Scientists to launch bio robots in Indian Ocean to study its ‘interior biology’

Australia’s science agency has teamed up with its Indian counterpart to release bio robots into the Indian Ocean in order to “revolutionise” our knowledge of a marine environment upon which hundreds of million of people rely. There are already 3,600 so-called Argo floats – free-floating sensors – drifting around for a decade gathering data about the temperature and salinity of the ocean. “But it’s just the physics,” the CSIRO’s Dr Nick Hardman-Mountford told Guardian Australia. “What we don’t understand is the interior biology of the ocean – what’s driving the food webs and how carbon is being taken up.” Advanced versions of the Argo floats will provide scientists from the CSIRO and the Indian National Institute of Oceanography (CSIR-NIO) real-time data on “dissolved oxygen, nitrate, chlorophyll, dissolved organic matter and particle scattering” to further understand specific ecosystems. “[We can] target biology and chemistry as well as the physics,” he said. The floating sensors will dive to different depths and report back via satellite. While the current, non-bio Argo floats stop at 1000m and 2000m for several days before returning to the surface, the new sensors will spend a lot of time around the 200m depth, studying the information-rich plankton species, before diving to 1000 and 2000m levels. “Understanding the plankton at the base of the food web ... is important because everything else in the ocean feeds off plankton,” said Hardman-Mountford. Key questions the scientists will be examining include how the eddies that spin off the WA coast into the interior of the Indian Ocean transport that coastal water and how that feeds the production in the interior, said Hardman-Mountford. “We know they can go as far as Madagascar but we don’t know how long that lasts for. Also in the northern Indian Ocean … in the Arabian Sea and the Bay of Bengal they have low oxygen waters, and they seem to be increasing in the Bay of Bengal.” As well as questions around climate change, there are also food, energy and health security issues that need investigation. “The Indian Ocean rim countries make up one sixth of the world’s population. A lot of people rely on it,” said Hardman-Mountford. “About half the world fishers live in the eastern Indian Ocean, catching about 7m tonnes of fish per year. It’s the third-largest tuna fishery in the world with an estimated value of $2-3bn a year. It’s a really economically important region. "By studying the Indian Ocean in this detail, we can investigate the origin and impact of marine heatwaves like the one that devastated the coral reefs and fisheries off north Western Australian in 2011 – and improve our prediction of them in the future." The $1m bio Argo floats project is funded for three years, in part by the Australian government under the Australia-India Strategic Research Fund.