Refer to antFOCE report section 4.4.5 for deployment, sampling and analysis details. https://data.aad.gov.au/metadata/records/AAS_4127_antFOCE_Project4127 One camera and flash unit was mounted on the top middle section of each chamber to take one photo of the sediment every 30 minutes. The download file contains two folders with the photos taken from the 28th of January to the 23rd of February 2015 – one for Chamber A and one for Chamber C. A video time-lapse compilation of the Chamber A images is also included. Malfunctioning cameras deployed on Chamber A and C and on B and D during this same period and at other times, meant that no useful images were obtained. Background The antFOCE experimental system was deployed in O'Brien Bay, approximately 5 kilometres south of Casey station, East Antarctica, in the austral summer of 2014/15. Surface and sub-surface (in water below the sea ice) infrastructure allowed controlled manipulation of seawater pH levels (reduced by 0.4 pH units below ambient) in 2 chambers placed on the sea floor over natural benthic communities. Two control chambers (no pH manipulation) and two open plots (no chambers, no pH manipulation) were also sampled to compare to the pH manipulated (acidified) treatment chambers. Details of the antFOCE experiment can be found in the report – "antFOCE 2014/15 – Experimental System, Deployment, Sampling and Analysis". This report and a diagram indicating how the various antFOCE data sets relate to each other are available at: https://data.aad.gov.au/metadata/records/AAS_4127_antFOCE_Project4127

Metadata record AAS_4127_antFOCE_SedimentFauna contains all data sets relating to the fauna sampled from marine sediments during the antFOCE experiment, including macrofauna, meiofauna, diatoms, microbes, as well as DNA sequencing conducted on some of these groups and the results of a sediment bioturbation study. Refer to antFOCE report section 4.4 for deployment, sampling and on-station analysis details. https://data.aad.gov.au/metadata/records/AAS_4127_antFOCE_Project4127 Background The antFOCE experimental system was deployed in O'Brien Bay, approximately 5 kilometres south of Casey station, East Antarctica, in the austral summer of 2014/15. Surface and sub-surface (in water below the sea ice) infrastructure allowed controlled manipulation of seawater pH levels (reduced by 0.4 pH units below ambient) in 2 chambers placed on the sea floor over natural benthic communities. Two control chambers (no pH manipulation) and two open plots (no chambers, no pH manipulation) were also sampled to compare to the pH manipulated (acidified) treatment chambers. Details of the antFOCE experiment can be found in the report – "antFOCE 2014/15 – Experimental System, Deployment, Sampling and Analysis". This report and a diagram indicating how the various antFOCE data sets relate to each other are available at: https://data.aad.gov.au/metadata/records/AAS_4127_antFOCE_Project4127

Sediment Recruitment Experiment 4 (SRE4) was a large, long term (5 year) field experiment run at Casey Station (from 2001 to 2006) testing the effects of 4 different hydrocarbons on marine sediment ecosystems. Four different types of hydrocarbons were individually mixed with defaunated marine sediments and deployed in trays on the seabed at O'Brien Bay-1. Trays were collected after deployment periods of 5 weeks, 56 weeks, 62 weeks, 2 years and 5 years. In addition there was a bioturbation treatment using the burrowing urchin Abatus (at 56 weeks only). Samples were collected from 4 replicate trays of each treatment at each sampling time. Analyses were done of sediment hydrocarbon chemistry, microbial communities, meiofaunal communities, macrofaunal communities and diatom communities. The hydrocarbon treatments were: a synthetic Mobil lubricating oil; the same Mobil lubricating oil after 125? hours use in a vehicle engine; a Fuchs synthetic lubricating oil marketed as highly biodegradable; and Special Antarctic Blend diesel fuel (SAB). A control uncontaminated sediment treatment was used for comparison.

