19 September 2012

Researchers are examining tongue soles, eel gobies, nurseryfish and more at a workshop this week which aims to improve knowledge about estuarine fish in northern Australia.

The scientists are part of the Northern Australia hub of the National Environmental Research Program and are working with Northern Territory Museum Curator Mike Hammer and Curator Emeritus Helen Larson to identify species from Kakadu National Park.

Dr Brad Pusey, from the Australian Rivers Institute at Griffith University, said the samples were collected during recent field trips to the South Alligator River.

“On the most recent trip in August, our team spent two weeks sampling fish at 70 locations throughout the estuary and floodplain lowlands of the river, using a variety of netting and trapping techniques,” Dr Pusey said.

“What we’re finding is that many of the species found in freshwater across northern Australia are also present lower down in the river near the coast.

“Northern Australia is unique for its highly connected river systems and biodiversity, with some fish travelling hundreds of kilometres upstream from the river mouth.

“We believe that the high number of species present is largely a result of the absence of any dams or impediments obstructing flows from the headwaters to the ocean.”

Northern estuaries also contain many species that are restricted to estuaries and these are often important in food webs that support important commercial and recreational fisheries.

“The estuarine and coastal environments of northern Australia are important hotspots for food production, but rising sea levels from climate change will alter the makeup of these environments,” Dr Pusey said.

“Through this research we are hoping to get a better idea of which species are present and where, and subsequently which areas are the most important to conserve in their natural state.

“This workshop is a great opportunity to hear from some of the country’s fish experts about taxonomic principles, basic anatomy, sample preservation and curation.”

The researchers have been examining the fish in a laboratory at the Australian Institute of Marine Science, and comparing their samples with species catalogued at the Museum and Art Gallery of the NT in Fannie Bay, Darwin.