Annual census targets spectacular sea slugs

Southern Cross University researchers will team up with members of the Combined Hunter Underwater Group and other underwater photographers from across the eastern seaboard, on Saturday (June 6) for the 7th seasonal Sea Slug Census in the Port Stephens area.

The region is internationally renowned for its huge diversity of shell-less marine molluscs (sea slugs), which include the amazingly colourful nudibranchs.

Associate Professor Steve Smith, from Southern Cross University’s National Marine Science Centre, said divers travelled from all over Australia and overseas to see and photograph the sea slugs at the various dive sites at Nelson Bay.

“We have been conducting censuses every three months since December 2013 to provide evidence to support our notion that Nelson Bay is an important
biodiversity hotspot in eastern Australia,” he said.

“The results to date confirm this, with more than 200 species identified from photographs taken during the census program and from historical images. Most of these have been seen along a very small stretch of coast.”

Professor Smith said that each census added more species to the list and generated greater awareness of our amazing underwater biodiversity and the need to manage it wisely.

“We are now attracting more than 40 divers for each census,” he said. “In March 2015, these divers added three species to the regional list and confirmed the presence of two introduced species that were first observed in the inaugural census in December 2013.

“Sea slugs have very rapid life cycles and they can respond quickly to changing environments so they have great potential as indicators of environmental health.”

Photo: The Splendid nudibranch - one of the sea slugs found in the Port Stephens area.