(SRE4) was a large, long term (5 year) field experiment run at Casey Station (from 2001 to 2006) testing the effects of 4 different hydrocarbons on marine sediment ecosystems. Four different types of hydrocarbons were individually mixed with defaunated marine sediments and deployed in trays on the seabed at O'Brien Bay-1. Trays were collected after deployment periods of 5 weeks, 56 weeks, 62 weeks, 2 years and 5 years. In addition there was a bioturbation treatment using the burrowing urchin Abatus (at 56 weeks only). Samples were collected from 4 replicate trays of each treatment at each sampling time. Analyses were done of sediment hydrocarbon chemistry, microbial communities, meiofaunal communities, macrofaunal communities and diatom communities. The hydrocarbon treatments were: a synthetic Mobil lubricating oil; the same Mobil lubricating oil after 125? hours use in a vehicle engine; a Fuchs synthetic lubricating oil marketed as highly biodegradable; and Special Antarctic Blend diesel fuel (SAB). A control uncontaminated sediment treatment was used for comparison.

Sediment Recruitment Experiment 4 (SRE4) was a large, long term (5 year) field experiment run at Casey Station (from 2001 to 2006) testing the effects of 4 different hydrocarbons on marine sediment ecosystems. Four different types of hydrocarbons were individually mixed with defaunated marine sediments and deployed in trays on the seabed at O'Brien Bay-1. Trays were collected after deployment periods of 5 weeks, 56 weeks, 62 weeks, 2 years and 5 years. In addition there was a bioturbation treatment using the burrowing urchin Abatus (at 56 weeks only). Samples were collected from 4 replicate trays of each treatment at each sampling time. Analyses were done of sediment hydrocarbon chemistry, microbial communities, meiofaunal communities, macrofaunal communities and diatom communities. The hydrocarbon treatments were: a synthetic Mobil lubricating oil; the same Mobil lubricating oil after 125? hours use in a vehicle engine; a Fuchs synthetic lubricating oil marketed as highly biodegradable; and Special Antarctic Blend diesel fuel (SAB). A control uncontaminated sediment treatment was used for comparison.

Sediment Recruitment Experiment 4 (SRE4) was a large, long term (5 year) field experiment run at Casey Station (from 2001 to 2006) testing the effects of 4 different hydrocarbons on marine sediment ecosystems. Four different types of hydrocarbons were individually mixed with defaunated marine sediments and deployed in trays on the seabed at O'Brien Bay-1. Trays were collected after deployment periods of 5 weeks, 56 weeks, 62 weeks, 2 years and 5 years. In addition there was a bioturbation treatment using the burrowing urchin Abatus (at 56 weeks only). Samples were collected from 4 replicate trays of each treatment at each sampling time. Analyses were done of sediment hydrocarbon chemistry, microbial communities, meiofaunal communities, macrofaunal communities and diatom communities. The hydrocarbon treatments were: a synthetic Mobil lubricating oil; the same Mobil lubricating oil after 125? hours use in a vehicle engine; a Fuchs synthetic lubricating oil marketed as highly biodegradable; and Special Antarctic Blend diesel fuel (SAB). A control uncontaminated sediment treatment was used for comparison.

Sediment Recruitment Experiment 4 (SRE4) was a large, long term (5 year) field experiment run at Casey Station (from 2001 to 2006) testing the effects of 4 different hydrocarbons on marine sediment ecosystems. Four different types of hydrocarbons were individually mixed with defaunated marine sediments and deployed in trays on the seabed at O'Brien Bay-1. Trays were collected after deployment periods of 5 weeks, 56 weeks, 62 weeks, 2 years and 5 years. In addition there was a bioturbation treatment using the burrowing urchin Abatus (at 56 weeks only). Samples were collected from 4 replicate trays of each treatment at each sampling time. Analyses were done of sediment hydrocarbon chemistry, microbial communities, meiofaunal communities, macrofaunal communities and diatom communities. The hydrocarbon treatments were: a synthetic Mobil lubricating oil; the same Mobil lubricating oil after 125? hours use in a vehicle engine; a Fuchs synthetic lubricating oil marketed as highly biodegradable; and Special Antarctic Blend diesel fuel (SAB). A control uncontaminated sediment treatment was used for comparison.

