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Crimes Against Freshwater Pearl Mussels


What are crimes involving fresh water pearl mussels?

Freshwater pearl mussel - pearlsAs their name suggests, freshwater pearl mussels will very occasionally bear a pearl. In some ways this may have led to their downfall, with over-exploitation by 'pearl-fishers' primarily responsible for the massive declines observed in their numbers and range. But as filter feeders living on the river bed they are also extremely vulnerable to water pollution, river engineering works (such as construction of weirs and deepening of pools), or extraction of sand and gravel from river beds.

Pearl fishing is often carried out when rivers are low in the spring and summer and early in the morning or in remote locations to avoid detection. Fishing is often carried out by wading into the river, using a glass-bottomed bucket to find the mussels and a cleft stick to retrieve them. Mussels are killed as they are prised open and often discarded in piles on the river bank.

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Why do they matter?

Freshwater pearl mussels are on the brink of extinction. Scotland's rivers are a global stronghold for the species, containing around half of the world's population.

They used to be found across Europe and the UK but are now restricted to a few small populations in Southern Scotland and some more abundant populations further North.

Conservation work by SNH and other organisations is taking place to improve habitats for mussels, to tackle pollution and reintroduce animals to rivers where they have become extinct. However, criminal activity threatens to undermine this work - just a few hours pearl-fishing, or someone undertaking engineering works illegally, can wipe out whole populations of these animals in one fell swoop.

Freshwater pearl mussels are a fascinating species. They grow much larger than their marine relatives and can live to over 100 years old. They are dark brown to black and live in the bottom of fast-flowing streams and rivers where they may be completely or partially covered in sand or gravel. Freshwater pearl mussels feed by filtering food particles out of the river water - adults can filter up to 50 litres of water a day. They also have a very unusual lifecycle - their first year of life is spent harmlessly attached to the gills of young salmon or trout before they drop off to settle on the river bed.

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What does the law say?

  • It is an offence to intentionally or recklessly kill, injure, take or disturb freshwater pearl mussels or to damage their habitat.
  • It is also illegal to possess mussels or pearls collected since 1998 (when the law was changed to give them further protection)
  • It is illegal to sell, or advertise for sale, freshwater pearl mussels or their pearls unless done under licence from the Scottish Government.

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What can I do?

Despite the protection afforded to freshwater pearl mussels, illegal activities continue, and as a result the pressure on our remaining populations increases. Whilst the police and other organisations do their best to try to tackle these crimes and conserve the species, your help is absolutely crucial!

If you; Freshwater pearl mussel - shells

  • see any suspected pearl fishing or suspicious activities in or around rivers ; or,
  • see any evidence that pearl fishing may have taken place (such as piles of shells on a river bank); or,
  • suspect that river engineering works may be damaging or destroying the river bed where pearl mussels are found; or
  • have any information that someone is involved with pearl fishing or any criminal activity that could affect this species;

you should report it to the police as soon as possible.

Most police stations will have a 'Wildlife Crime Officer', but if he or she is not present then it should be reported to the police officer on duty at the time.

If you are planning river engineering works, then as well as requiring authorisation from the Scottish Environment Protection Agency (SEPA) and possibly planning permission, you should ensure that your plans will not affect freshwater pearl mussels. SEPA and SNH will be able to help you with your plans to ensure that they take account of freshwater pearl mussels. Failure to do so may mean that you are breaking the law.

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