Protocol for seasonal vitality of mussels when treated with fresh water to reduce starfish predation
Mussels are cultured on a large scale culture in The Netherlands, the sector involves about 80 companies and cultivation is carried out on about 100 km2 of culture plots in the Oosterschelde and Dutch Wadden Sea. The main predation on mussels is by Starfish. They can cause substantial losses on mussel culture plots. Mussel farmers apply several measures to reduce starfish predation. Starfish are removed from the culture plot by fishing mussels with starfish into the hold of the vessel, and one of the most used methods to get rid of the starfish is to fill the hold, containing both mussels and starfish, with fresh water. Mussels can withstand this treatment by closing their valves, while starfish will die from the osmotic stress. However, survival of the mussels can also be affected by this treatment depending on a combination of factors: mussel condition, seasonal influence of spawning, or mechanical stress due to fishing and pressure in the hold of the vessel.
We want to know more about the vitality of the different mussel sizes over the year and want to know what the impact of the freshwater treatment on this vitality does. The challenge is to find the optimal duration of this treatment, given the factors that affect this, by which the mussels will not suffer extra mortality and the starfish will not be active anymore. Building on previous experiment, we want to develop a protocol by which mussel condition and starfish condition will be examined, using a series of simulations that involves the aforementioned factors.
Research type: lab experiments (HZ, Vlissingen)
Research level: minor, internship (BSc. level)
Perquisite: preferably affinity with biology, lab work skills
Researcher involved: research group aquaculture (Eva Hartog/Tony van der Hiele)
Period: 2nd semester 2017-2018
Status: Open