easily, therefore shortening amount time between turnover events. Moreover, incidence light is advantageous shallower where exhibit greater share surface diffused ambient light, thus enabling thallus also down-facing rhodoliths. consequence, information frequency formation combined rhodolith morphology might serve valuable proxy for (paleo-)environmental reconstructions respect availability hydrodynamic regime.