View article

In the last decades, the invasive Pacific oyster (Crassostrea gigas) increased dramatically in the Wadden Sea. One of the driving mechanisms for the success of the Pacific oyster could be a relatively low predation pressure by epibenthic predators and shore birds on oyster spat. Nevertheless, observations and experiments on predation rates on early life-stages of the Pacific oyster are rare. Therefore, we examined predation rates of brown shrimps on Pacific oyster spat in a number of laboratory experiments. Our results demonstrate that spat of Pacific oysters are most susceptible to predation by brown shrimps (Crangon crangon) in the first days after settlement, when attachment to the substrate (unglazed tiles in our study) is still absent or weak. At this stage the shell length of oyster spat is around ~ 300 μm, and around 50% of the individuals in the experiment were consumed in the two hour trials. Predation rates …