Weever stings provide scientists with a unique way of assessing impacts of environment on coastal fish populations
Lloyd Russell
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 time and space, in relation to environmental conditions.
The study, by marine scientists at the University of Plymouth 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 (e.g. bathers, surfers) on beaches.
They also record the number of people requiring assistance after being stung by weever fish, and analysing that – along with environmental data – provided scientists with a unique window into how environmental conditions affect fish populations.
They 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. Stings tended to occur most often around the times of low tide.
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.
Published in the journal Estuarine, Coastal and Shelf Science, the research was led by former masters student Mr Ryan Hepburn and Lecturer in Marine Biology Dr Benjamin Ciotti from the University’s School of Biological and Marine Sciences.

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. 

Benjamin CiottiDr Benjamin Ciotti
Lecturer in Marine Biology

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. 
Dr Sam Prodger
Head of Data at the RNLI 
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.
Weever stings provide scientists with a unique way of assessing impacts of environment on coastal fish populations
Weever stings provide scientists with a unique way of assessing impacts of environment on coastal fish populations
Weever stings provide scientists with a unique way of assessing impacts of environment on coastal fish populations
  • The full study - Hepburn, Scott, Prodger and Ciotti: Drivers of variability in surf zone habitat use by sandy beach fish: Unwitting citizen scientists reveal detailed spatiotemporal patterns - is published in Estuarine, Coastal and Shelf Science, DOI: 10.1016/j.ecss.2024.108957.