Eradication of oyster drill egg capsules
Since three years the Japanese oyster drill (Ocinebrellus inornatus) has become a big threat to oyster cultivation in the Oosterschelde and other systems in the South Western Delta of the Netherlands. The oyster drill is an invasive species that drills a hole in the shell of the oyster to feed on the flesh. The snail causes large oyster losses on the on bottom culture plots. They predate especially on smaller oysters thereby directly affecting the starting material for the culture. Since most of the oyster cultivation takes place on bottom plots, measures are needed to either keep the oyster drill outside the plots or to actively prevent drills to enter the plots. From February 2018 (depending on granted funds), the Delta Academy hopes to start a 2 year research project to help Oyster farmers deal with the Oyster drill on bottom plots and to decrease oyster mortality.
One way to deal with the oyster drill, is to keep it from expanding further on bottom plots. Previous research done in the United States show that oyster drills have extremely high fecundity, which means that even though juveniles have a low survival rate, this is compensated by large numbers of juvenile oyster drills. The reproduction cycle of oyster drills involves a male that fertilizes a female and the female attaches the egg capsules (each containing 8-10 larvae) to hard substrate, most often oysters.
Oyster farmers want to find a way to eradicate oyster drill egg capsules, after fishing the oysters from the bottom plot. For example by exposing oysters with egg capsules to warm water, acid, ultra sound or other treatments that can be performed on an oyster vessel. This will be performed by means of practical lab-experiments and additional literature research.
Research type: lab experiments and literature research
Research level: minor/internship
Perquisite: Technical skills, dedicated, creative, preferably affinity with biology.
Partners: Local shellfish famers, national and international knowledge partners
Researcher involved: research group aquaculture (Eva Hartog/Tony van der Hiele)
Period: 2nd semester 2017-2018
Status: open
