File yoldia likes silty bottoms

In the Voordelta, this involved finding sites in Brouwerhavense Gat east of Aardappelbult, according to field observers Jetze van Zwol, Jack Perdon and Jesse van der Pool who were involved in this sampling. At this location, the soil is silty, and that is the sediment type preferred by the file yoldia. They process large amounts of sediment while feeding. Research in its original habitat, the Northwest Atlantic, showed that even at low densities, this species can have a huge impact on the benthic ecosystem. They can easily turn the sediment completely upside down twice a year. This activity - called bioturbation - is in principle positive for the proper functioning of the ecosystem, as it contributes to better oxygenation and processing of organic material. However, bioturbation can also have a negative impact on other benthic animals. For example, it has been described for the Wadden Sea that common lugworms can have a negative effect on the densities of juveniles of other species, including cockles, through bioturbation.

Importance of long-term studies

Shellfish monitoring shows the importance of long-term studies of biodiversity and ecosystems. In the coastal zone, populations of many species have increased (razor shells, striped venus shells, otter schells) or recently recovered (cut through shells, banded wedge shells) during the last decade. The total biomass of shellfish is now much higher than at the beginning of the shellfish inventory. Johan Craeymeersch and his fellow researchers from the shellfish team at the Yerseke Regional Centre are interested in the cause of this apparent increase in the carrying capacity of large waters.

When does the file yoldia reach the Wadden Sea?