Collection of large benthic invertebrates in sediment traps in theAmundsen Sea, Antarctica

Abstract. To study sinking particle sources and dynamics, sediment traps were deployed at three sites in the Amundsen Sea for one year from February/March 2012, and at one site from February 2016 to February 2018. Unexpectedly, large benthic invertebrates were found in three sediment traps deployed 130–567 m above the sea floor. The organisms included long and slender worms, a sea urchin, and juvenile scallops of varying sizes. This is the first reported collection of these benthic invertebrates in sediment traps. The collection of these organisms predominantly during the austral winter, and their intact bodies, suggests they were trapped in anchor ice, incorporated into the overlying sea ice, and subsequently transported by ice rafting. The observations imply that anchor ice forms episodically in the Amundsen Sea and has biological impacts on benthic ecosystems.