The numbers are well below those of the UK, which is aiming to improve its record of a 47% take-up in languages at GCSE.
But the Education Committee said that while languages were an important part of the curriculum, they were optional subjects and part of the choices available to pupils.
Unlike core subjects such as English and maths, it is not mandatory to study a language at key stage 4.
‘This is important so that young people have as much flexibility as possible to study the subjects that most interest them, or align with their future study or career ambitions,’ said a spokesman.
UK education authorities are concerned about low take-up of language courses, particularly with commerce saying it needs candidates with better language skills.
Former Accent Language School owner Anna Lisa Detassis was not surprised by the statistics.
‘It’s difficult to motivate English speakers to learn another language when the whole world speaks English, but only knowing English is not always enough and being able to speak another language can help you stand out to employers across many different industries,’ she said.
‘It’s also been proven to stimulate brain development. Once you learn one language it gets easier from there.’
Mrs Detassis said the fall in the number of students taking a foreign language was down to a combination of factors, including languages now being a GCSE option, and a limited offering.
At States schools currently 150 pupils in a GCSE cohort of 462 are studying a language – 113 studying French, 21 taking Spanish and 16 learning German.
More than a third of this total are at Les Beaucamps High School, where 54 of 116 pupils are studying French.
36 of 100 La Mare de Carteret pupils are studying a language, 29 choosing French and seven opting for Spanish.
At St Sampson’s High, 27 students out of 152 are preparing for a language GCSE – 17 in French and 10 in German.
Five of the six GCSE students at St Anne’s School in Alderney are studying French, while 28 pupils of 88 at Les Varendes are studying a language, including eight French, 14 Spanish and six German.
In the UK, there are more than 310,000 entries are in modern language GCSEs. This is just less than half of the number of pupils at the end of Key Stage 4, though some may take more than one modern language.
Twenty-five years ago about 86% of pupils took a foreign language exam.
These figures come from a recently published Language Teaching in Schools briefing for the UK government raising concerns about the drop.
It highlighted that language learning in England was consistently poor. There have been regular calls from UK industry and educational bodies for the levels of attainment to be raised.
The UK government has previously set out plans for most pupils to be required to take a GCSE in a modern language under plans for the English Baccalaureate.
Education, Sport & Culture spokesman said there had been a lot of work recently across secondary schools to align the languages curriculum, and resulted in a large increase at Les Beaucamps.
‘We’re hopeful that trend continues but again emphasise that the focus is on student choice.’
Mrs Detassis called on parents to emphasise the importance of learning another language to their children.
‘It’s a life skill and just as important as other school subjects, in a global world, not being able to speak another language puts us at risk of being isolated and moving backwards.’