Day 2: Welcome to Bass Strait
By: Simone Burzacott-Gorman
The development of complex scientific models, in this case, the collection of accurate oceanographic and meteorological data, from multi-beam sonar was gathered to produce high resolution nautical charts (maps) of the ocean floor, requiring collaboration from many sources and across many disciplines. We were exposed to first-hand experience of 21st century, contemporary, collaborative science.
Today, Investigator, travelled to the survey site in Bass Strait to commence bathymetry mapping of the ocean floor. In Australia, the Hydrographic Office is responsible for the surveying and production of nautical charts. Navy personnel along with CSIRO and Geoscience Australia personnel worked together to calibrate the ship’s sonars over SS Queensland, a known and well surveyed wreck just beyond the reaches of the survey site. The calibration test enabled the hydrographers to find the zero point for their instrumentation (multi-beam sonars) by aligning pitch (up and down of the boat), roll (side to side of the boat) and yaw (snaking from front to back) of the vessel, thereby eliminating ‘bow tying’ (the shape of interference at the edges of the imagery) prior to using the instrumentation to gather primary data. In order to survey the transect area, a high degree of specialised physics and mapping systems enable high resolution mapping up to 75m depth, travelling at 8 knots over a 1500 square kilometre area.
The collected data will be used by a vast array of organisations including the hydrographic commission to produce interactive nautical charts for shipping, but also by other researchers aboard Investigator. Interestingly, the same data will be used for a very different purpose by Dr Eric Woehler, principal investigator of seabird at sea research project on RV Investigator and honorary research associate for the Institute of Marine and Antarctic Studies, University of Tasmania and Conveyor of Bird Life Tasmania, who will access ship data to better understand the behaviour of albatross when feeding and interacting at sea. Dr Woehler explained that, ‘we have a very good understanding of where our birds live and breed in Australia, and we even know how many there are in specific locations, what we don’t know is how they interact with other birds or other species at sea. With some 10, 000 species of birds in the world (give or take), there are only 300 species of seabirds. 70% of the Earth’s surface is covered with water and that oceanic environment can only support 3% of the worlds birds, which suggests life at sea is harsh for seabirds. Our primary goal on Investigator is to build a better understanding of the associations between seabirds and features of the ocean through the ships oceanography equipment. We are looking for correlations between current, current convergence, sea temperature and bird interaction’. Dr Woehler is committed to gathering baseline data as sea conditions and its inhabitants alter due to changing global atmospheric and oceanic temperatures. This snapshot reflects the growing value of collaborative scientific inquiry, poignantly testimony to the value of an interdisciplinary approach to data collection, distribution and dissemination.