Mussels decliningon the Fenham Flats
A survey of the mussel beds at Fenham Flats, part of the Lindisfarne National Nature Reserve, suggests the population is in decline.
The report has been published by the Northumberland Inshore Fisheries and Conservation Authority, which undertakes an annual survey on the mudflats.
Report author Natalie Wallace said: “The mussel bed on Fenham Flats covers an area of 42.9 ha with a percentage cover of 58.61%.
“The estimated values obtained for density and total number of mussels are the lowest recorded to date suggesting the mussel population at Fenham Flats is in decline.
“The current values of 58 million mussels and 145.9 mussels per m² are the lowest value obtained since the survey began in 2006.”
Total biomass has also declined (estimated 1928 tonnes), with the majority of the biomass composed of the larger (and therefore heavier) mussel size class.
Mean length of mussels sampled was 55.5mm in 2017 and has increased each year since 2008.
Threats to mussel beds include bait collection, gathering for human consumption, pollution, coastal development and anchoring.
It is currently unknown whether mussel beds are declining because of these threats, due to bird predation or a combination of factors.