Good news to end Covid-stricken 2020 was that, between March and May, the number of young salmon leaving Dorset’s river Frome at the beginning of their marine journey was the highest for eight years. Frome fish are some of the most closely monitored salmon in UK, and this spring more than 13,000 smolts passed through the Game & Wildlife Conservation Trust (GWCT) monitoring station, a 40% jump on the 10-year average for the river.
The Frome, like many rivers in UK, has recorded a worrying decline in stocks over recent years, which the experts at the GWCT believe might in part be caused by their size when leaving the river as smolts. A low return-rate in 2019 coincided with the smallest smolts ever recorded leaving the river in the previous year. It is hoped that the 2020 smolts, which were larger than average, will be robust enough to make it to sea and back in good health. Previous research by the GWCT has shown that larger smolts are more than three times more likely to return from the sea than smaller ones.
Rasmus Lauridsen, head of GWCT Fisheries Research, is encouraged by the findings: “It is more than ten years since we have observed this number of large smolts leave the river and given the relationship between return rate and smolt size I am hopeful that good numbers of adult salmon will return in 2021 and 2022”.
The detailed information GWCT scientists unearth provides information and an insight on the survival rates of salmon in the sea, so other rivers will be hoping their runs, which happened during the main period of UK’s lockdown, will have mirrored the Frome.
[First appeared as a ‘News Cast’ item in February 2021]