The Brown trout (Salmo trutta) has long been the UK's favourite freshwater fish. It lives in rivers and ponds and has been farmed to supply food and entertain anglers. This fishes' eggs, however, need a water temperature that's less than 12 degrees Centigrade to survive Spring spawning. It's estimated, that by 2080, river temperatures in the entire country will exceed that value. No more local Brown trout (https://www.theguardian.com/environment/2025/jan/31/brown-trout-britain-favourite-fish-at-risk-of-wipeout-within-decades-predicts-report). One should also note that temperature isn't the only thing endangering this fish. Most UK rivers are highly polluted with run-off from intensive farming and inappropriate treatment of waste water.
