Waters surrounding UK gripped by prolonged marine heatwave

Northwest European waters are currently experiencing an extreme marine heatwave, with sea surface temperatures (SSTs) reaching record highs for April and May since satellite monitoring began in 1982.

This event, now lasting over two months, is significant due to its intensity and persistence. Current sea surface temperatures are warmer by up to 4°C west of Ireland, and by 1.5-2.5°C around the UK coastline: temperatures are what we would usually expect around mid-June. 

The heatwave is the result of several overlapping factors. Prolonged high-pressure systems brought a dry, sunny spring and weak winds and waves, creating ideal conditions for warming. This means the sea started to warm mid-February, one month earlier than usual. Additionally, the waters around the UK were already warmer than usual coming out of winter, a trend that has been building over the past 40 years, with an average increase of 0.3°C per decade. 

READ MORE: Why has spring been so warm and dry so far this year?

A key feature of marine heatwaves is the formation of a warm layer at the ocean’s surface. This layer acts like a lid, trapping heat near the surface and preventing it from mixing into deeper, cooler waters. It can be compared to a layer of olive oil floating on water, this thin surface layer allows heat from solar radiation to accumulate near the surface. When this layer forms, surface temperatures can increase fast: the last 9 days have seen a sudden additional 1°C warming.  

Marine heatwaves in UK waters usually last around two to four weeks. This year’s event began early March and has continued into May, making it one of the longest on record for this time of year. The North Sea has already peaked in temperature, while areas west of Ireland and the Celtic Sea are currently experiencing their highest levels. 

This prolonged warming can amplify land heatwaves by reducing the cooling effect of sea breezes and by altering rainfall patterns. Dr Jonathan Tinker, marine climate scientist, said: "With projections suggesting UK summer sea temperatures could rise by up to 2.5°C by 2050, such events are likely to become more frequent, intense and longer-lasting. Marine heatwaves offer a glimpse into how changing ocean conditions could shape future weather conditions."

READ MORE: Met Office Weather Deep Dive: A change is on the way

Cooler weather and stronger winds expected over the weekend are likely to ease the marine heatwave. With temperatures dropping and westerly winds picking up, the stable “olive oil” surface layer may begin to break down, allowing cooler water to mix in and gradually reduce sea surface temperatures. 

Centre for Environment, Fisheries and Aquaculture Science (CEFAS), Plymouth Marine Laboratory (PML) and The National Oceanography Centre (NOC) are keeping a close eye on what this means for our ecosystems and fisheries. Met Office is bringing together the UK and Irish research community with Defra at Reading University on 22nd May to discuss science and research ongoing in UK marine heatwaves. 

Keep up to date from the Met Office with weather warnings, the latest forecast on their website, on YouTube, or follow them on X and Facebook, as well as on their mobile app.

The EU Reset Deal – Cornish Fish Producers’ Organisation reaction

 

The Labour Government’s manifesto does not mention the fishing industry, and since its time in power, it’s hard not to believe it was left out for good reason. In the short space of 10 months, we have seen nothing but taking away any hint of opportunity from the UK fishing industry and its surrounding coastal communities, and it’s now a wonder what else can Keir Starmer do to make more of a mess of our industry.

The UK-EU reset deal struck on the 19th May is as far away from the CFPO’s priorities as could be imagined. At least thirteen more years of guaranteed access for the EU fleet, all the way up to the six mile limit, no change in quota shares, and absolutely nothing in return that will mean anything for a fisherman on the deck of a boat.

How could this go so wrong when the UK held the most powerful card in the pack. Automatic access for EU fleets to fish in UK waters was scheduled to expire in June 2026. That card was surrendered on 19th May 2025, as the UK sought trade and other benefits from the post-Brexit deal. The lack of direct engagement from those at the very top who were responsible for making this deal is evident in the outcome. The CFPO priorities were clear and simple and not at all unreasonable, and not one has been met, or even come close.

