Water bugs indicate health of Top End lagoon

Charles Darwin University environmental management students have collected aquatic insect and plant samples at a unique lagoon outside Darwin to determine its health status.

The nine Master of Environmental Management students collected dragonfly and damselfly larvae, beetles, water mites and other macroinvertebrates during the recent fieldtrip to Girraween Lagoon.

Aquatic ecology lecturer Dr Erica Garcia said the samples helped students to determine the health of the lagoon, whose year-round stable water levels made it unique to the region.

“Macroinvertebrates are good indicators of the lagoon’s ecosystem health,” Dr Garcia said.

“For the most part, students found that these samples indicated the lagoon was in good condition.”

She said the field trip aimed to strengthen students’ skills in environmental management and in assessing the quality of tropical wetland ecosystems.

“Wetlands are extremely valuable ecosystems that support a range of wildlife and plants,” Dr Garcia said.

The students were introduced to methods commonly used to assess aquatic health, including sweep nets to capture insects, water quality meters and quadrats to sample vegetation surrounding the lagoon.

The field trip has been held annually since 2004.