They are critically endangered and, because of the pollution in the River Derwent, live in majority at Ralphs Bay and its surrounding waters.

[1] Australia's first shore-based whaling station was established in Ralph's Bay at Trywork(s) Point.

Mr Collins brought a 100 ton of oil from Capt Moody of the King George, whaler, which she had caught since she had been in the river.

It met strong opposition from the local community which was concerned that the development would destroy native wildlife habitat in the area and reduce public access to the foreshore.

On 23 June 2010 the Greens announced the legal confirmation of the Ralphs Bay Conservation Area as being 171 hectares and therefore preventing proposed canal housing estates.