Investigators probe mystery of Norfolk's vanishing mussels

But there are concerns the mussel beds around the Wash and north Norfolk coast, from which the succulent shellfish has been harvested for centuries, are in decline.

Mussels are a Norfolk speciality (Image: Simon Finlay)

Experts have warned about the long-term prospects for the mollusc, both in terms of numbers and size, prompting an investigation by Natural England.

The reason for the aquatic animal's decline has so far stumped researchers and fishermen.

Among the theories suggested are that mussel beds may be silting up, that they are suffering the effects of pollution or warming seas, driven by climate change, or that harmful pathogens may be responsible.

Mussel beds (Image: English Nature)

Natural England, the government advisor, has commissioned research to find out which, if any, of these are behind the decline, or if it is a combination of them.

A spokesman said: "Mussel beds in the Wash have been in general decline for a number of years. This review will investigate why, and explore what can be done to reverse it.

"The beds are hugely valuable for the habitat that they provide, and as part of the wider food chain. They also have an economic importance to the local fishery.

"This research will look at whether and how it has been managed and reversed elsewhere, to learn more about what may be possible for the Wash."

Natural England is concerned at the long-term decline of mussel beds in The Wash (Image: English Nature) READ MORE: Natural England objects to Norwich Western Link scheme over harm to bats

The investigation follows separate monitoring by the Eastern Inshore Fisheries Conservation Authority (IFCA), which regulates the mussel fishery , which found "unusually high levels" of mortality on mussel beds in the Wash since 2009.

Just to cloud the waters, however, the IFCA has reported a bumper bivalve crop for the last two years, with the total haul going up from 20,597 tonnes to 23,410 tonnes - the highest since 1945.

But the IFCA has cautioned this could just be a blip, adding: "There is concern that these two years might just be an anomaly, preceding further die-offs and another crash.

"If a pathogen is involved, it is unlikely that the mussel stocks will have become immune to its effects so suddenly, suggesting other environmental factors are also having an influence.

"While these may have created suitable conditions for mussel survival over the past two years, they  could easily change again, resulting in further losses."

Thomas Large, of Brancaster Bay Shellfish (Image: Instagram/Brancaster Bay Shellfish)

Thomas Large runs Brancaster Bay Shellfish and is the latest of several generations of his family who harvest mussels.

He said the last two years had been encouraging but welcomed the research to protect the future of the industry.

"Mussels have bounced back in the past couple of years and it has improved beyond belief," he said.

"I do fish the beds in the Wash and we've been seeing mussels on beds which haven't had them on in 30 years.

"And it's not just the numbers, it's the quality of them which has got better.

"It is encouraging, but they are still vulnerable and we need to take care of them."

The White Horse pub in Brancaster hosts an annual festival of mussels (Image: The White Horse)

With rising concerns over the mussels from the Wash and Brancaster, which hosts an annual mussels festival, an example further down the coast demonstrates the fragility of the bivalve.

The Morston mussel industry was devastated a decade ago, because increasing levels of sand and silt meant fishermen were no longer able to plant mussel seeds and cultivate them.

FROM STAPLE TO DELICACY

The Common or blue mussel (Mytilus edulis) lives on rocky, sandy or muddy shores.

The bivavle mollusc forms dense mussel beds which cover the seabed.

They are attached to rocks by strong fibres called byssal threads (and sometimes known as the beard), which are secreted by glands in the foot of the mussel. 

They eat detritus and plankton, which they filter from the water.

Despite being known as blue mussels, because of the colour of their shells, they are sometimes purple or brown.

They have been a staple of coastal communities for centuries and were once referred to as the 'poor man's shellfish'.

But they have become a more exclusive delicacy in recent generations.

Traditionally, it is said you only eat mussels when there is an r in the month - from September to April.

That is the time when mussels are in season and supply is at its greatest, but also because algae bloom in the summer months can poison them.

RECIPE: MUSSEL LINGUINE

Prep time: 5 minutes
Cooking time: 13-15 minutes
Serves: 4

INGREDIENTS
1kg fresh, live mussels
2 tbsp butter
2 tbsp olive oil
1 large onion, finely chopped
4 garlic cloves, finely chopped
175ml white wine
1/2 tsp dried thyme
400g linguine
Handful of chopped parsley, to garnish

METHOD
Prepare the mussels: check all the mussels are closed and discard any that are open or don’t close with a gentle tap, together with any that are cracked or damaged.

Pull off the beard and scrub with a stiff brush under cold running water to
remove any barnacles.

Melt the butter with the olive oil in a saucepan over a medium-low heat.

Add the onion and garlic and cook for 3 minutes or until the onion is almost translucent.

Pour in the wine and thyme and stir, then add the mussels. Stir and cover the pot for about 8-10 minutes.

While the mussels are cooking, cook the linguine according to the instructions on the pack and drain.
Discard any unopened mussels, season with salt and pepper and stir through the linguine.

Garnish with the parsley and serve with a baguette.

Source: www.seafish.org