Numerical models relating environmental variables, like food quantity and water temperature to shellfish growth can be helpful for optimization and management of shellfish culture sites, for spatial suitability analysis, and in understanding the dynamics of bivalve growth in an estuary or bay as a whole.

What does CoastObs offer?

CoastObs integrates spatio-temporal data of S3 basic products Chlorophyll-a, Total Suspended Matter and Sea Surface Temperature with the Dynamic Energy Budget theory for shellfish. Model output generally indicates for every pixel the growth potential in terms of shell length increase, but can be tailored to users wishes if desired (e.g. monthly maps or even daily if desired). Maps of shellfish culture potential are available for Blue mussels (Mytilus edulis) in the Dutch Wadden Sea and Oosterschelde estuary and the Mediterranean mussel (Mytilus provincialis) in the Spanish Galician Rias.

How was the data validated?

Goodness-of-fit was evaluated by linear regression between Dutch field observations of 2017 and 2018 (Mussel length) and the simulation mussel length output with S3 Chl-a, TSM and SST input. This model was then tested against the model Y=X at an α error threshold of 5%. Validation resulted in a linear correlation with overall R2 = 0.82.

Case study example: Dutch Wadden Sea and Galician Rias

Shell length (cm) at harvest in 2017 is shown below for the Galician Rias (left image), while shell growth rate (mm/day) in 2017 is displayed for the Dutch Wadden Sea (right image) indicating the variable output possibilities for this higher level product. Grey areas indicate land, shellfish cultivation areas are indicated with black squares or polygons.

Figure 1. Maps of shell length (left) and shell growth rate (right)