The role of bivalves in the Balgzand: First steps on an integrated modelling approach

Abstract

a b s t r a c tThe present paper describes a process oriented modelling tool that integrates physical, biogeochemical, ecological and physiological factors governing bivalve populated marine ecosystems. This modelling tool is the result of the coupling between an individual-based population model for bivalves (based on the Dynamic Energy Budgets theory, DEB) and a hydrodynamic/biogeochemical model (MOHID Water Modelling System). The model was implemented in the Balgzand area (Wadden Sea, The Netherlands) in a fine resolution domain to study mussel population dynamics and to quantify the influence of mussel communities on the pelagic system. Model results for a reference scenario (2009/2010) are in agreement with observations, and provide a consistent quantitative description of local hydrodynamics and biogeochemical cycles. The Balgzand acts as a sink of phytoplankton due to bivalves' filtration, and a source of ammonia, exporting about 40% more than the input flux. These results suggest significant ammonia regeneration. Results show that despite the long and almost continuous spawning season, only a few cohorts are able to survive. Early stage mortality (top-down), in particular cannibalism and shrimp predation, can control the persistence of new cohorts in the first month although starvation (bottom-up) represents the main cause of biomass loss in an overall. The tendency is that new mussel beds are formed in areas adjacent to already existing mussel beds and channel edges. Bivalves' activity intensifies the seasonal patterns of food and nutrients in areas close to the mussel beds, though not changing their overall spatial distribution. This study not only confirms but also quantifies mussels' potential to influence ecosystem functioning due to their role in nutrient cycling. As the first integrated modelling study that focus on the mussels' beds in the Balgzand, the main difficulties on the model design, setup and results analysis were overcome. The model can now be used further, tested and improved in the same or other systems in order to serve as an effective and reliable scientific and management tool.

Understanding Environmental Changes in Temperate Coastal Seas: Linking Models of Benthic Fauna to Carbon and Nutrient Fluxes

“…The models include energy reserves and structural tissue (e.g., shells) as separate state variables, allowing for a mechanistic description of energy distribution and conservation and varying C:N:P ratios within the individual. There are a few examples of DEB models integrated into in biogeochemical-hydrodynamic models used to study the effects of bivalves on nutrient cycles in coastal areas (Maar et al, 2009;Grangeré et al, 2010;Ren et al, 2010;Saraiva et al, 2017), but their more extensive use in this context is probably hampered by their complexity (Brown et al, 2004a;Filgueira et al, 2011), and because they require parameters that are difficult to derive from commonly measured rates (van der Meer, 2006).…”

“…Supply and successful establishment of pelagic larvae may be an important factor limiting species occurrence and biomass especially in enclosed coastal areas (Barnes, 1994;Palmer et al, 1996). Saraiva et al (2017) showed the importance of larval recruitment and survival for blue mussels Mytilus edulis in the Wadden Sea using a DEB model coupled to a 3D hydrodynamic-biogeochemical model.…”

Validation of the 3D-MOHID Hydrodynamic Model for the Tagus Coastal Area

“…The versatility and flexibility of the MOHID Water eases its implementation in any type of system and to accomplish different modelling requirements depending on the objectives of the work to be performed. Indeed, in the last four years the MOHID Water was applied in multiple studies worldwide, namely in Canada [13], Colombia [14,15], Brazil [16], Argentina [17,18], Uruguay [19], Holland [20], France [21], Spain [22], Croatia [23], Australia [24,25], Malaysia [26] and Korea [27]. In Portugal, this model has been implemented in the entire Portuguese coast [28][29][30] and in all main estuaries [31][32][33][34][35].…”

Applicability of Dynamic Energy Budget (DEB) models across steep environmental gradients

“…For instance, marine mussels, which have long served as DEB theory model species 14 , are predominantly modelled under relatively stable subtidal conditions. While many DEB model applications have incorporated natural environmental variability, successfully capturing organisms’ physiological responses 15 – 17 , less attention has been given to explicitly testing model performance under steep gradients of environmental variability. Ignoring environmental variability can reduce the predictive power of energy budget models, and variability deserves special consideration when working with taxa subject to wide fluctuations in food and temperature, as recently highlighted for terrestrial and semi-aquatic species 18 , 19 .…”