Casey and Wilkes Stations marine eDNA and sediment chemistry study

This study collected sediments from 8 sites surrounding Casey and Wilkes Stations in the Windmill Islands, East Antarctica by inflatable rubber boat grab sampling in shallow (3-5m deep) nearshore sites over the summer season 2017-2018. eDNA was extracted from sediments (5 replicates per site plus field blanks) and sequenced for prokaryotic and eukaryotic organisms after amplification using 16S and 18S primers. Matched sediment samples were taken for sediment chemical analyses including metal content by diluted acid extraction (1M HCl, AEM), strong acid digestion (concentrated HNO3 and HCl to measure total recoverable metal content, TRM) and physicochemistry for particle size, organic carbon content, moisture content, nitrate, nitrite, and reactive phosphorous measurements.Each eDNA sediment sample has a corresponding set of chemical analyses including organic carbon content, moisture content, particle size distribution, reactive phosphorous, nitrate and nitrite, acid-extractable metal concentrations (ICP AES suite of metals), total recoverable metal concentrations (ICP AES suite of metals), and mercury. Each site also has corresponding DGT-labile metal fluxes (Chelex DGT suite of metals).Genomic DNA was extracted from a 10 g (wet weight) subsample of homogenized sediment using the DNeasy PowerMax Soil Kit (Qiagen, Germany) according to the manufacturer’s instructions, with the following modifications: the incubations with the C2 and C3 buffers were extended to 30 min and an additional wash with buffer C5 was performed. The extracted DNA concentration and purity was quantified using the Nanodrop 2000 spectrophotometer (Thermo Scientific, USA) at 260 nm, and determined to be sufficient (~4-15 ng/µL DNA). These extracts were amplified, sequenced, and are now stored at the Australian Antarctic Division.The first tab of the excel spreadsheet provides details about data in each tab. The OTUs from sequenced data following bioinformatics are given in the 16S and 18S labelled zipped files.The remaining sediment collected from each site was used to form mesocosms to which diffusive gradients in thin-films (DGT) samplers were deployed to measure labile metal fluxes from sediments to pore and overlying waters. This dataset provides all eDNA sequencing and analysis data, all sediment physicochemistry, and all sediment metal measurements. Descriptions of parameters and tabs are given on the first tab of the excel spreadsheet. Separately, the raw sequencing data and sequencing data after the bioinformatics pipeline are provided in a zipped file.This data set corresponds to project AAS_4326 field sampling campaign at Casey station in the 2017-2018 summer season. The dataset includes chemical investigations of sediment quality using various techniques as well as eDNA extraction and characterisation. eDNA extracts are stored at Australian Antarctic Division in Kingston, Tasmania, Australia. Contact Dr Cath King for access ([e-mail]).