Seafood Hazards - supporting safe and sustainable seafood newsletter

Serious diseases pose a threat to aquatic animal health both in aquaculture and in the wild. Many of these diseases have no effective treatment and have the potential to cause high numbers of mortalities in aquatic animals, with the consequent large economic loss and threat to biodiversity and food security. 

The UK has a high aquatic animal health status, being free of most of the serious diseases of fish and shellfish that are subject to control. The FHI at Cefas is the regulatory body responsible for the official control of these diseases in England and Wales and work hard to maintain this high health status, protecting fish stocks and industry. Their work is delivered on behalf of Defra and Welsh Government to ensure a sustainable aquaculture industry that meets international standards and ensures safe trade.

Find out more about the breadth and depth of their varied work in our recent Fish Health Inspectorate blog.

Southern Water have recently been fined a record £90m for deliberately pouring sewage into sea. The case saw 6,971 unpermitted sewage discharges taking place in Kent, Hampshire and Sussex between 2010 and 2015. Cefas was called upon to provide scientific support for the Environment Agency’s prosecution case relating to Southern Water causing major environmental harm to shellfish waters. Our blog describes how Cefas' evidence supported the successful prosecution, drawing on our decades of microbiological water quality research. Cefas’ involvement in this case is a tangible example of how our research makes a real difference to supporting production of safe seafood.

One more unusual aspect of Cefas’ food safety work is our involvement in seafood-borne human illness investigations. In the UK, an estimated 12,000-14,000 people per year experience sickness and diarrhoea after eating seafood, usually raw oysters. 

Frequently shellfish-borne illness is caused by the group of viruses known as noroviruses. Norovirus is an extremely common infection with an estimated 3 million cases per year in the UK, mostly (~84%) transmitted via person-to-person contact, but oysters, exposed to noroviruses when human sewage enters their growing areas, can be vehicles of disease. It is estimated that over 13 million oyster meals are served in the UK annually, many of them consumed raw, so whilst the odds of contracting norovirus from eating raw oysters are relatively low, anyone who has ever suffered with the virus will know just how unpleasant it is. 

The annual Invasive Species Week took place between the 24th and 30th May 2021, led by the GB Non-Native Species Secretariat (NNSS) with many organisations taking the opportunity to raise awareness of the issues and what work is being done to address invasive non-native species (NNS).

Globally, aquatic ecosystems are being increasingly threatened by invasive non-native species, which are moved from their native habitats to novel ecosystems by human activities. Invasive species can cause major negative impacts on the environment, human health, food security and the economy,

Non-Native Species (NNS) work at Cefas spans our science themes, but the threat to native seafood species such as lobsters and oysters is one key element. You can find out more in this Twitter Moment and in our blog.