Fishermen in Cornwall say warmer waters are bringing with them species rarely seen around our coastline.
A new report says water temperature around the British coast is rising because of climate change and this is affecting marine life including the bluefin tuna.
Bluefin tuna were common in UK waters last century until the mackerel and herring they eat was overfished.
Since then there have been few sightings until recently when warm waters have brought back the fish they eat.
Dave Bond, a fisherman from Looe, recently took a trip out angling when a sixteen-year old enthusiast landed a blue fin tuna weighing 160 pounds.
Mr Bond agrees with the report that the shift in water temperature is the reason the tuna have returned.
Fishermen in the UK are not allowed to land blue fin tuna because the country has no quota for the fish, but Mr Bond says that this won't stop keen anglers from chasing the returning giants.
The report was published by the UK Marine Climate Change Impacts Partnership (MCCIP). It says that as well as tuna, squid and anchovies are returning to UK waters.