DOI: 10.5285/62a44c8d-5593-4d2c-93d9-5ddfebcbfc36
title: Experimental measurements for replicate macrofaunal communities from the Western Barents Sea for summer 2017 and 2018

description: Measurements of benthic invertebrate particle reworking, bioirrigation, and associated nutrient concentrations used in the analyses by Solan et al. 2020 (Philosophical Transactions of the Royal Society A) for shipboard incubations of replicate macrofaunal communities from the Western Barents Sea during summer 2017 and summer 2018. Data were collected on cruises JR16006 and JR17007. Funding was provided by 'The Changing Arctic Ocean Seafloor (ChAOS) - how changing sea ice conditions impact biological communities, biogeochemical processes and ecosystems' project (NE/N015894/1 and NE/P006426/1, 2017-2021), part of the NERC funded Changing Arctic Ocean programme.
description: Data were collected from each of 5 stations in 2017 (B13-B17) and 6 stations in 2018 (B13-B17 and Xs) during two consecutive cruises (RRS James Clark Ross: JR16006, 30th June to 8th August, 2017; JR17007: 10th July to 5th August, 2018) following a transect along the 30°E meridian. At each station four replicate intact sediment cores (LWH: 20 x 20 x 12 cm) were obtained from replicate 0.1m2 USNL (Unites States Naval Laboratory) box cores using a core extruder, transferred to transparent acrylic aquaria (internal dimensions, LWH: 20 x 20 x 34 cm) and overlain with ~8 L (20cm depth) surface seawater (salinity, ~34). Aquaria (2017, n = 20; 2018, n = 24) were randomly transferred to one of two insulated fibreglass seawater baths (LWH: 1.2 x 1.2 x 0.8m, Tanks Direct, UK) and maintained at a representative ambient bottom temperature in the dark. Faunal mediated sediment particle reworking metrics were estimated after 12 days by establishing the redistribution of optically distinct particulate tracers (luminophores: 215g aquaria-1, fluorescent green, &lt;200µm silica sand, density 2.35 kg dm-3; Glass Pebbles Ltd., UK). The ventilatory behavior of the infauna (bioirrigation) was estimated from absolute changes in the concentration (10mM, 8.231g NaBr dissolved in seawater aquarium-1) of the inert tracer sodium bromide (Delta [Br-], mg L-1; negative values indicate increased infaunal ventilatory activity) over an 8 h period on day 12, determined using a Tecator flow injection auto-analyser (FIA Star 5010 series). Accumulated water column concentrations (µmol L-1) of NH4-N, NOx-N (i.e. NO3-N + NO2-N) and PO4-P were determined after 12 days incubation from standardized samples (taken from the centre of each aquarium at ~5cm depth, 0.45 µm NALGENE filtered) following standard protocols using a Lachat Quikchem 8500 flow-injection auto-analyser. Full descriptions and additional information provided in Solan et al. 2020 Phil. Trans. R. Soc. A. in main manuscript and supplementary information. Resolution: Particle redistribution resolution 83 µm in 2017 and 74 µm in 2018. Nutrient concentrations to two decimal places
description: Instrumentation: Canon 400D digital SLR camera Tecator flow injection auto-analyser (FIA Star 5010 series) Lachat Quikchem 8500 flow-injection auto-analyser
description: Standard protocols were followed and data entry double checked by independent person.