Native Oyster Restoration in the Adriatic Sea

Photo: IOR, Split


Potential and Perspective of Native Oyster Restoration in the Adriatic Sea

Funding body: Croatian Science Foundation

Today, over 90% of oyster reefs are considered to have disappeared in some areas. In the European ecoregion, the status of oyster reefs is described as poor or even functionally extinct. In the case of European flat oyster Ostrea edulis, decline is a result of the synergistic effect of the high mortality rate observed in O. edulis due to overfishing and a parasitic disease caused by the parasite Bonamia ostreae. Since oysters form biogenic reefs and play an important ecological role in the ecosystem functioning, in the last two decades, significant efforts have been made to restore the native oyster populations and their habitats.

Although, O. edulis vanished entirely in some areas, it is still present in the northern Adriatic. However, recent data also showed that O. edulis abundance in the northern Adriatic decreased significantly during the last decade. Despite having the advantage over other regions, as O. edulis is still present in natural populations, there is a lack of research on this species in the eastern Adriatic. While most of the research focuses on the farmed oyster population.

POPOyster project will serve as a first holistic action in the Adriatic Sea aimed to identify new and relevant biological and ecological data about natural populations of O. edulis necessary for future conservation and restoration measures. POPOyster is a highly multidisciplinary project that includes basic biological research, ecological experiments, molecular biology, fisheries, physical oceanography, ecological modelling, and material science. Therefore, POPOyster can be considered a first step toward restoring natural oyster populations in the eastern Adriatic.

This will be achieved by: 

  1. analysing the current status of oyster beds in the northern Adriatic;
  2. analysing biological and ecological traits such as reproduction and feeding ecology of O. edulis from natural population and related environmental parameters;
  3. analysing the food web structure and trophic interactions of O. edulis;
  4. improve knowledge about suitable substrates for oyster settlement.

Photos: Survey of natural oyster beds in the North Adriatic Sea region. Copyright: IOR, Split

POPOyster results will serve as strong scientific baseline for protection, conservation and restoration measures for the policymakers in Croatia.

Project PI and contact person:

Dr Daria Ezgeta-Balić

Institute of oceanography and fisheries
Šetalište I. Meštrovića 63
21000 Split, Croatia

Project website: