They’re the bane of Cornwall beachgoers every summer – and anyone who has stood on one will attest to the pain caused by those tiny spines hiding underneath the sand in the shallows.

Now a new study on weever fish has used lifeguard records of beach users and weever fish stings to learn more about their populations.

Weever fish are perhaps most commonly known for the painful stings they deliver to beach goers around the UK coastline.

However, a new study has used records of those stings to provide the one of the most detailed investigations of how fish populations vary, in relation to environmental conditions.

The study, run by marine scientists at the University of Plymouth and supported by the RNLI, focused on 77 beaches covered by RNLI lifeguards stretching from Burnham-on-Sea in Somerset, around the north and south coasts of Devon and Cornwall to Exmouth.

During daylight hours over the space of almost eight months, lifeguards compile two-hourly estimates of the number of people engaged in different activities, such as swimming and surfing, on beaches.

They also recorded the number of people needing help after being stung by weever fish.

Analysing that – along with environmental data – has now provided scientists with a unique window into how environmental conditions affect fish populations.

What were the results?

The data was recorded some six years ago and has been analysed since then, with the findings now published.

Scientists found that between April and November 2018, when the records were compiled, lifeguards observed a total of more than 5.5million people across the 77 beaches.

The study also showed that 89% of all stings occurred during the peak summer months of June, July and August, with smaller increases coinciding with the Easter and spring half term holidays. A sting tended to occur most often around the times of low tide.

Weever fish usually sting when their spines at stood on (Image: Getty Images) Overall, the scientists say, weevers seem to be more active in the shallows of beaches under the same conditions that humans prefer – sunny, calm summer afternoons at low tide.

With similar weever stings levels reported over a wide range of beaches, they also say there is evidence that weevers are suited to a wide range of beach environments and may be resilient to climate-related shifts in beach states.

How to treat and prevent a weaver fish sting

Weever fish sting when they are stood on and their spines release venom into a person's  foot. 

The best way to prevent  getting stung is to wear beach shoes with a hard sole, such a surf boots, jelly shoes or neoprene aqua shoes. 

But what do you do if you get stung? 

The first thing is find a source of hot water. This should be as hot as you can bear, but still comfortable enough to place your foot into it and leave it there. 

The heat from the water will help break down the toxins and reduce the spasms. 

If you can see spines left in the foot, remove them. 

It is recommended to leave the wound open and let it bleed if necessary, to release the venom with it. 

Pain, which is often compared to a bad jellyfish sting, is usually most severe for around 30 minutes before gradually subsiding, although some swelling may remain. Painkillers have help if you are particulary struggling. 

Published in the journal Estuarine, Coastal and Shelf Science, the research was led by former masters student Ryan Hepburn and lecturer in marine biology Dr Benjamin Ciotti, from the university’s School of Biological and Marine Sciences.

Dr Ciotti said: "Coastal waters are incredibly dynamic environments and the first in line to experience human impacts. Against that, it is hugely important to understand which habitats and conditions different species require, so we can manage our coast in ways that sustain healthy fish populations.

"Detailed information on how fish use our coasts, however, is just very hard to come by. We can spend all summer doing surveys just to get a few data points.

“Given the huge numbers of people who visit our beaches each year, the records compiled by the RNLI through the summer months are truly unique – I am not aware of any other dataset that provides such a detailed picture of habitat use in a fish species, anywhere.

"The positive in what can be a painful experience is that this is really helping us to understand what drives variation in fish populations inhabiting the shallowest waters which overlap most with humans."

A study of weever fish has been carried out by the University of Plymouth (Image: University of Plymouth) Dr Sam Prodger, head of data at the RNLI, added: "The RNLI was delighted to contribute to this research through guidance and utilising our extensive and unique datasets.

“It’s important for us to collaborate with partner organisations, including universities with their academic specialities, to enhance our understanding of the various hazards in the environments where we operate and to keep people safe.

“The outcomes from this work will help us understand the drivers behind one of the major time demands on our lifeguard service and examine the potential predictive factors for future years."

The study is part of wider efforts by the university, much of it funded through the UK Government’s Fisheries Industry Science Partnership (FISP), to monitor the health and habitats of fish species found around the UK coastline.

This includes the FinVision project, also led by Dr Ciotti, which is using specially developed underwater cameras to monitor the nursery habitats used by species including European sea bass and grey mullet.

Through the Pollack FISP and Ropes to Reefs FISP projects, researchers are also using acoustic tags and receivers to collect data about commercially important species and their interactions with Europe’s largest offshore mussel farm.