Growth of cockles (Cerastoderma edule) in the Oosterschelde described by a Dynamic Energy Budget model

• Published in: Journal of Sea Research
• Main Authors: Wijsman, J.W.M., Smaal, A.C.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2011
• Subjects: crassostrea-gigas; culture; estuary; individual-based models; marine; mussels; pacific oyster; shellfish; stock; sw netherlands; Pacific; Crassostrea gigas; Pacific oyster
• Online Access: https://research.wur.nl/en/publications/growth-of-cockles-cerastoderma-edule-in-the-oosterschelde-describ; https://doi.org/10.1016/j.seares.2011.09.007

A Dynamic Energy Budget (DEB) model for cockles is presented and calibrated using detailed data on cockle growth and water quality in the Oosterschelde. Cockles in the intertidal areas of the Oosterschelde have an important function as a food source for wading birds and as such for the natural values of the ecosystem. In the presented model, special attention is paid to the formulation and parameter estimation of the functional response. With this functional response, the food quantity and quality variables such as Chlorophyll-a, POM, POC and TPM are translated into food ingestion rate for the cockles. The calibration of the specific parameters included in this functional response is done using a detailed, long term dataset (1992–2007) of cockle growth in the Oosterschelde estuary. This dataset gives a good overview of the development of the cockle population in relation to the environmental conditions (food availability and ambient temperature). The DEB model was able to describe the spatial variation in cockle growth in the Oosterschelde as a function of environmental conditions and the parameters of the functional response. Both the data and the model show that growth performance of cockles is highest in the western and central part of the Oosterschelde due to the higher concentrations of Chlorophyll-a, which is an important food source for cockles. The model failed to describe the large variation in ash-free dry weight during the season. It is tested whether this is caused by aggregating the data by running the model for the full life cycle of year class 2001 at a specific location in the western part of the Oosterschelde. Finally, the model simulations have been compared to growth simulations obtained with an existing ecophysiological model for cockles in the Oosterschelde, the COCO model, with identical forcing. The COCO model showed higher growth in terms of shell length compared to the DEB model and the field observations