For all of the hard work that Cornish fishermen have put in to shaping up the new post Brexit world under the UK Fisheries Act, attending countless meetings to ‘co-design’ new fisheries management plans, it all feels rather pointless given the outcome of this new trade deal. The lack of future opportunity the deal holds for our fishing businesses, our coastal communities, our next generation of fishermen, let alone our ability to manage our own seas will beg the question of any fisherman, why bother getting involved in fishing policy and politics ever again. Especially knowing that the EU will be marking our homework every step of the way. How far we are from being a true independent coastal state?

But allocating blame brings limited benefit. Realistically, there was always going to be a multi-year access deal for EU fleets. The geopolitics of the moment just do not allow for a bad-tempered breach between the UK and the EU at this juncture. It is the government’s complete failure to secure any quid pro quo in fishing terms that is breathtaking.

An exclusive 12mile limit would have marginal impacts on French, Belgian and Dutch fishing businesses but would have meant a great deal for the fishers struggling to make a living off the Southwest coasts.

A transfer of quota of stocks where there is an acute shortage (rather than paper fish) would have made a significant difference and would have signalled that this is a government that actually cares about fishing and was committed to securing its future.

When placed alongside the challenges ahead over fleet displacement by offshore renewable, this deal gives grounds to wonder.

But the world changes. Ukraine and Trump are proof of that. Any threat to an island nation’s food security would force a rapid change of priorities. That too is a thought worth considering.

In the meantime, the fishing industry will wonder how much of the £360 million allocated to the Fishing and Coastal Growth Fund is ‘new money,’ how it will be spent, over what time period, how much will be siphoned off, and how much will go to support genuine fishing businesses and communities.

As so much in these negotiations and this reset deal, so much remains opaque.

Attenborough's Ocean - what it didn't say.

 

Fine #FishyFriday in May

Make the most of the weather today, change is on the way...

in addition to all the inshore fleet, fish from 11 boats filled the market this morning for the final market of the week...

with plenty of hake from west of Scilly...

and head-on mink from the prawn boats...

theres no ;et up on the octopus 'bloom' as it is called by scientists...

some cracking red mullet from the seiner...

with so many boxes leaving hardly any room to move...

its turbot time for the netters that fish with tangle gear...

and Dover time for some of the beamers not chasing 8-leggers...

there's two sides to every turbot tale...

a nice clean box of grey gurnard...

yet more of the beast from the Med...

and more...

the fish in Bay 3...

was wall-to-wall with boxes...

and yet another two box cod trip...

there's blue gold luking in there somewhere...

the point of no return for many small shellfish that succumb to the huge tentacles of these guys as they move towards the UK...

the inshore boys are enjoying the mackerel challenge...

prawners, crabbers and netters between trips...

young Sam swinging the spiders ashore...

Vision V...

Lily Anna just two of the big prawn boats working from Newlyn on this year's langoustine season...

though the grounds can prove a challenge with the wreckage still strewn all over the seabed in the Western Approaches

leading to some serious damage of trawls, this net with a missing belly and much more...

but its all smiles from the crew even though they have two days ahead of them on the quay...

putting the trawl...

 back together...

which currently fills the entire end of the quay...

in addition to the prawn boats...

a Scottish scalloper is also working from the port...

that's one way to counteract the big tide and keep the boats afloat in the harbour...

the guys who work boats of this size had nothing to shout about after the EU deal that was announced earlier this week, nothing to protect fishing inside 12 miles as they had hoped...

as restoration work work continues to bring the old quay back into use; fishing from the medieval Old Harbour was first recorded 670 years ago in 1355...

after the deal with the EU that was signed over this week one wonders if the harbour will still be a place recording fish landings in 670 years time?

 

Newlyn harbour post EU fisheries agreement announcement.

Gus Caslake from Seafish on the market this morning talking greater weaver and why the dorsal fins have been removed......

Newlyn is renowned for its diversity of fish, Couch's bream...

and those aforementioned Greater Weavers being but just two examples...

it takes two to tango...

they keep coming...

white fish from the visiting Scottish prawn trawlers made up a ig part of this morning's market offering...

a grader in action...

