Is there a word in English to describe someone who wants to preserve a (minority) culture against erosion from a majority culture?

In Hong Kong there are many of us who want to preserve Hong Kong/Cantonese culture from erosion by CCP/mainland culture. For example, sometimes you can see a lot of mandarin around school kids rather than cantonese. The government is also pushing for schools to teach in mandarin rather than cantonese. Mandarin is the language...