Simulation of mussel Mytilus galloprovincialis growth with a dynamic energy budget model in Maliakos and Thermaikos Gulfs (Eastern Mediterranean)

Abstract

A dynamic energy budget (DEB) model was developed to investigate the growth and reproduction of cultured bivalve species raised under different environmental conditions (varying phytoplankton carbon biomass [Phyto-C], particulate organic carbon [POC] and temperature) and tuned against field data for Mytilus galloprovincialis from the Maliakos and Thermaikos Gulfs (Aegean Sea, Greece). Values of most DEB model parameters were adopted from the literature, while half saturation constant (Xk) and initial values of energy reserves (E) and reproductive buffer (R) were calibrated. Different values have been found for Xk in the 2 areas (Maliakos: Xk = 36 mg C m-3; Thermaikos: Xk = 28 mg C m-3), suggesting that Xk should be treated as a site-specific parameter. Food density (X) was adapted to include not only Phyto-C but also POC in the diet of M. galloprovincialis and only when Phyto-C density was low compared to POC density. Results showed a small contribution of POC during spring in the Maliakos Gulf and almost none at Thermaikos Gulf. The simulated mussel growth showed good agreement with field data. Sensitivity tests on the calibrated parameters (E, R and Xk) were performed to investigate model uncertainty. The standard deviation of simulations with perturbed parameter/initial values remained relatively small and appeared to increase as the modeled mussel grew, in agreement with observations.