CORNISH fishermen are warning that a boom in octopus numbers in local waters could spell serious trouble for the future of shellfish fishing, with young Looe skipper Will Jaycock among those most concerned about what lies ahead if the surge continues.

Will – a third-generation fisherman from the Cornish port, whose heart is set on a sustainable future for fishing – said the 2025 season began positively, with strong lobster catches in late winter and early spring.

“Everything was going alright,” he said. “There were lots of lobsters early in the year and it felt like it was shaping up to be a good season.”

That optimism quickly faded as octopus began appearing in unprecedented numbers. “At first it was one or two and you don’t think much of it,” he explained. “Then in the space of three or four weeks we were hauling 100 or 200 kilos a time. From there it just went mental!”

One boat in Looe landed 1.2 tonnes of octopus in a single day, a sign of the scale of a bloom that scientists now say is the most impactful seen in years.

A recent study links the surge to unusually warm sea temperatures driven by climate change, with ocean currents carrying octopus larvae into South West waters.

Dr Bryce Stewart, senior research fellow from the Marine Biological Association, said: “If these conditions persist, octopus blooms could become a more regular feature of our changing seas. Understanding their causes and consequences is vital to help both ecosystems and coastal communities adapt.”

But while the sudden abundance brought short-term financial relief, Will fears the long-term cost could be devastating.

“They don’t discriminate,” he said. “They were killing small lobsters, berried lobsters, v-notched lobsters – the ones we protect to keep things sustainable. I’m very concerned as to what they’ve done to the stocks because the damage inside the pots was bad.”

Surveys show crab, lobster and scallop catches dropped by between 30 and 50 per cent in 2025, and Will worries the real impact is yet to be felt. “It takes nine years for a lobster to reach landing size and only one or two per cent survive naturally,” he said. “If the octopus have hammered the breeding stock, we won’t know the full damage for years.”

The Marine Management Organisation recorded more than 400 tonnes of octopus landed in May 2025 alone, compared with pre-2025 monthly figures that rarely exceeded 75 tonnes. Although octopus fetched strong prices and export demand was high, Will said money now will not matter if shellfish stocks collapse.

“It was the best year any of us have ever had,” Will admitted, with octopus fetching around £6.50 a kilo and strong export demand to Europe. “That’s what saved us.”

However, the long-term outlook worries him. “I’ve invested heavily back into the business – refits, new gear – and I’ve still got a big loan to pay,” he said. “Another year of octopus money might help short-term, but if there’s no shellfish left, it doesn’t matter. There won’t be a future.”