Antarctic Seabed Assemblages in an Ice-Shelf-Adjacent Polynya, Western Weddell Sea

• Published in: Biology
• Main Authors: Frinault, Bétina A. V., Christie, Frazer D. W., Fawcett, Sarah E., Flynn, Raquel F., Hutchinson, Katherine A., Montes Strevens, Chloë M. J., Taylor, Michelle L., Woodall, Lucy C., Barnes, David K. A.
• Format: Text
• Language: English
• Published: MDPI 2022
• Subjects: Article; Antarctic; The Antarctic; Weddell; Weddell Sea; Antarc*; Ice Sheet; Ice Shelf; Ice Shelves
• Online Access: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9774262/; https://doi.org/10.3390/biology11121705

SIMPLE SUMMARY: One-third of the Antarctic continental shelf is covered by ice shelves, floating extensions of the Antarctic Ice Sheet. Marine life beneath and bordering ice shelves is rarely investigated, yet likely to be highly impacted by climate change. As ice shelves retreat, marine environments transition into new open-water spaces, with potential for primary production and consequent food-fall to the seafloor. How Antarctic seabed assemblages (benthos) develop in such emerging spaces is influenced by neighboring and oceanographically-connected communities; thus, closing knowledge-gaps of benthic biodiversity near ice shelves underpins understanding of future ecosystem change. This study examined seafloor assemblages, and environmental differences, in a region that has experienced ice-shelf retreat, in a polynya adjacent to a marine margin at the forefront of climate change: the ice-shelf front. The study area, located in the Weddell Sea, is seldom accessible, and lies within a proposed international marine protected area. The study found a physically- and biologically-diverse seabed, complexity in potential environmental influences, and evidence of increasing megafaunal densities with increasing distance from an ice-shelf front. This research provides insights into seafloor habitats and inhabitants close to an evolving marine margin, and establishes ecological baselines from which biological responses to climate change can be evaluated to inform marine management. ABSTRACT: Ice shelves cover ~1.6 million km(2) of the Antarctic continental shelf and are sensitive indicators of climate change. With ice-shelf retreat, aphotic marine environments transform into new open-water spaces of photo-induced primary production and associated organic matter export to the benthos. Predicting how Antarctic seafloor assemblages may develop following ice-shelf loss requires knowledge of assemblages bordering the ice-shelf margins, which are relatively undocumented. This study investigated seafloor assemblages, by taxa and ...