Antarctic pack-ice algal distribution : floe-scale spatial variability and predictability from physical parameters

This study was supported by the PACES (Polar Regions and Coasts in a changing Earth System) program (Topic 1, WP 5) of the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, the Helmholtz Virtual Institute „PolarTime“ (VH-VI-500: Biological timing in a changing marine environment — clocks and rhythms in polar pelagic organisms), the Helmholtz Alliance “Remote Sensing and Earth System Dynamics” (HA-310); and by the Australian Government through i) Australian Antarctic Science projects (4073, 4298), ii) the Cooperative Research Centres Programme through the Antarctic Climate and Ecosystems Cooperative Research Centre (ACE CRC), and iii) the Antarctic Gateway Partnership special research initiative through the Australian Research Council. All data used in this study are available through the Australian Antarctic Data Centre as well as PANGAEA (doi.pangaea.de/10.1594/PANGAEA.870706).Antarctic pack ice serves as habitat for microalgae which contribute to Southern Ocean primary production and serve as important food source for pelagic herbivores. Ice algal biomass is highly patchy, and remains severely undersampled by classical methods such as spatially restricted ice-coring surveys. Here we provide an unprecedented view of ice algal biomass distribution, mapped (as chlorophyll-a) in a 100m-by-100m area of a Weddell Sea pack-ice floe, using under-ice irradiance measurements taken with an instrumented Remotely Operated Vehicle. We identified significant correlations (p