How could warmer seas impact marine life in South West?
The sea water temperature in Plymouth Sound is some 3-4C higher than it should be at this time of year. It can be great if you want a swim or to surf, but what does it mean for the marine ecosystem and us? The sea around the UK and Ireland is now in a category 4 extreme heatwave, the categories run from 1-5, with 5 being above extreme. Sea surface temperatures globally in the last few weeks were higher than they have been since records started in 1850 . Changing sea surface temperatures affect the marine ecosystem - starting with the smallest plant and animal life in the ocean, the plankton. Plymouth Marine Laboratory (PML) studies the phytoplankton and zooplankton in our waters and has 30 years of data. Thirteen kilometres (8 miles) south of the city, a sensor samples the water, taking photos of the plankton and sending them back for analysis. Every day samples are tested and checked to see if there is anything out of the ordinary. Claire Widdecombe, a plankton ecologist at PML, said the higher temperatures were putting marine life under "thermal stress". "Some species may cope but others will not," she said. "There are also algal blooms that are harmful to us that can cause skin rashes, these are normally in the Mediterranean and are now off the west coast of Spain and Portugal." Higher water temperatures often lead to algal blooms (phytoplankton blooms), but sometimes these blooms die off, quickly leading to a sudden depletion of oxygen in the sea water. The net result is that marine life cannot breathe and die. This was seen earlier this month when thousands of dead fish, starved of oxygen, washed up along the Gulf Coast in Texas . The UK is not at that stage but, along with the changes to plankton, there could be changes to other marine species that feed off the microscopic life, such as jellyfish. A large smack of Moon jellyfish were recently spotted off Charmouth in west Dorset . The rise in sea temperature and the elimination of predators, such as sharks and tuna, has made conditions ideal. Moon jellyfish have a mild sting but some other species can be fatal such as the Portuguese man o'war, which can reach South West shores if the water is warm. Follow BBC News South West on Twitter , Facebook and Instagram . Send your story ideas to spotlight@bbc.co.uk. Sudden heat increase in seas around UK and Ireland Unexplained ocean warming alarms scientists Heatwaves 'instantly turn coral to ghosts' Plymouth Marine Laboratory Plymouth record label Fiftypointfour's Starchild track is a BBC Radio 1 hit Torquay road closed after van and motorbike collide Crash closes road in Devon village of Longdown 'Five years of needy columns - and Exmouth Food Bank' Plymouth swimmer tackles English Channel to help people with rare illness Dawlish historian: The history of Coastguards Cottages and the railway station Race against time to save Morocco quake survivors US denies Cold War with China in historic Vietnam visit How Russia and West agreed on Ukraine G20 language How Russia and West agreed on Ukraine G20 language US denies Cold War with China in historic Vietnam visit 'Everyone in this village is either dead or missing' At the scene of Morocco mosque collapsed by quake. Video At the scene of Morocco mosque collapsed by quake Inside the horror of Europe's biggest wildfire Inside a 'hijacked' South African building. Video Inside a 'hijacked' South African building How chronic pain feels for me. Video How chronic pain feels for me The rise and fall of a parenting influencer Guyana scrambles to make the most of oil wealth Florida's first hurricane-proof town The greatest spy novel ever written? Why is everyone crazy about Aperol? 2023 BBC.