Floating robots primed for release to capture elusive ocean data

Scientists will embark on a voyage across the Indian Ocean next week, distributing floating robots to gather data about the largely unknown biology of the ocean. For about 10 years 3,600 Argo free-floating sensors have been drifting around and gathering data about the temperature and salinity of the ocean. From next week a team of scientists will distribute updated Bio Argos, which can dive to 2,000 metres and gather previously unattainable data. Once they return to the surface data on biological indicators such as dissolved oxygen, nitrate, chlorophyll, organic matter and particles in the ocean are transmitted back to the scientists. The Australian and Indian science agencies teamed up on the project in early 2014. “The ship is leaving Jakarta tomorrow night, so we’re loading the floats on in Christmas Island over the weekend,” said the CSIRO project leader, Dr Nick Hardman-Mountford. “It’s then going to go across the Indian Ocean for about three weeks.” About a week into the journey towards Mauritius and Madagascar, the floats will be put in the water. “We hope to get the first data within a few hours of the Argo float being launched. It will be put into the water and start sinking straight away and complete its first cycle in a few hours. When we’ve got a few weeks of data we’ll start to look at it in a more scientific way. “For this trip we’re measuring chlorophyll, which tells us about the phytoplankton in the ocean. We do that by flashing a blue right at the phytoplankton and they flash back a red light at us. We can measure how much chlorophyll is there and measure how much algae life is there.” Other flashing lights will be used to measure the size of the phytoplankton and how many particles there are. Analysing this will give vital information about the makeup of the ocean. “All life in the ocean really comes from the amount of sunlight that’s turned into edible carbon by phytoplankton,” Hardman-Mountford said. “They are the meadows of the ocean. “Understanding these basic processes tells us how much carbon is being taken up by organisms and that relates to how much carbon dioxide gets taken up by the ocean, but also how much energy there is to go into the food webs of the ocean to sustain those ecosystems.” The east Indian Ocean is a resource-rich region and drives the climate of its surrounding area, home to more than 16% of the world’s population. Fishermen take from more than seven million tonnes of fish a year. “So it’s important that we keep track of what’s going on below the surface,” Hardman-Mountford said. The scientists will also examine eddies that spin off the coast of Western Australia and track north. CSIRO’s Dr Francois Dufois, who will be on the ship, has been studying the eddies for more than two years using satellites and models, according to Hardman-Mountford. “He’s tracked them with satellites coming from all the way of Western Australia across the Indian Ocean and as far as Madagascar. But the idea now is to get some of these robots into some of those eddies so we can really look at the processes as it goes along.” The voyage is part of a UN food and agriculture organisation voyage on the Norwegian research vessel Dr Fridtjof Nansen. The Bio Argo floats project is funded by the funded by the Department of Industry’s Australia-India strategic research fund, CSIRO Oceans & Atmosphere Flagship and Earth Observation Informatics Future Science Platform, the Indian government’s department of science and technology, and UN FAO.