Indonesian Float Retrieval


One of the constant anxieties of technicians supporting the global ocean observing program Argo is their potential to be 'caught' in a fisherman's net at the surface while they upload their data to passing satellites.

For CMAR's Ann Thresher and her Hobart team of Bob Weldon and Alan Poole, that fear was realised last month when an Argo profiler (WMO 5901161) began reporting from land - having been picked up by an Indonesian troll-line tuna fisherman, Pak Anjas, in the Province of Papua, and returned to his fishing village near Jayapura.

Although Ann's preference was for it to remain at sea, the 'catch' was valuable - because rarely are the $30,000 profilers retrieved. They are mostly lost at sea, their batteries exhausted and unable to drive the profiler from a depth of 2 kilometres to the sea surface. Here was a chance to examine a profiler first deployed in 2003 north of Australia and that had provided 270 records for scientists of temperature and salinity conditions in the oceans to Australia's north.

A quick consultation revealed that Hobart colleague and fisheries scientist Craig Proctor had worked in the Jayapura area on two previous occasions, for tuna tagging and for a review of fisheries in Eastern Indonesia. Craig, already travelling to Indonesia this month for fisheries-related work and with the advantage that he speaks Indonesian fluently, landed the job of travelling to Jayapura to retrieve the profiler, handing over a reward and the thanks of the Argo team, and with the help of local Provincial fisheries staff boxing it up and returning it to Hobart.

"I'd been to Jayapura a couple of times before and we have made some great contacts there in Provincial Fisheries who were a tremendous help in tracking down the profiler and arranging to get it back to Hobart," said Craig. Having drifted in the ocean for seven years, expectations would normally be that the profilers would be a mass of weeds and barnacles. But because it resides for 95 percent of its life at a depth of one kilometre (below the depth where light penetrates), the profiler was virtually unmarked, apart from a scrape with the fishing vessel.

There are nearly 3,200 profilers in operation around the world's oceans, with few gaps still existing, apart from the icy southern and northern oceans, and a patch east of Somalia considered 'pirate' territory. Ann will soon have that covered as well, having arranged for a US naval vessel patrolling in the region to make deployments. Argo, a CSIRO Wealth from Oceans project, is a truly international program that cannot function without this sort of cooperation and help.