Hand-harvesting wild Wadden Sea Oysters
Decolonisation of an invasive delicacy
Pacific oysters (Crassostrea gigas) are widespread in the tidal zones of the Wadden Sea National Park. Here over 12.000 tons of oysters have grown together to form small and large oyster reefs. Because this non-native species is not part of the original Wadden Sea ecosystem and do not have any predators, besides from man, they have spread rapidly impacting the natural balance of the maritime ecosystem by transforming the habitat and in places outcompeting the native blue mussel (Mytilus edulis) This can have an impact on those birds that primarily feed on mussels such as Common Eider, Oyster Catcher and European Herring Gull. The Pacific Oyster is believed to have spread from the introduction of oyster farming on the German Wadden Sea island of Sylt in 1986. As the temperature in the nourishment rich waters now yearly raises above the required 20 degrees centigrade necessary for the Pacific oyster to reproduce it has allowed the Oysters to spread wildly and uncontrollably.
At low tide the accessible reefs have become popular for excursion trips. In the whole Wadden Sea area from September to April various operators offer guided educational hikes in waders or wellies to the oyster reefs, were the public can harvest as many oysters as can be carried for own consumption. The Danish nature authorities encourage the Oyster Safaris, as this is the least harmful way of reducing the unwanted increasing masses of oysters in the Wadden Sea. It is also a good way of reconnecting the public to tidal zone foraging. The Wadden Sea Oysters have a delecious sweet briny taste with a creamy, herbaceous flavour with a hint of honeydew melon As it’s Latin name implies the Pacific Oyster can grow to a gigantic size and reach an age of around 30 years. In 2014 the worlds officially largest oyster was found in the Danish Wadden Sea. The huge oyster was 35 cm long and weighed over 2 kilogrammes. The record-breaking oyster shell is exhibited at Vadehavscenteret outside Ribe.