Advice for anglers on the use of prawn bait

The use of uncooked prawns as bait for freshwater coarse fish could have detrimental effects on the environment. Recent articles in the angling press have promoted the use of uncooked prawns, such as ‘tiger prawns’ purchased from supermarkets. Cefas discourages this practise. Anglers using raw prawns as bait could introduce new diseases to our waters, with serious implications for native crustaceans. Most anglers understand and support the need for good bio-security. By doing so they are helping to protect the ecosystems that they hold so dear to their hobby, and assisting the regulators to protect the wider aquatic environment of the UK and mainland Europe.    

Tiger prawns (and other large ‘penaeid’ prawns) are imported products produced in seawater farms in tropical regions of the world. They have become significantly cheaper in Europe in recent years due to increased production/competition between producing nations and recognition of their culinary qualities. However, production regions in Asia and the Americas have been heavily impacted by a series of highly pathogenic diseases that have decimated the industry in some areas and have rapidly spread to previously ‘clean’ regions via poor husbandry practices. One of these diseases in particular, White Spot Disease (WSD) has caused perhaps the most significant problems with losses amounting to $10bn in the global industry since the late 1990’s.

WSD is also causing significant concern for aquatic managers in temperate areas of the world (such as Europe). Scientific studies have shown that the viruses causing WSD can survive freezing and can be transmitted (via feeding of raw infected ‘bait’) to temperate freshwater crustaceans such as crayfish and even to marine crabs (including the commercially significant European edible crab). Unusually for a virus, the WSD agent appears to be adaptable enough to infect a wide host range and may even impact upon smaller crustaceans (e.g. copepods) that form a key component of the aquatic food chain. Since the virus is extremely pathogenic and can kill its host within days, it is not surprising that some countries (such as Australia) are working very hard to keep this pathogen away from their waterways.

In addition to the threat posed by new diseases such as WSD, our native crayfish is already listed as an endangered species as a result of another disease, crayfish plague, introduced by an ‘alien’ species of crayfish (the American signal crayfish). The introduction of a new disease such as WSD to UK waters would impose a significant additional threat to the long-term future survival of this species in the UK.

Although no official legislation currently exists to prevent the practice of baiting with tropical prawns in fresh or marine waters, the new EU Aquatic Animal Health Directive (Council Directive 2006/88) due for application from August 2008 lists WSD and two other virus diseases of prawns – Taura Syndrome and Yellowhead, as ‘notifiable’ within the EU member states. Following this, action will need to be taken if these (currently exotic to the UK) diseases are detected in our waters.

Help keep our waters free of deadly diseases, stop using uncooked prawns as bait.

For further information contact:

Dr Grant D. Stentiford

Email: grant.stentiford@cefas.co.uk