Fewer than half the primary pupils who learn through immersion Gaelic progress to similar courses in secondary.
This year, five fewer secondaries are providing Gaelic-medium education, according to the latest national statistics drawn up by Boyd Robertson of Strathclyde University.
Mr Robertson, senior lecturer in Gaelic at Strathclyde, reports that 106 of the 226 pupils (47 per cent) who left primary last summer have moved on to GME classes this session.
Overall, there are 91 fewer secondary pupils learning through Gaelic, down to 284 from 375.
But the downturn is balanced by a rise in the number of secondary pupils who are prepared to learn Gaelic as a second language without following the full immersion route.
Numbers are up from 2,370 in 2002-03 to 2,513 in 2003-04. In contrast, the number of fluent speakers among secondary students has dipped slightly from 997 to 974, a decline of 23.
In the secondary sector, schools in the Western Isles dominate the table for the largest number of pupils in fluent speaker classes. The Nicolson Institute in Stornoway has 168 pupils learning Gaelic in such classes and Lionacleit in Benbecula has 113.
For Highland, Portree High in Skye has 145.
In the earlier stages, the number of pre-fives learning Gaelic has risen from 361 to 623 - up 262 - while the primary figures are up 47, from 1,925 to 1,972. Two more primaries are providing GME taking the total to 60.
But the general decline in pupil numbers is reflected in the fall in P1 where 314 pupils enrolled this session against 339 last year.