Visual Imaging of Benthic Carbonate-Mixed Factories in the Ross Sea Region Marine Protected Area, Antarctica

Abstract

Marine biogenic skeletal production is the prevalent source of Ca-carbonate in today’s Antarctic seas. Most information, however, derives from the post-mortem legacy of calcifying organisms. Prior imagery and evaluation of Antarctic habitats hosting calcifying benthic organisms are poorly present in the literature, therefore, a Remotely Operated Vehicle survey was carried out in the Ross Sea region Marine Protected Area during the 2013–2014 austral summer. Two video surveys of the seafloor were conducted along transects between 30 and 120 m (Adelie Cove) and 230 and 260 m (Terra Nova Bay “Canyon”), respectively. We quantified the relative abundance of calcifiers vs non-calcifiers in the macro- and mega-epibenthos. Furthermore, we considered the typology of the carbonate polymorphs represented by the skeletonized organisms. The combined evidence from the two sites reveals the widespread existence of carbonate-mixed factories in the area, with an overwhelming abundance of both low-Mg and (especially) high-Mg calcite calcifiers. Echinoids, serpulids, bryozoans, pectinid bivalves and octocorals prove to be the most abundant animal producers in terms of abundance. The shallower Adelie Cove site also showed evidence of seabed coverage by coralline algae. Our results will help in refining paleoenvironmental analyses since many of the megabenthic calcifiers occur in the Quaternary record of Antarctica. We set a baseline to monitor the future response of these polar biota in a rapidly changing ocean.

Spatial distribution of benthic flora and fauna of coastal placentia bay, an ecologically and biologically significant area of the island of newfoundland, atlantic Canada

“…CCA are even more tolerant of low-light conditions due to their low photosynthetic capacity (Littler et al, 1985;Roberts et al, 2002;Nelson, 2009). CCA are found within most coastal habitats (Littler et al, 1985), including (Zaneveld and Sanford, 1965;Schwarz et al, 2005;Castellan et al, 2021), and are observed at depths greater than any other local marine algae species (McConnaughey and Whelan, 1997). This may explain the exclusion of bathymetry from the CCA LightGBM model.…”

First records of Chionodraco hamatus nests in coastal areas of Terra Nova Bay (Ross Sea): a potential nesting area for the species?

“…Given the presence of sea ice (particularly fast ice) for most of the year, understanding of the coastal biogeography and ecosystem processes is limited to a restricted number of areas at depths accessible by dive-based operations (Cummings et al 2018). Such constraints are being overcome by the use of remote visual techniques, which are emerging as low-impact tools for collecting visual information on sh and benthic communities (Castellan et al 2021). In recent years, visual methodologies have been applied worldwide to improve current knowledge on the spatial patterns of biodiversity, substantially contributing to ecosystem monitoring and management of MPAs (Cappo et al2003;Jessop et al2022).…”