These photos show how the sea along the south coast of England underwent discolouration over the hottest weekend of the year so far.

Sun-worshippers looking to enjoy a dip in the sea at Brighton yesterday were met with an English Channel that was an off-putting, dirty brown instead of its usual dazzling blue. 

However, it is likely to be algal bloom - a natural phenomenon in which phytoplankton start to reproduce in the warmer weather.

A murky brown coloured sea water off Brighton beach as crowds enjoy the hot sunny weather yesterday

The sea turns brown in Saltdean with what appears to be a viscous layer on the top of the water

When they begin to breakdown, they can often be mistaken for sewage - with brown foam appearing on the water's surface.

Pictures shared on social media yesterday showed swimmers bathing in the murky waters with Brighton's famous pier in the background.

Just up the coast, in neighbouring Saltdean, a similar phenomenon was videoed and posted on X - showing the sea also turning brown with what appears to be a viscous layer on the sea.