The CSIRO Staff Association has described the turnover as ''far too high'', and estimates it could cost the organisation more than $50 million a year in recruitment, training and lost intellectual capital.

Association president Michael Borgas said, ''We had been led by management to believe staff turnover was at an historic low. These figures clearly show that's not the case.''

The national science agency's chief executive Megan Clarke side-stepped several questions about future job cuts during a budget estimates economics committee hearing yesterday.

The CSIRO's executive head of environmental research, Andrew Johnson, was also tight-lipped in response to questions by Liberal senators about potential cuts to CSIRO's bushfire research.

''I will have to take that question on notice,'' he said.

The agency is finalising its 2010-11 budget this month, with staff at the Australian National Insect Collection in Canberra already warned to expect a 10 per cent budget cut and the loss of four taxonomy jobs. As previously reported by The Canberra Times, internal documents show a recent meeting of CSIRO's top executives discussed plans to shed 500 jobs across the organisation, driven by a bid to find savings of $10 million.

In response to questions by Labor senator Doug Cameron, Dr Clarke said CSIRO's staff turnover had dropped from 13.5 per cent to 10.4 per cent, with staff resignations dropping from 5.5 per cent to ''a low of 3.8 per cent''.

Dr Borgas said these figures ''came as quite a surprise'' to the staff association, which had recently been ''assured by management that turnover was at an all-time historical low''.

For more on this story, see the print edition of today's Canberra Times.