Newlyn is lucky enough to have Andy Reed, outgoing Fishing News editor, paying his first visit to the fish market as he puts together this year's 'Newlyn Special' feature - his final assignment before heading off on ventures anew - a big 'thank you' from the industry to Andy for such a sterling job over the years at the helm of the UK's only national weekly fishing trade paper, now in its 111th year!..

"it was this big!" says Nigel after a morning on the handline...

Barry and one of his mates, Sid the spider crab...

much of Newlyn shellfish is still exported to the EU - farmed salmon is now the biggest fish by weight of consumption in the UK, according to some, more than all other fish put together.

 

UK-EU Summit: Fisheries APPG to Meet to Scrutinise Fisheries and Related Deals

Historical context: Cornish and other Fishermen in the House of Commons demanding a 12 mile exclusive limit - in 1980!

 The All Party Parliamentary Group (APPG) on Fisheries and will meet tomorrow 20 May to scrutinise all aspects of the UK-EU deal on fisheries, outlined today as part of the UK-EU Summit in London.

The APPG has been collating priorities for future UK-EU fishing arrangements since January, ahead of next year’s expiration of the Trade and Cooperation Agreement’s (TCA) adjustment period on fisheries. With the Government promising to secure the 'best possible outcome' for UK fishermen and women, the UK’s fishing industry was clear on their ask – that fishing would not again be made a totemic issue, to be traded against other areas.

As clearly set out in the APPG’s 2022 report, the original Brexit deal on fisheries was poorly perceived by industry for failing to live up to Government promises, quota gains that fell short of expectations, and continued access for EU vessels to UK waters. The impacts of that deal were felt at sea and on land.

From the perspective of the industry, the expiration of the adjustment period on fisheries presented an opportunity to rebalance what was felt as a poor deal on fisheries, with access to the UK’s rich waters a key point of leverage to achieving this. For businesses exporting to the EU, frictionless trade was cited as paramount. Safeguarding sustainable management of fisheries, including of non quotas species like scallops and crab were also cited as crucial.

Amidst confirmation of a twelve year deal on fisheries access, the APPG will be scrutinising the details of agreements announced today, and their implications for the long term sustainability of the UK’s fishing communities and fisheries, alongside the wider seafood sector.

As part of this, the APPG will be scrutinising the SPS deal which promises to reduce red tape for UK seafood businesses exporting to the EU and reopen key markets for live shellfish. APPG Members will also be pressing for details of supports to industry in the face of any agreed arrangements, including relating to the £360 million Fishing & Coastal Growth Fund announced today.

APPG Co-Chair Alistair Carmichael MP said, “A twelve year deal on fisheries indicates that fishing has once again been treated as a second class concern and is deeply disappointing. With the expiry of the fisheries deal adjustment period there was an opportunity to revisit and undo some of the difficulties of the Brexit deal.

"Indications that fishing has been traded for a deal in another area does a huge disservice again to the communities around our coasts. If there is a silver lining for fishermen it will be in easements for trade and stability for key export markets – but that is still far from the ‘sea of opportunity’ that was promised in the past. The APPG will be scrutinising the details and will continue to work in support of a viable future fishing industry.”

APPG Co-Chair Melanie Onn MP said, “The impact of Brexit has been significant for the UK’s fishing and seafood sectors – affecting fleets and also trade with the EU, our largest trading partner. I've seen this first hand in my own constituency of Great Grimsby and Cleethorpes, where around 6000 livelihoods are supported by processing. We welcome the improved opportunities for trade with the EU that the SPS deal announced today will enable by making it easier for producers to sell British fish to our largest trading partner.

"While sadly weighed against other objectives time and again, the fishing and seafood sectors are vitally important all around the coast of this nation, providing livelihoods, sustaining families and communities. In the face of this, since 2020 the sector has continued to work to provide nutritious food to markets. With full details, the APPG will be meeting tomorrow to discuss an updated plan of work to support the continued efforts of the catching, processing and related sectors in this, and to safeguard the future for the UK’s fleets, seafood businesses, and coastal communities."