Ecosystem modelling for ecosystem-based management of bivalve aquaculture sites in data‑poor environments

Abstract

Although models of carrying capacity have been around for some time, their use in aquaculture management has been limited. This is partially due to the cost involved in generating and testing the models. However, the use of more generic and flexible models could facilitate the implementation of modelling in management. We have built a generic core for coupling biogeochemical and hydrodynamic models using Simile (www.simulistics.com), a visual simulation environment software that is well-suited to accommodate fully spatial models. Specifically, Simile integrates PEST (model-independent parameter estimation, Watermark Numerical Computing, www. pesthomepage.org), an optimization tool that uses the Gauss-Marquardt-Levenberg algorithm and can be used to estimate the value of a parameter, or set of parameters, in order to minimize the discrepancies between the model results and a dataset chosen by the user. The other critical aspect of modelling exercises is the large amount of data necessary to set up, tune and ground truth the ecosystem model. However, ecoinformatics and improvements in remote sensing procedures have facilitated acquisition of these datasets, even in data-poor environments. In this paper we describe the required datasets and stages of model development necessary to build a biogeochemical model that can be used as a decision-making tool for bivalve aquaculture management in data-poor environments.

Comparison of Remotely-Sensed Sea Surface Temperature and Salinity Products With in Situ Measurements From British Columbia, Canada

“…There is a need for broad-scale oceanographic data to support assessment and management of stocking density, farm-fallow cycles, and fish health. These data are also critical for establishing the initial and boundary conditions of ecosystem models used for ecosystembased management, allowing assessment of ecological carrying capacity and environmental effects (Filgueira et al, 2013). Environmental data (e.g., water temperature and salinity) are often recorded at farm sites, but often in situ data have missing values, while corresponding in situ data for wild salmon habitat rarely exist.…”

Storm‐induced changes in coastal geomorphology control estuarine secondary productivity

“…A corresponding threshold of sustainability was objectively established based on ecological resilience and the precautionary principle [ UNESCO , ]. We assumed that natural annual variation in chlorophyll in the absence of aquaculture defines the limit of acceptable change [Figure 1 in Filgueira et al ., ]. Outside of this envelope, increased chlorophyll depletion caused by suspension feeder grazing could exceed a tipping point beyond system resilience [ Grant and Filgueira , ], forcing reorganization in ecosystem function [ Crowder and Norse , ].…”

“…Outside of this envelope, increased chlorophyll depletion caused by suspension feeder grazing could exceed a tipping point beyond system resilience [ Grant and Filgueira , ], forcing reorganization in ecosystem function [ Crowder and Norse , ]. The natural variation of chlorophyll concentration in Tracadie Bay is 27%, derived from a previous analysis [ Filgueira and Grant , ] and used as a precautionary threshold to maintain a sustainable level of aquaculture activity [Figure 1 in Filgueira et al ., ]. Therefore, a depletion index below −27% (no depletion = 0% and sustainable threshold = 0%–27% = −27%, Figure ) would suggest that shellfish aquaculture pressure on phytoplankton population might compromise the ecosystem resilience, potentially causing negative ecological effects.…”

Is integrated multitrophic aquaculture the solution to the sectors’ major challenges? – a review

“…Other mathematical models are available to predict the yield, environmental impact and economic optimisation of shellfish aquaculture (e.g. Brigolin et al 2009;Ferreira et al 2009;Giles et al 2009;Ren et al 2010;Filgueira et al 2013).…”