Development of strategies for the control of the pacific oysters in Danish waters (GIGAS) (39507)

The introduction of Pacific oysters to Danish waters was a consequence of aquaculture experiments carried in the 1970s. Following the establishment of wild populations, Pacific oyster populations have spread dramatically in recent years in a number of important areas for shellfish fishing—areas that are also of natural value—namely the Wadden Sea, the Limfjorden and the Isefjord.

The fishing industry considers Pacific oysters as a threat to their primary fisheries on blue mussels and flat European oysters. Governmental authorities consider the Pacific oyster as one of the potentially most harmful invasive species, threatening both shellfish fisheries and nature values, but action plans against invasive species state that public funds will not be invested in combating or mapping marine invasive species already established in Danish waters. It is therefore a wish of both industry and authorities to undertake actions that can be developed independent of public intervention programs.

The main objective of the project is the development of methods to prevent the spread of the invasive Pacific Oyster into areas where it may compete with blue mussel and flat European oyster populations. Such methods will preferably be based on commercially viable actions to be taken by the fishing industry, which will ensure the maintenance of the efforts without further public investment. Controlling Pacific oysters will protect natural habitats and biodiversity in Nature 2000 areas and the populations of species of commercial interested such as the flat European oyster, the blue mussel or the cockle.

The project is divided into a number of interrelated work packages. Integration of different approaches should result in proposals for a management practice that can provide space for fishing control of Pacific oysters with the aim of limiting their impact on nature, biodiversity and on other shellfish fisheries.

The work packages are:
WP 1: Mapping and stock assessment of Pacific oysters.
WP 2: Population dynamics and genetics
WP 3: Associated pathogens and other organisms.
WP 4: Development of pacific oyster fishing methods
WP 5: Communication and project management

The projects is coordinated by DTU Aqua and is funded by the European Maritime and Fisheries Fund and the Danish Fisheries Agency.

Research area: Shellfish and Seaweed