Growth and reproductive simulation of candidate shellfish species at fish cages in the Southern Mediterranean: Dynamic Energy Budget (DEB) modelling for integrated multi-trophic aquaculture

A Dynamic Energy Budget (DEB) model is used to simulate growth and reproduction of the shellfish Mytilus galloprovincialis and Crassostrea gigas in an integrated multi-trophic aquaculture (IMTA) farm scenario situated in the Southern Mediterranean (the Gulf of Castellammare, Sicily). We modelled the effect of primary production enrichment at fish cages on shellfish growth and life history traits using 4 years-hourly temperature data (01 January 2006–31 December 2009) at a depth of 1 m. Outputs of the DEB simulations were: the maximum theoretical total shell length of shellfish, the potential reproductive outputs and the mean annual von Bertalanffy growth rate. There was a mean increase in empirically measured suspended chlorophyll-a of approximately 45% close (within about 100 m) to fish cages (2.3 ± 1.1 μg l− 1) compared to sites away (about 1.5 km) from the cages (1.3 ± 0.6 μg l− 1). DEB simulations using localised CHL-a measures showed that mussels close to cages could reach greater maximum length at the end of 4th year than those far from cages and in open-sea. Simulations of oyster growth close to cage sites resulted in double growth rate (12 cm in 4 years) compared to oysters at far sites (6.5 cm in 4 years). The present study improves knowledge of the application of DEB models to predict the potential fitness of shellfish starting from First Principles. This is an innovative approach with potential for application at larger scales than those of local facilities.

► Growth and reproduction of shellfish species in an IMTA scenario were simulated.
► Empirical measures of Chlorophyll-a were higher closer to fish cages.
► These measures were included in the Dynamic Energy Budget (DEB) model.
► Shellfish close to fish cages reached a greater length than those far from cages.
► DEB models can predict the fitness of IMTA shellfish from First Principles.