World’s wetlands smaller

RESEARCHERS analysing more than one million satellite images have discovered 4000sq km of tidal wetlands have been lost globally over 20 years – but ecosystem restoration and natural processes have played a part in reducing total losses.

Nicholas Murray, senior lecturer and head of James Cook University’s global ecology lab, said globally, 13,700sq km of tidal wetlands had been lost, offset by gains of 9700sq km, leading to a net loss of 4000sq km over the two-decade period.

“We found 27 per cent of losses and gains were associated with direct human activities, such as conversion to agriculture and restoration of lost wetlands,” Dr Murray said.

“All other changes were attributed to indirect drivers, such as human impacts to river catchments, extensive development in the coastal zone, coastal subsidence, natural coastal processes and climate change.”

He said about threequarters of the net global tidal wetland decrease happened in Asia, with almost 70 per cent concentrated in Indonesia, China and Myanmar.