Meeting Abstract
Benthic communities of the Antarctic shelf are comprised of a diverse assemblage of species typically dominated by invertebrates, particularly echinoderms, sponges, and ectoprocts. In some zones of the Antarctic shelf ectoproct abundance is significant, creating ‘garden-like’ habitats that harbor numerous other species. As the combined forces of global warming and ocean acidification threaten these communities, we sought to characterize the ectoproct gardens using direct benthic sampling (Blake Trawls) and two techniques for imaging the sea floor (YoYo camera and OFOS video systems). Blake trawls and YoYo cam transects of the Bellingshausen, Amundsen, and Ross Seas were conducted during a research cruise on the R/V Nathaniel B. Palmer in 2013. The OFOS imaging of the seabed in the Weddell Sea was part of the DynAMO project during the PS96 cruise of the R/V Polarstern in 2015-16. Species identifications of ectoproct samples were completed using SEM. The areas of ectoproct gardens were measured from the images using the Trainable Weka Segmentation plugin developed for FIJI software. Sites in the Ross Sea contained ectoproct gardens dominated by flustrid species with finely mineralized skeletons, and to a lesser extent by other lepraliomorph and umbonulomorph species having more robust mineralized skeletons. Although ectoproct gardens in Weddell Sea also contained flustrid species, ectoproct species with more heavily mineralized skeletons were more abundant. Combined with species identifications from our fixed samples, the quantification of various morphological grades of ectoprocts was facilitated by the better-resolved images created through the OFOS video system.
