Voyage 7 of the Nella Dan, 1984-1985 - Voyage report and acoustics log

The dataset download contains scanned copies of the acoustics log and the voyage report from voyage 7 of the Nella Dan in the 1984-1985 season. The voyage departed Hobart on the 9th of February, 1985, and conducted marine science, as well as stopping at Davis, Mawson, Edgeworth David and the Shackleton Ice Shelf before returning to Hobart on the 17th of March, 1985. See the download file for full details, but some extracts from the voyage report are copied below. Report on Voyage 7 - Marine Science on Nella Dan, Malcolm Robb Due to the cancellation of the fishing and current meter components, the marine science program was redefined as a study of bird distribution and feeding habits as related to oceanographic phenomena. This program would utilise a towed body containing CTD instrumentation in conjunction with the hydroacoustic measurement of "food". In addition a second CTD could be used from the stern using one of the partly operating trawl winches. The study design A cruise plan was designed in which the collection of bird distribution data was given priority; hydroacoustic and oceanographic data were collected to complement the bird observations. Tide Gauges Two Annderra type tide gauges were to be deployed on behalf of the Victorian Institute of Marine Science (VIMS); one at Mawson and one at Davis. Observations of seabirds and marine mammals during voyage 7 - Jennifer A Bassett Seabird observations Systematic seabird observations were conducted from the MV Nella Dan during voyage 7. This was the third voyage during the 1984/85 austral summer when seabird observations were conducted by the same observer. To record distribution and abundance of seabirds during all voyages standard ten minute counts were used following the method outlined in the Revised Edition (February 1984) of BIOMASS handbook #18 (1982). On voyage 7, as in the previous voyages, observations were made where possible during all hours of daylight. A minimum of one count per hour was made. Within the Australian BIOMASS Study Area (defined as the region 58-90 degrees East, and South of 59 degrees) standard counts were usually made twice hourly with a more or less continuous record being kept to record the occurrence of less common species, large flocks and feeding behaviour. The distribution and abundance of seals and cetacea were also recorded. A total of 380 10 minute counts were made during the voyage, 205 of these within the Australian BIOMASS Area. Hydroacoustic program report for voyages 5 and 7, 1984/85 - Ian Higginbottom During voyage 7, the new EK-400 echosounder and QD were used in conjunction with the so called 'spare' 120 kHz hull mounted transducer. The echosounder was run along 4022 miles of cruise track between 17 Feb - 11 Mar 1985. Data were recorded on punch tape for only 1248 miles of cruise track in the Prydz Bay Scullin-Monolith region.