Numbers of adult salmon that returned to the River Frome in 2018 were at a worrying low, according to the latest figures in a fisheries report.

The 2018 Fisheries Research Review, published by the Game & Wildlife Conservation Trust (GWCT), shows that the very low number of smolts left the River Frome in 2017 resulted in a poor run of one-sea-winter (grilse) fish returning to the river last year.

The knock-on effect of the poor recruitment from the spawning in the winter of 2015/16 is that young recruitment in 2019 and 2020 will be compromised.

David Mayhew, chairman of GWCT fisheries research steering committee, said: “A better understanding is urgently needed to protect this enigmatic species from bycatch in coastal nets and to preserve coastal areas of special importance to sea trout.”

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This result was predicted by the freshwater ecologists in the GWCT fisheries team, who are based at East Stoke, near Wareham.

Poor recruitment from the 2015/16 spawning season was reported widely across much of England and Wales. Other rivers affected by this poor spawning season are likely to see the same effect on the number of returning adults in 2019 and 2020 as smolts from the River Frome and other chalk streams are generally a year younger than smolts from other rivers.

Research shows that larger salmon smolts survive better at sea than smaller smolts. It appears that a 16cm smolt is three to four times more likely to survive their marine migration compared with a 12cm smolt.

The fisheries team have had a hugely-successful year tagging sea trout as 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).

The fisheries team have now started their annual tagging of 10,000 salmon and 3,000 trout parr to track their movements and life-history choices.

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