The Game & Wildlife Conservation Trust (GWCT) has monitored Atlantic salmon numbers in the River Frome, at our Salmon & Trout Research Centre since 1973. Creating one of the most comprehensive records of salmon movement in England and Wales. But the scientists based there have never seen this before….
At 6:13am, on the 24th January 2022 the camera attached to our resistivity counter on the flow gauging weir on the main stem of the River Frome at East Stoke, recorded a SEAL ascending the weir.
The unexpected visitor was spotted by SAMARCH Fisheries Ecologist, Luke Scott, whilst reviewing the video recordings from the camera attached to the salmon counter.
We use the resistivity fish counter to estimate the number of returning adult salmon passing East Stoke. It works by detecting the change in electrical resistance of the water caused by something more conductive passing over the counter.
As well as providing population data, the adult counter provides information on migration timing and the environmental factors that influence this.
The video attached to the counter, records images of whatever crosses the counter. This allows us to verify what triggered the events recorded by the fish counter, so that we only count actual salmon. The video recordings also enable us to estimate the length of returning adults.
You can imagine Luke’s surprise, as he studied the video recordings for salmon normally up to 30lbs, when he spotted the outline of a 200lbs seal.
Luke said “This is the first time we have ever seen a seal ascend the counter at East Stoke, and it’s incredible that we have captured it on the video. The fish counter is located 8km upstream of the tidal limit so he or she has travelled a long way, we can only assume in search of a food.”
Luke verified his discovery with colleague and Senior Fisheries Scientist William Beaumont. William, has worked in the fisheries group at East Stoke for over 40 years and this is the first time he has seen a seal ascending the weir.
So, what’s next? Will we see more visitors in the future? If we do, we will be sure to record them and let our members know.
To find out more about GWCT Fisheries Research visit: https://www.gwct.org.uk/fishing and read our Fisheries Reports which presents results from the research we undertake, including data collected by the fish counter: https://www.gwct.org.uk/fishing/research/fisheries-research-reports