Seal numbers are on the increase with authorities saying they will soon be a common sighting on Sydney's foreshore and beaches.

Shona Lorigan from the Organisation for Rescue and Research of Cetaceans in Australia (ORRCA) says sightings are a good indication of improved water quality around the Harbour.

Ms Lorigan said sightings of seals had not been common in the area for the past forty years, with the species almost becoming extinct due to hunting in the 1800s.

The seal found around Walsh Bay in Sydney attracted many calls to the ORRCA hotline.

ORRCA is a volunteer organisation that rescues and monitors whales, dolphins, seals and dugongs.

For more information or to find out how to become a volunteer visit their website: