Statistics released by the Scottish Fire and Rescue Service (SFRS) show a drop of 956 staff since the creation of the single fire service, from 8547 in 2013 to 7591 this year.
Of these, 667 were whole-time or retained firefighters while 289 were employed in support or control.
The staffing figures also show a 18 per cent drop in the number of volunteers between 2013 and 2016, from 417 to 342.
Scottish Liberal Democrat justice spokesman Liam McArthur raised concerns about the impact of the merger on the service.
He said: “Fire service staff across Scotland save lives every day. We need to ensure that they have the resources they need to do their jobs.
“Since the creation of SFRS, we have lost around 700 firefighters. These are not only full-time staff but also retained firefighters who provide front-line cover in almost every rural community.
“These figures underline the scale of the impact that SNP centralisation has had on our emergency services.
“We know that more job losses are coming, with plans for the closure of control rooms in the north of Scotland later this year. People have real fears over what this will mean for local knowledge and unions have warned of increased pressure on control and support staff.”
An SFRS spokesman said: “Our staffing numbers reflect our planned organisational structure to deliver our service effectively and efficiently right across Scotland.
“We inherited a range of crewing models from Scotland’s eight former services and work has been ongoing to standardise these. Our resource-based crewing model will ensure we have the staffing capacity and capability to deal with all incidents within our communities.
“We will be undertaking a whole-time firefighter recruitment campaign towards the end of 2016.
“As a national service, we are better placed to look strategically at the needs of the people of Scotland and deploy our resources where they are needed to ensure the safety of our communities across the country.”
A Scottish Government spokeswoman said: “The SFRS has worked closely with the Fire Brigades Union to achieve the right level of staffing to meet the needs of a modern service.
“There have been no station closures and SFRS operates a policy of no compulsory redundancies. A further recruitment campaign will also begin later this year.”