Sediment characteristics of samples from the Chatham Rise, Southwest Pacific

We examined changes in environmental parameters following an experimental benthic disturbance using a modified plough (estimated 15 cm penetration) on the Chatham Rise (~450 m depth), Aotearoa/New Zealand. Sediment core retrievals were undertaken using an Oceans Instruments MC-800 multicorer fitted with six 70 cm long polycarbonate core tubes with 9.52 cm internal diameter that took place pre-disturbance on 16-17 June 2019 (voyage TAN1903), post-disturbance on 24-25 June 2019 (TAN1903) and one-year post-disturbance on 14-19 June 2020 (TAN2005). In order to determine any background changes in the larger surrounding area between years (2019, 2020), an additional reference site with similar hydrographic and sediment attributes (REF, depth = 455 m), located approximately 15 km to the north-west of the Butterknife (Figure 1B), was also sampled in the pre-disturbance period (n = 2, TAN1903) and one-year post-disturbance (n = 3, TAN2005). Multicores were sliced into 0-1 cm and 1-5 cm layer fractions and analysed for bacterial cell abundance, water content, grain size distribution, particulate organic carbon, particulate nitrogen, total organic matter, and chlorophyll a and phaeopigment content.