Nutrient cycling by mussel seed collectors

Summary

This thesis sheds a light on the implications for nutrient cycling of the juvenile mussel community
that forms on suspended substrates every summer as a result of the transition from wild capture
seed fishery to mussel seed collectors. Filtration and nutrient release rates by collector communities were quantified and combined into a nutrient budget, and the effects were observed in situ at the farm scale. These data were used to evaluate the ecological relevance of the nutrient cycling pathways via which the communities interact with their environment. It is concluded that the collector communities are able to exercise significant top-down and bottom-up control on phytoplankton at local, and potentially bay wide scale. In the Oosterschelde Bay this provides a substantial positive feedback to primary producers, which is particularly relevant for nitrogen given the shortage of this nutrient during the summer seed collection season.