DOI: 10.5285/1f70d2a9-b0d7-4403-bcb9-2cd884222a9c
title: Conventional stomachs contents data for mesopelagic fish collected from the Scotia Sea between 2004-2009

description: This dataset comprises conventional stomachs contents data for the biomass-dominant species of mesopelagic fish, particularly myctophid fish (Family Myctophidae) in the Scotia Sea. The data were collected by depth-discrete RMT25 net trawls deployed between 0-1000 m between the Antarctic Polar Front and the South Orkney Islands. Samples were collected repeatedly at nominal sampling stations during austral autumn 2004, spring 2006, summer 2008 and autumn 2009 for analyses examining the trophodynamics of Southern Ocean mesopelagic fish and their role in the food web. The data are the quantitative measures of diet composition (prey abundance, frequency and mass) observed from microscope analyses of individual fish stomachs per species.
description: The data were collected across the Scotia Sea during austral autumn 2004 (JR100), spring 2006 (JR161), summer 2007/08 (JR177) and autumn 2009 (JR200) as part of BAS' Ecosystems Discovery 2010 project. The mesopelagic fish samples were collected with a RMT25 net deployed repeatedly between 0-1000 m at nominal sampling stations between the Antarctic Polar Front and the South Orkney Islands. Net deployments were performed during day and night on all surveys except JR200, where sampling was confined to the night. During each survey, stomachs from sub-samples of the biomass-dominant mesopelagic fish species were frozen at -20 degrees C for subsequent microscopic analysis back at the laboratory. Fish were sexed and staged where possible. This analysis involved the identification and quantification of the stomach's contents by microscopy. Where possible, prey items were identified to the lowest taxonomic level, typically species or genus level, and then enumerated and weighed to the nearest 0.01 g. Details on the survey sampling programmes are in the JR100, JR161, JR177 and JR200 cruise reports. An overview of the surveys, methods and results to date are also given in the publications below. Data were collected at the following approximate depth zones: 1: 0-200 m 2: 200-400 m 3: 400-700 m 4: 700-1000 m During a haul, a net was open for approximately 20-60 minutes in each depth zone. The net was towed obliquely at ~2.5 knots during this time. Collins MA, Xavier JC, Johnston NM, North AW, Enderlein P, Tarling GA, Waluda CM, Hawker EJ, Cunningham NJ (2008) Patterns in the distribution of myctophid fish in the northern Scotia Sea ecosystem. Polar Biol 31:837-851 Collins, M.A., Stowasser, G., Fielding, S., Shreeve, R., Xavier, J.C., Venables, H.J., et al. (2012). Latitudinal and bathymetric patterns in the distribution and abundance of mesopelagic fish in the Scotia Sea. Deep-Sea Research Part II-Topical Studies in Oceanography 59-60, 189-198. doi: 10.1016/j.dsr2.2011.07.003. Saunders, R.A., Collins, M.A., Shreeve, R., Ward, P., Stowasser, G., Hill, S.L., et al. (2018). Seasonal variation in the predatory impact of myctophids on zooplankton in the Scotia Sea (Southern Ocean). Progress in Oceanography 168, 123-144. Saunders, R.A., Collins, M.A., Ward, A.J.W., Stowasser, G., Hill, S.L., Shreeve, R.S., et al. (2015). Predatory impact of the myctophid fish community in the Scotia Sea (Southern Ocean). Marine Ecology Progress Series 541, 45-64. doi: 10.3354/meps11527. Shreeve RS, Collins MA, Tarling GA, Main CE, Ward P, Johnston NM (2009) Feeding ecology of myctophid fishes in the northern Scotia Sea. Marine Ecology Progress Series 386:221-236
description: 1. An RMT25 trawl (25 m2 mouth diameter, 5 mm minimum mesh size) 2. Motion compensated weighing scales 3. Binocular microscope 4. Calibrated laboratory weighing scales 5. Volumetric flasks Data were collected using an RMT25 trawl net as described in the publication and the SeaVoX Device Catalogue link below: Piatkowski, U., Rodhouse, P.G., White, M.G., Bone, D.G., and Symon, C. (1994). Nekton community of the Scotia Sea as sampled by the RMT 25 during austral summer. Marine Ecology Progress Series 112, 13-28. http://vocab.nerc.ac.uk/collection/L22/current/NETT0181/
description: Data have been checked for typographic errors and obvious outliers and were corrected on a few instances according to the original laboratory analysis records. The data are accurate and of a high quality within the confines of conventional stomach contents analysis techniques.