The potential of shoreface nourishments for habitat enhancement: a case of the sand engine lagoon as a nursery for juvenile plaice Pleuronectes platessa L.

Sand nourishments are implemented to protect the shallow coast of the Netherlands. A mega nourishment pi lot project was started in 2011 that will nourish the coast for the coming 20 to 40 years. The Sand Engine is a manmade peninsula with an artificial lagoon. This lagoon was created to serve as a nursery area for juvenile plaice, Pleuronectes platessa L. . The numbers and growth of 0 group plaice in the lagoon and the coastal areas in 2012 and 2013 were compared to assess the possibility of nursery enhancement. The present study revealed that the lagoon had an increased attraction on 0 group plaice in 2012, with substantially higher numbers than the adjacent shallow coastal area. Changes in the lagoon dynamics and shape resulted in the loss of this nursery potential in 2013. In this year the lagoon did not harbour better growth conditions than the adjacent shallow coastal area. The objective of habitat enhancement for the lagoon of the Sand Engine worked only temporarily. A Dynamic Energy Budget model indicated that growth was not optimal during the whole growth season, suggesting that food might be a limiting factor. The current design is thought to be inappropriate for long term nursery creation due to the small nursery area and limited food supply. The acquired knowledge can be applied in future nourishment designs aimed to enhance the nursery value of the coastal zone.