![]() In 2016, restoration pilots started in a near shore area ( Sas et al., 2016: 2018 Didderen et al., 2019a: Van den Brink et al., 2020), which was followed in 2018 by pilots further offshore ( Didderen et al., 2018: 2019b: 2019c: 2020). Efforts to restore the species and its habitat in the Dutch North Sea started in 2014 with a number of feasibility studies ( Smaal et al., 2015: 2017 Kamermans et al., 2018a: 2018b). Several flat oyster restoration projects are currently being carried out in Europe ( Pogoda et al., 2019). At present, only a few individuals remain in the North Sea ( Kerckhof et al., 2018). Currently, the species is listed as ‘threatened’ or ‘declining’ by the Convention for the Protection of the Marine Environment of the North-East Atlantic (OSPAR) ( Haelters and Kerckhof, 2009). However, intensive flat oyster fishery at the end of the 19th century caused the oyster population to decline rapidly ( Gercken and Schmidt, 2014 Houziaux, 2008). was a common species in the North Sea until about a century ago ( Gercken and Schmidt, 2014 Houziaux et al., 2008 Olsen, 1883). The restoration of habitat-forming species is being applied throughout the world's oceans to halt the loss of biodiversity, combat climate change and help sustain the provision of ecosystem services such as nutrient cycling or eutrophication control ( Saunders et al., 2020). ![]() This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( ), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The results show that hatchery production of Bonamia-free and potentially Bonamia-tolerant flat oysters is possible. Further challenge tests are needed before firm conclusions regarding the genetic markers can be made. However, mortality of the naïve group could not be related to Bonamia presence. A higher percentage of individuals with tolerance-associated marker genotypes was found in the screened group compared to the naïve one. Samples of seed were analysed for association of candidate genetic markers related to bonamiosis tolerance. Survival of the pre-selected Bonamia-free oysters was significantly higher than the naïve group. To study if the Delta area oysters had developed a degree of resistance to the disease, while the naïve Wadden Sea oysters had not, seed of both groups was challenged in Lake Grevelingen where Bonamia occurs. These oysters also produced Bonamia-free larvae and seed. For comparison, broodstock oysters were collected in the Dutch Wadden Sea, an area free of Bonamia. These oysters produced Bonamia-free larvae and seed. With the aid of a non-destructive screening method, Bonamia-free broodstock were selected. In addition, the oysters were analysed to identify candidate genomic regions related to bonamiosis tolerance and exposed to Bonamia in the field to assess survival compared to a naïve control group. The aim of this research was to obtain Bonamia-free seed from parents collected in a Bonamia-infected area. ![]() Adult oysters were collected in the Dutch Delta area which is infected with the pathogenic parasite Bonamia ostreae. edulis is functionally extinct it is advised to treat these as disease-free areas. When flat oyster beds are restored in areas where O. Flat oyster restoration is taking place at a number of locations in the North Sea. Native (flat) oyster ( Ostrea edulis) beds, once a major component of the North Sea, largely disappeared from the region in the late 19th century. Stichting Zeeschelp, OosthavendBK Kamperland, The Netherlandsĭepartment of Zoology, Genetics and Physical Anthropology, Faculty of Veterinary, University of Santiago de Compostela, 27002 Lugo, Spain ![]() Box 364, 4380 AJ Vlissingen, The Netherlands Royal Netherlands Institute of Sea Research, Texel, The NetherlandsĪquaculture in Delta Areas, University of Applied Sciences, P.O. Hatchery Roem van Yerseke, Groeninx van ZoelenstrKZ Yerseke, The Netherlands Marine Animal Ecology Group, Department of Animal Sciences, Wageningen University, PO Box 226, 6700 AE Wageningen, The Netherlands Sambade 8, Manuel Vera 8 and Paulino Martinez 8 Pauline Kamermans 1 ,2 *, Ainhoa Blanco 1, Pim van Dalen 1, Marc Engelsma 3, Nienke Bakker 4, Pascalle Jacobs 5 ,6, Marco Dubbeldam 7, Inés M.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |