Flying fish - from Africa to the Amazon

Scientists have uncovered the natural fertiliser contained within Saharan dust that plays an important role in the health of the Amazon rainforest when it is blown across the Atlantic: fish bone. The research, involving researchers from the University of Leeds, Birkbeck, University of London, and the Diamond Light Source, is published on 25 September 2014 in the print edition of the journal Chemical Geology . The study analysed dust samples taken from the Bodélé Depression in Chad, in north-central Africa, which is the world’s largest single source of dust. Dr Caroline Peacock, an Associate Professor in the School of Earth and Environment at the University of Leeds, and a co-author of the paper, said: “We've shown that a significant proportion of the dust exported from the Bodélé region is made up of fossilised fish apatite – a mineral rich in fertilising phosphorus. This source of fertiliser is finite, because there are only limited amounts of fossilised fish material. So, over time, the amount of natural fertiliser that the Amazon receives will diminish. Previous research had shown that dust from this area is carried across the equatorial Atlantic and deposited on the Amazon, where it acts as a fertiliser.