The NSW National Parks and Wildlife Service said there were only 50 breeding pairs between Wollongong and Batemans Bay in 2000, but the Shorebird Recovery Program had increased the population to 80 breeding pairs.

Terns lay their eggs in sand, seaweed, shells and rocks, which means beach-goers can easily trample their nests by mistake.

The chicks are also exposed to foxes, dogs and seagulls.

At less than 25cm long, the slender, migratory seabird is the smallest tern in the world.

Little terns have returned to to nest at Windang in recent years after an absence of more than 40 years.

Late last year signage and protective fences were erected around the Lake Illawarra entrance in a combined effort to protect the species.