Centuries-old nautical charts, mapped by long-deceased sailors to avoid shipwrecks, have been used by modern scientists to study loss of coral reefs.
A new US and Australian study – including research from The University of Queensland and the Australian Research Council Centre of Excellence in Coral Reef Studies - compared early British charts to modern coral habitat maps to understand changes to reef environments.
UQ’s Professor John Pandolfi said the study used information from surprisingly accurate 18th century nautical charts and satellite data to understand coral loss over more than two centuries in the Florida Keys.
“We found that some reefs had completely disappeared,” Professor Pandolfi said.
The study was led by Professor Loren McClenachan, Assistant Professor at Colby College, in Waterville, Maine, USA.
Professor McClenachan said more than half of the coral reef habitat mapped in the 1770s was no longer there. In some areas, particularly near land, coral loss was close to 90 per cent.
“We found near the shore, entire sections of reef are gone, but in contrast, most coral mapped further from land is still coral reef habitat today,” she said.
This estimate of change over centuries added to modern observations of recent loss of living corals.
The marine scientists measured the loss of coral reef habitats across a large geographic area, while most studies look more closely at the loss of living coral from smaller sections of the reef.
“We found that reef used to exist in areas that today are not even classified as reef habitat anymore,” Professor Pandolfi said.
“When you add this to the 75 per cent loss of living coral in the Keys at that finer scale, the magnitude of change is much greater than anyone thought.”
Continue reading at University of Queensland
Image via University of Queensland