A total of 701 still images were analysed from 10 transects on the Sabrina Coast continental shelf. Imagery was collected from the RVIB Nathaniel B Palmer (NBP 14-02, 29 January - 16 March 2014) across a greater than 3000 km2 area. A 'yoyo' camera, with downward facing digital still and video cameras mounted within a tubular steel frame, was deployed on a coaxial cable to image the seafloor. The Ocean Imaging Systems DSC 10000 digital still camera (10.2 megapixel, 20 mm, Nikon D-80 camera) was contained within titanium housing. Camera settings were: F-8, focus 1.9 m, ASA-400. An Ocean Imaging Systems 3831 Strobe (200 W-S) was positioned 1m from the camera at an angle of 26 degrees from vertical. A Model 494 bottom contact switch triggered the camera and strobe at 2.5m above the sea floor, imaging ~ 4.8m2 of sea floor. Parallel laser beams (10 cm separation) provided a reference scale for the images. Transects were conducted at a ship's speed of ~1 knot. Still images were characterised for main taxonomic groups and sediment properties based on the CATAMI scheme of Althaus et al. 2015.

Sediment Recruitment Experiment 4 (SRE4) was a large, long term (5 year) field experiment run at Casey Station (from 2001 to 2006) testing the effects of 4 different hydrocarbons on marine sediment ecosystems. Four different types of hydrocarbons were individually mixed with defaunated marine sediments and deployed in trays on the seabed at O'Brien Bay-1. Trays were collected after deployment periods of 5 weeks, 56 weeks, 62 weeks, 2 years and 5 years. In addition there was a bioturbation treatment using the burrowing urchin Abatus (at 56 weeks only). Samples were collected from 4 replicate trays of each treatment at each sampling time. Analyses were done of sediment hydrocarbon chemistry, microbial communities, meiofaunal communities, macrofaunal communities and diatom communities. The hydrocarbon treatments were: a synthetic Mobil lubricating oil; the same Mobil lubricating oil after 125? hours use in a vehicle engine; a Fuchs synthetic lubricating oil marketed as highly biodegradable; and Special Antarctic Blend diesel fuel (SAB). A control uncontaminated sediment treatment was used for comparison.

Sediment Recruitment Experiment 4 (SRE4) was a large, long term (5 year) field experiment run at Casey Station (from 2001 to 2006) testing the effects of 4 different hydrocarbons on marine sediment ecosystems. Four different types of hydrocarbons were individually mixed with defaunated marine sediments and deployed in trays on the seabed at O'Brien Bay-1. Trays were collected after deployment periods of 5 weeks, 56 weeks (one year), 62 weeks, 2 years and 5 years. In addition there was a bioturbation treatment using the burrowing urchin Abatus (at 56 weeks only). Samples were collected from 4 replicate trays of each treatment at each sampling time. Analyses were done of sediment hydrocarbon chemistry, microbial communities, meiofaunal communities, macrofaunal communities and diatom communities. The hydrocarbon treatments were: a synthetic Mobil lubricating oil; the same Mobil lubricating oil after 125 hours use in a vehicle engine; a Fuchs synthetic lubricating oil marketed as highly biodegradable; and Special Antarctic Blend diesel fuel (SAB). A control uncontaminated sediment treatment was used for comparison. A randomised block design was used with a tray of each treatment in 24 blocks (5 trays per block). Four blocks were sampled at each time (4 trays of each treatment). Meiofauna Two replicate cores were taken from each tray at each time. Copepods were identified to family. Nematodes were identified to genus. Data is from one, two and five years of the experiment. At one year there is only one replicate per tray for copepod data (a total of 4 replicates per treatment).