Social media could have an impact on the Welsh language and erode cultural identity, a study has suggested.

Academics compared social media responses by 800 first-language Welsh and first-language English speakers aged 13 to 15 at Welsh-medium schools.

Nearly 70% of Welsh speakers used English "often" or "always" online with the majority using it more than Welsh.

Richard Jones, from Swansea University, said online language erosion could "threaten" cultural identity.

The findings have been published in the journal Trends in Psychology.

"Acknowledging the importance of language to minority-language speakers' cultural and social identities, the erosion of a language online would threaten the cultural identity of a nation," said Mr Jones, from the university's School of Psychology.

The study also evaluated the psychological impact of social media use on Welsh-English bilingual speakers.

The authors said the data suggested Welsh speakers' desire to use social media in Welsh might be driven by wanting to increase self-esteem, to attain greater linguistic parity with English speakers or to connect with other Welsh speakers.

Prof Phil Reed, also of Swansea University,, said the study showed "governments need to consider not only the impacts of social media on psychological health and wellbeing but also its impact on the cultures of minority groups who may be forced to abandon important and stabilising influences in the pursuit of digital interactions, which are becoming increasingly necessary for everyday life".

The Welsh government has set a target of a million Welsh speakers by 2050 but the number has fallen in the past decade, according to the latest census.