c89ee04f-1ba3-43c5-96f8-aabfdf83c5bb urn:uuid eng UTF-8 nonGeographicDataset nonGeographicDataset 2025-06-23T08:30:38 creation ISO 19115 2016 Soft sediment assemblages at Casey Station: Spatial variation and human impacts. (core samples: Oct-Dec 1997) c89ee04f-1ba3-43c5-96f8-aabfdf83c5bb A survey of macrobenthic assemblages in soft-sediments was done at Casey Station, East Antarctica. Samples were taken by divers using hand-held corers (core size - 10 cm diameter by 10 cm deep). The aims were: 1) To examine spatial variation at several scales in these assemblages; 2) To determine if there were differences between potentially impacted areas and control areas; 3) To determine the level of replication, taxonomic resolution and data transformation that are appropriate to studies of human impacts in Antarctic soft-sediment assemblages. Cores were collected by divers in a hierarchical, spatially nested design incorporating 4 scales: Locations (1000s of metres apart), Sites (100s of metres), Plots (10s of metres) and among replicates within plots (~1 metre). Four replicates for infaunal analysis were collected from each plot. Variation at the whole assemblage level was most significant at the largest scale: between Locations; but significant differences were also found between Plots within Sites, and between Sites within Locations. The impacted locations, near two waste tips, a sewage outfall and a wharf, as a group were significantly different to control locations. Impacted locations had less variable assemblages but more variable populations of dominant species than control locations. Control locations had greater richness and diversity than impacted locations. Patterns of assemblage structure were similar at fine (species and family) and medium (family to order) levels of taxonomic resolution but changed at coarse (phylum) levels of resolution. Assemblage patterns were similar between untransformed, square root and fourth root transformations but often different in presence/absence transformations. Concentrations of metals in sediments were also analysed and other environmental variables such as grain size and water depth were measured (two replicates from each plot). Multivariate correlations between the biological and environmental datasets were examined. Links to ASAC 1100. The fields in this dataset are: Location Site/Plot Replicate Antimony Arsenic Cadmium Chromium Copper Iron Lead Manganese Mercury Nickel Silver Tin Zinc Weight Toxicity {"type": "Polygon", "coordinates": [[[110.0, -66.34952], [110.53687, -66.34952], [110.53687, -66.25833], [110.0, -66.25833], [110.0, -66.34952]]]} 110.0 110.53687 -66.34952 -66.25833 AMD AMD/AU ANTIMONY ARSENIC ASSEMBLAGE BENTHIC CADMIUM CEOS CHROMIUM COMMUNITY COPPER CORE SAMPLES CORING DEVICES EARTH SCIENCE > HUMAN DIMENSIONS > ENVIRONMENTAL IMPACTS > CONTAMINANT LEVELS/SPILLS FIELD INVESTIGATION GEOGRAPHIC REGION > POLAR HUMAN IMPACT IRON LEAD LOCATION OCEAN > SOUTHERN OCEAN GET DATA documentDigital Download point for the data HTML PROJECT HOME PAGE documentDigital Public information for ASAC project 2201 HTML PROJECT HOME PAGE documentDigital Public information for ASAC project 1100 HTML VIEW RELATED INFORMATION documentDigital Citation reference for this metadata record and dataset HTML Creative Commons by Attribution logo documentDigital PNG