‘Extreme’ sea temperatures expected for parts of the UK at risk to marine life

According to the Met Office, sea temperatures could reach “extreme” in parts of Britain this week, posing a threat to marine life.

Prolonged sea temperatures trigger mass die-offs among some seagrasses, shellfish and other species, as well as encourage many warm-water creatures, including octopuses.

The heat wave is currently strongest along the east and south coasts of England, and sea temperatures are likely to reach 4-5C above average in places.

Marine heat waves are triggered by “heat domes” that bring high temperatures in May and June, on top of long-term ocean warming caused by climate change.

Important marine habitats such as sea grass and kelp forests are adapted to colder waters and can experience severe heat stress as temperatures rise.

This can slow their growth or even cause mass die-off events, which can have knock-on effects for species that rely on these habitats.

The UK has experienced ocean warming – prolonged periods of unusually high sea surface temperatures – before.

But scientists fear this event could be particularly powerful and long-lasting, particularly for the English Channel and parts of the southern North Sea.

Dr Zoe Jacobs, of the National Oceanographic Center in Southampton, said: “We are now starting to see the temperatures we would expect to see at the height of summer (end of August).

“So if this event continues to occur … we may start to see some serious impacts on ecosystems.”

Researchers have also noticed Long-term changes in UK marine life. Cold-adapted species such as cod are generally moving north, while some warm-water species such as octopus have increased in south-west England.

Although natural cycles and fishing practices can affect the abundance of these creatures, many scientists point to a significant role of warming oceans.