The conservation park was subsequently expanded to include the adjoining waters in order to control and manage berleying activities used to attract great white sharks.

Other features that contributed to the declaration include the small breeding population of Australian sea lions on the North Neptune Islands, Australian sea lion haul out areas on the South Neptune Islands and the breeding/nesting populations of Cape Barren goose, white-bellied sea eagle, osprey and peregrine falcon.

[4][3] The conservation park was subsequently extended in 1997 to include the waters within 2 nautical miles (4 km) of the shoreline of both the North and South Neptune Islands via a declaration under the National Parks and Wildlife Act 1972 to regulate and manage great white shark berleying activities around both groups of islands.

[7] On 29 November 2012, the waters within 2 nautical miles (4 km) of the coastline of both the North and South Neptune Islands at median high water also became part of a protected area known as the Neptune Islands Group (Ron and Valerie Taylor) Marine Park.

[11] Access for shark cage diving is via three operators licensed by the Department of Environment, Water and Natural Resources.