Octopus invasion hits UK amid extreme marine heatwave

Octopus invasion hits UK amid extreme marine heatwave reports a surge of octopuses in UK waters as a marine heatwave drives temperatures up as much as 5C above normal. Fishermen in Cornwall and Devon are reportedly seeing huge numbers along the coasts, with catches producing record profits. The UK is also bracing for what could be its longest heatwave in 50 years, with temperatures near 35C and conditions expected to last 14 days. Some fishermen are making more than £20,000 per week after hauling up to 20 tonnes. Britain’s fishing industry faces mixed outcomes: cod and haddock are moving northward toward cooler areas, while octopuses also consume lobsters and crabs. Cornwall has issued an emergency bylaw banning larger ships from using octopus pots because they trap other species. The octopus bloom began last year and intensified into 2026, reaching its highest level in 75 years, with about 3,500 tonnes caught last year and catches already surpassed by May.