SALMON numbers of a Dorset river have been falling for a number of years, with a recent report stating that the decline shows no sign of slowing.

Leading conservation science charity the Game & Wildlife Conservation Trust (GWCT) carries out all its research into salmon on the River Frome in Dorset. GWCT's latest Fisheries Research Review showed that a disappointingly low number of adult fish returned to the river last year.

It was hoped that a good number of smolts (young salmon leaving the river for their marine journey) in 2018 would boost these numbers, but the report revealed that far fewer returned to the river than expected.

The reasons given for this poor return was the "worrying low" number of smolts leaving the river and their small average size.

To understand the declines, fishery ecologists at East Stoke, near Wareham, have been monitoring smolts on the River Frome 24 hours a day for six weeks. April and May were spent netting sea trout at sea and in May, June and July the team worked on three rivers to recapture sea trout previously fitted with data storage tags. August and September were spent on the River Frome, catching and tagging 13,000 trout and salmon parr (an early development stage of salmon).

Despite the impact of Covid-19 in 2020, the fisheries team enlisted their families to ensure that Dorset’s River Frome was perhaps the only river in Britain to have full monitoring through lockdown. This dedication has avoided a two-year gap in the data, as this year’s smolt will be monitored when they return as adults over the next two years.

Much of this work is part of SAMARCH, a multi-million-pound project that will provide crucial evidence to strengthen the management and protection of salmon and sea trout at sea over five years (2017 to 2022).

Finding the positives in a challenging year, David Mayhew, chairman of GWCT fisheries research steering committee, said: “Our fisheries team spent more time in the field last year than probably any other year in the last 10 years. Furthermore, two of our PhD students, Jessica Marsh and Jessica Picken, submitted their theses on the importance of instream vegetation for salmonids and the effect of low flows on salmonid ecosystems, respectively. A remarkable achievement.”

The review can be downloaded for free at www.gwct.org.uk/fisheriesreport.

For more information, visit www.gwct.org.uk/fishing/