The river Thames is the largest river that is wholly in England, with a total length of 354km.River Thames is "severely polluted with plastic" and Thames was declared 'biologically dead' in 1957, bird and marine mammal species living in and around the river have increased greatly. The Thames is increasing in temperature at an average of 0.2°c each year, which can damage ecosystems and wildlife stocks by causing creatures to adapt their habits and ranges. Water levels are also rising in the Thames — at Silvertown, there's been an average increase of 4.26mm per year since 1990, which contributes to the threat of flooding in London.

River Thames is "severely polluted with plastic Researchers estimate that 94,000 tiny pieces of plastic - called microplastics - flow down the river every second in some places.water from washing machines finds its way into the river and contains extremely small fibres from clothes; plastics contained in sewage also wash into the water; and parts of larger bits of plastic, such as bottles and packaging items, get washed into the river too. Researchers think plastic gloves and masks used by people during the coronavirus pandemic could make the problem worse.

Mammals like porpoises, seals and over 100 species of fish could be in danger after a series of studies by researchers from London's Royal Holloway University determined that the Thames. Estimates that 115 species of fish can be found in the estuary too London, had some of the highest densities of microplastics found in any river in the world.

Factorie - Some factories are releasing chemicals into the river.