Faroe Islands
First of all, let's start with the country itself. The Faroe Islands is a self governing, archipelago under the Kingdom of Denmark. It's located in the between Iceland and Norway. Approximately +90% of the country's wealth comes from fishing.
As we all know, the world as a whole is getting more polluted every second. For this country, if the sea get's too polluted, the fish obviously aren't good enough to eat. If the fish aren't edible, the country as almost no ways of making money, and this would cause a financial crisis, and thus completely devastating the country.