Applying Dynamic Energy Budget (DEB) theory to simulate growth and bio-energetics of blue mussels under low seston conditions

Abstract

A Dynamic Energy Budget (DEB) model for simulation of growth and bioenergetics of blue mussels (Mytilus edulis) has been tested in three low seston sites in southern Norway. The observations comprise four datasets from laboratory experiments (physiological and biometrical mussel data) and three datasets from in situ growth experiments (biometrical mussel data). Additional in situ data from commercial farms in southern Norway were used for estimation of biometrical relationships in the mussels. Three DEB parameters (shape coefficient, half saturation coefficient, and somatic maintenance rate coefficient) were estimated from experimental data, and the estimated parameters were complemented with parameter values from literature to establish a basic parameter set. Model simulations based on the basic parameter set and site specific environmental forcing matched fairly well with observations, but the model was not successful in simulating growth at the extreme low seston regimes in the laboratory experiments in which the long period of negative growth caused negative reproductive mass. Sensitivity analysis indicated that the model was moderately sensitive to changes in the parameter and initial conditions. The results show the robust properties of the DEB model as it manages to simulate mussel growth in several independent datasets from a common basic parameter set. However, the results also demonstrate limitations of Chl a as a food proxy for blue mussels and limitations of the DEB model to simulate long term starvation. Future work should aim at establishing better food proxies and improving the model formulations of the processes involved in food ingestion and assimilation. The current DEB model should also be elaborated to allow shrinking in the structural tissue in order to produce more realistic growth simulations during long periods of starvation.

Numerical modelling of spatio-temporal variability of growth of Mytilus edulis (L.) and influence of its cultivation on ecosystem functioning

“…We obtained δ = 0.257, and Figure 3 shows L plotted against DW. The value of δ obtained in this study is well within the range of 0.231 -0.333 reported in the literature (Rosland et al, 2009 andvan der Meer, 2006, respectively (J cm -3 d -1 ). Furthermore, we used TPM, POM, POC, PON, chlorophyll a and their combinations as food proxies and obtained the best fit when using chlorophyll a.…”

“…Chlorophyll a has been commonly used as a food proxy in previous DEB model implementations (e.g. Filgueira et al, 2011;Rosland, 2009;Thomas et al, 2011;van der Veer, 2006;van der Meer, 2006). Ren et al (2010) point out after Dame and Prins (1998) that phytoplankton is the main source of food and energy to support large populations of bivalves in coastal systems; these authors could not reproduce the growth when POC was included as the food source.…”

“…Since in addition to the somatic tissue, DW also includes the energy reserves and reproductive mass, the shape parameter was tuned in order to get 5% of the observed DW below the fitted curve, as the curve for structural tissue should lie below the observed masses. This approach was adopted after Rosland et al (2009). We obtained δ = 0.257, and Figure 3 shows L plotted against DW.…”

“…DEB models have been successfully applied to several shellfish species including Mytilus edulis (e.g. Handå et al, 2011;Filgueira et al, 2011;Maar et al, 2009;Rosland et al, 2009Rosland et al, , 2011Saraiva et al, 2011a;Thomas et al, 2011;van der Veer et al, 2006), Crassostrea gigas (e.g. Alunno-Bruscia et al, 2011;Barillé et al, 2011;Bernard et al, 2011;Bourlès et al, 2009;Emmery et al, 2011), and other species.…”

Numerical modelling of blue mussel (Mytilus edulis) bacterial contamination

“…Mytilus edulis, amongst other species, has been successfully modelled using a DEB approach (e.g. Dabrowski et al, 2013;Handå et al, 2011;Filgueira et al, 2011;Maar et al, 2009;Rosland et al, 2009Rosland et al, , 2011Saraiva et al, 2011;Thomas et al, 2011;van der Veer et al, 2006). Several authors have dynamically coupled DEB models with biogeochemical models to provide feedbacks from aquaculture farms to phytoplankton and nutrient dynamics (e.g.…”