A team of NSW Department of Primary Industries (DPI) Fisheries and SEA LIFE Sydney Aquarium experts has successfully caught and relocated a critically endangered Greynurse shark local had affectionately named 'Bruce'.

READ MORE: Lake Conjola shorebird volunteer fears backlash over council claims

DPI Program Leader Shark Strategy and Threatened Species, Marcel Green led the operation and said non-lethal SMART drumlines were deployed late on Tuesday night to catch the shark.

The lines were deployed from a boat near the southern boat ramp, Mr Green said.

"The shark was quickly caught and transported by road to Ulladulla in a custom-built shark transfer crate supplied and managed by SEA LIFE Sydney Aquarium.

READ MORE: Lake Conjola's Greynurse shark healthy and not in distress: NSW DPI

"The shark was then carried out in a trawler from Ulladulla Harbour and safely released offshore."

Mr Green said weeks of planning had gone into the operation, which was scheduled to take place last month but postponed due to bushfires in the area.

"We made the decision to move the shark due to concerns over dropping water levels and rising water temperatures in the lake, and we became concerned for the shark's welfare," Mr Green said.

"We also know there are far more visitors to the area over the summer holidays, so swimmer-safety played a significant part in our decision to relocate the shark."

Greynurse sharks are listed as a critically endangered species in the NSW Fisheries Management Act 1994.

A dead Greynurse shark was taken away from Lake Conjola's entrance on Wednesday, July 3.

Two reasons may have caused its death, a NSW DPI spokesperson said.

"It was not possible to provide a precise cause of death for the shark; hooks were found in the stomach and there was evidence of bacterial infection,both of which may have contributed to the death."