‘Extreme’ marine heatwave expected for parts of UK with risk to sea life

A marine heatwave could reach “extreme” levels in parts of the UK later this week, raising concerns about marine life, according to the Met Office.

Prolonged sea heat can trigger mass die-offs among some seagrasses, shellfish and other species, as well as encourage greater numbers of warm-water creatures, including octopus.

The heatwave is currently strongest along the coasts of eastern and southern England and sea temperatures could rise 4-5 degrees above average in places.

The marine heat wave was fueled by long-term ocean warming due to climate change, as well as “heat domes” that caused record-breaking air temperatures in May and June.

Important marine habitats such as seagrasses and kelp forests are suited to colder waters and can experience high levels of heat stress when temperatures rise.

This can reduce their growth and even lead to mass mortality events; This can have knock-on effects on species that depend on these habitats.

The UK has previously experienced marine heatwaves (long periods of unusually high sea surface temperatures).

But scientists fear this event could be particularly intense and prolonged, especially for parts of the English Channel and the southern North Sea.

“We are now starting to see the temperatures we expected to see at the peak of summer, [at the] Late August,” said Dr Zoe Jacobs from the National Oceanography Center in Southampton.

“So if this continues, we could start to see serious impacts on ecological systems.”

Researchers have also noticed long-term changes in the UK’s marine life. Cold-adapted species such as cod have generally moved north, while some warmwater species such as octopus have increased in numbers around south-west England.

While natural cycles and fishing practices can affect the abundance of these creatures, many scientists point to the vital role of warming seas.