This is a mixed data set held in six excel files, containing processed acoustic backscatter data, mesopelagic fish abundance and swimbladder contents from night time sampled RMT25 nets, plus net catch data for all fauna combined and dominant mesopelagic fish in night time RMT25. Acoustic backscatter data is from 6 latitudinal acoustic transects spanning the Scotia Sea, obtained during cruises JR161, JR177, JR200, JR15002 and JR15004 (two transects). Data were collected using a Simrad EK60 echo sounder at 38 kHz. The EK60 was run continuously between Stanley (Falkland Islands) and Signy (South Orkney Islands). Fish data was collected using RMT25 night time net samples from 5 cruises JR161, JR177, JR200, JR15004 and JR16003. The data set focuses on 11 species of mesopelagic fish Bathylagus species, Cyclothone species, Electrona antarctica, Electrona carlsbergi, Gymnoscopelus braueri, Gymnoscopelus fraseri, Gymnoscopelus nicholsi, Krefftichthys anderssoni, Protomyctophum bolini, Protomyctophum tenisoni and Notolepis species. Abundance and proportion data was obtained for combined fish species, and identified by net tow and latitude. Biomass for all fauna and the 11 fish species was calculated from RMT25 night catch log data. Myctophid gas presence absence was determined from a combination of dissection, Computed Tomography and soft tissue X-ray. Funding was provided by the NERC grants NE/L002434/1 and bas010017. This data is embargoed until August 2019.
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.