Return of the native: Survival, growth and condition of European oysters reintroduced to German offshore waters


Contact
Verena.Merk [ at ] awi.de

Abstract

The European oyster (Ostrea edulis) is under significant threat across its natural distribution range and even functionally extinct in some regions, such as in the German North Sea. Due to its ecological significance in terms of biodiversity and other ecosystem services, the species, and the habitat it provides, are defined as highly endangered by the OSPAR Convention. Restoration measures are gaining momentum in Europe and conclusive recommendations for large‐scale biogenic reef restoration are relevant for example within the Marine Strategy Framework Directive and the Habitats Directive. This study examined whether present‐day environmental conditions of sublittoral offshore waters are ecologically suitable for the return of European oysters. Seed oysters (shell length ~2 mm) were deployed in cages in offshore field experiments in 10–26 m water depth. Survival, growth, and condition were investigated over the course of 2 years. Survival was high, even over winter. Growth was excellent, with oysters reaching a mean length of 55.0 ± 7.2 mm shell length and 19.2 ± 6.1 g wet weight after 2 years. The formation of firmly aggregated oysters was observed and confirms O. edulis as a reef‐building species. The overall condition of oysters in the field was excellent, identified by high condition indices and early reproductive activity. These findings are highly relevant for future restoration measures in the North Sea as they confirm that present‐day environmental conditions and small, hatchery‐produced seed oysters are suitable of supporting sustainable and successful restoration efforts even in sublittoral offshore waters.



Item Type
Article
Authors
Divisions
Primary Division
Programs
Primary Topic
Publication Status
Published
Eprint ID
53284
DOI 10.1002/aqc.3426

Cite as
Merk, V. , Colsoul, B. and Pogoda, B. (2020): Return of the native: Survival, growth and condition of European oysters reintroduced to German offshore waters , Aquatic Conservation-Marine and Freshwater Ecosystems, 30 (11), pp. 2180-2190 . doi: 10.1002/aqc.3426


Download
[thumbnail of Merk_etal_2020.pdf]
Preview
PDF
Merk_etal_2020.pdf

Download (12MB) | Preview

Share
Add to AnyAdd to TwitterAdd to FacebookAdd to LinkedinAdd to PinterestAdd to Email


Citation

Geographical region

Research Platforms

Campaigns
HE > 420-439 > 426
HE > 480-499 > 482
HE > 480-499 > 485
HE > 480-499 > 490
HE > 480-499 > 496/1
HE > 500-519 > 506


Actions
Edit Item Edit Item