Cockle, cockles

Cerastoderma edule

Method of production — Caught at sea
Capture method — Hand-gathering
Capture area — North East Atlantic (FAO 27)
Stock area — Wales
Stock detail

Dee Estuary


Marine Stewardship Council (MSC)

Picture of Cockle, cockles

Sustainability rating two info

Sustainability overview

Choose cockles harvested by sustainable methods only such as licensed hand gathering. Avoid eating them during breeding season from March to July. Cockles from the Dee Estuary are MSC certified and are a sustainable choice. The fishery is currently closed.


The common cockle is a bivalve mollusc found buried in mud and sand in estuaries and on beaches. Cockles have distinctive rounded shells that are slightly heart shaped. It is a bivalve (two identical shells) belonging to the family Cardidae meaning ‘heart-shaped’ . An organ called a siphon allows the animal to feed and breathe whilst buried in the sand. They can jump by bending and straightening the foot - the end bit- which is often coloured red and called the ‘red nose’. The shell size is up to 5cm long, although average sizes tend to be around 3-4cm. Maturity occurs at a shell length of around 2cm. Cockles spawn from March to August, although exact times will vary from region to region.

Stock information

Stock Area


Stock information

Species widely distributed on coastlines throughout North Atlantic region. Cockle stocks are potentially vulnerable to local over-exploitation and depletion. Cockles breed from around Easter to end of summer.


Before the Cockle Regulating Order was made in 2008, the Dee estuary cockles had suffered from a series of boom and bust years. Over-harvesting when stocks were plentiful resulted in years when no cockles could be collected. Sustainable management of the fishery has resulted in the beds being opened every year since the Order came into force, stabilization of wide fluctuations in the cockle stock and provision of a stable income for professional cocklers. In 2012, 820 tonnes of cockles were harvested. The Dee Estuary cockle fishery is managed by Natural Resources Wales. The success of the fisheries management plan and its effective implementation has been recognised by the Marine Stewardship Council (MSC), which awarded the Dee cockle fishery MSC certification in 2012. It is only the second common cockle fishery in the world to receive this award. 53 full licences are issued each year, based on how many cockles can be sustainably harvested. Harvesting times are regulated and catches limited by quota restrictions. The cockle beds are open to fishing from July to December. Monitoring of the resource is also carried out. A so-called “cockle cam” with heat sensors, which can record images up to 3 miles away, is one of the methods used to regulate the beds harvest. Restrictions on harvesting aim to harvest one third of the resource. Leaving one third as breeding stock and the remaining third to wading birds such as oyster catchers. 300 kg per day are collected in the picking season. Illegal activity is a problem resulting in increased number of prosecutions in 2011. Members of the public can take up to 5kg of cockles a day for personal consumption if the cockle beds are open, but commercial harvesters must have a licence to gather cockles. Cockle fishery closed in May 2015. It is the first time the cockle beds will have to close since 2008. While the exact cause is unknown, it is likely to be due to a number of factors - including over-cropping last season, illegal cockling activities and natural causes.

Capture Information

Hand-gathering is a traditional method of harvesting molluscs involving the use of hand tools such as tongs and rakes. The cocklers beach their boats at low tide over the cockle beds to hand pick them. Riddles or seives are used to ensure cockles below the minumum landing size are not taken. Cockles small enough to pass through the mesh are left in place to rebury.