You are not permitted to download, save or email this image. Visit image gallery to purchase the image.
John McGlashan College pupils (from left) James Phizacklea (10) William Archer (11) and Ryan Neill (10) work together to take a water sample at the Kaikorai estuary in Dunedin this week.
Assisted by the Otago Regional Council, the Department of Conservation and the Dunedin Environment Centre, the boys were among about 50 pupils from local schools who tested water quality, carried out a habitat survey and investigated what creatures could live in Kaikorai estuary and stream.
Dunedin Environment Centre co-ordinator Joseph Dougherty said the estuary's water quality had improved markedly since environmental laws tightened in the 1990s.
Twenty-three bird species could be found at the estuary, compared to just four in 1993.
Fish life had also improved.
The Kaikorai estuary and stream's importance as a living ecosystem was often overlooked, he said.
Otago Waste Services gave the schools access to the estuary.