The CANYONS voyage on RV Investigator aimed to investigate past and present processes governing the flow pathways, formation and geochemical signatures of Antarctic Bottom Water (AABW) off Cape Darnley, East Antarctica. The proposed survey area was focussed on the Wild and Daly canyons and the adjacent sediment drifts - the Daly and ‘Armand’ drifts. The survey aimed to collect systematic multibeam bathymetry and sub-bottom profiles across the region to support collection of long sediment cores (up to 24 m), Kasten cores and multicores, CTDs (conductivity- temperature-depth instruments) and deep towed camera transects This dataset reports analyses of samples collected from the surface uncontaminated "underway" seawater supply on R/V Investigator. The samples were collected while the ship transited from Perth to Cape Darnley. A suite of samples were collected in order to characterise surface ocean particles across the oceanographic gradients that characterise the Southern Ocean. these data were generated by IMAS Honour student Veda Surapaneni, and were included in her honours thesis.

The CANYONS voyage on RV Investigator aimed to investigate past and present processes governing the flow pathways, formation and geochemical signatures of Antarctic Bottom Water (AABW) off Cape Darnley, East Antarctica. The proposed survey area was focussed on the Wild and Daly canyons and the adjacent sediment drifts - the Daly and ‘Armand’ drifts. The survey aimed to collect systematic multibeam bathymetry and sub-bottom profiles across the region to support collection of long sediment cores (up to 24 m), Kasten cores and multicores, CTDs (conductivity- temperature-depth instruments) and deep towed camera transects. This dataset reports analyses of particulate organic carbon and biogenic silica from two CTD casts conducted in the Cape Darnley region. The voyage was terminated after a medical evacuation so only two CTD stations were occupied. These data were generated by IMAS Honour student Veda Surapaneni, and were included in her honours thesis. The dataset also includes hydrochemistry, DIC, Alkalinity and pigment data generated by CSIRO, although these data are published in other national repositories and reproduced here for completeness and convenience only.

Biologically relevant macronutrients, nitrate + nitrite, silicate, phosphate and ammonia, were measured at all sites throughout the study. Nitrate + nitrite values (NOx) at the surface showed clear seasonal trends, peaking over winter and drawing down to near zero in summer and autumn. Phosphate concentrations also reached a peak in winter, which was associated with Southern Ocean influence. Median ammonium concentrations at all sites were generally <0.5 μM, with no clear peaks in any season or month. Overall, the lowest values were measured in August and other months showed reasonable spread around the median. Median silicate concentrations were consistently highest at sites 1 and 9, followed by site 5. Water from the River Derwent flows through site 1, then tracks east towards site 9 then site 5. Seasonally, silicate was generally highest in winter when the River Derwent outflow is also greatest.