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The development of spatial planning and management approaches is required to increase the space available for aquaculture production and to support the increasing global demand for food resources. During a European funded project, a large consultation exercise highlighted that stakeholder involvement is a necessity for successful planning and must be a continuous process as part of the development of a decision-making tool. In this study we present a decision support tool built on a web based dynamic interface to Geographic Information Systems which facilitates access to information related to site selection, environmental interactions and management in aquaculture. It is derived from the AkvaVis concept and uses interactive functions that instantly display the results of spatial parameters chosen by the user. We adapted the tool for use within four case studies which deal with very different scales of aquaculture and issues related to aquaculture in four different countries. The key strengths of our tools relate to their capacity to manage and display spatial data from different sources in a transparent way, the ability to use and display a series of built-in indicators, and the long-term development potential made possible by the maintenance strategy of the tools, services and data depository. Consultations and meetings provided an accurate view of stakeholder expectations as well as feedback on the tool development and applicability, therefore helping the tool to meet the prerequisite for operational decision-making tools. Image 1 • Web-based tools have been adapted to help aquaculture planning in four countries. • The tools display spatial data regarding marine environment and other uses. • Spatial data are used within built-in indicators of areas suitable for aquaculture. • Stakeholders have been involved to identify aquaculture issues and key data. • Transparency and long-term maintenance are key to aquaculture management. [ABSTRACT FROM AUTHOR]

Abstract: Many studies based on bioenergetics growth models have investigated the effects of environmental factors on oyster (Crassostrea gigas) growth and physiology. However, most of these models are site-specific and cannot be applied to other culture sites without the re-estimation of parameters or re-formulation of some processes. We aimed to develop a generic growth model suitable for application in contrasting environments, with a constant set of parameters. We tested the oyster-DEB model (Bourlès et al. 2009) for the stimulation of C. gigas growth in different cohorts (spats and adults) at major shellfish culture sites in France, in several years: Arcachon (1993–1994); Marennes-Oléron (2007); Quiberon (1999, 2000, 2001); Brest Harbour (2008); Mont-Saint-Michel Bay (2003); Baie-des-Veys (2002). These different ecosystems offer a wide range of values for the two forcing variables of the model: water temperature (range: 6-24°C) and phytoplankton concentration (annual average: 110–700×103 cell L-1). The validation data (dry flesh mass of C. gigas) were obtained from various growth surveys carried out by IFREMER. The oyster-DEB model simulated the oyster growth dynamics of both spat and adult stages of C. gigas accurately over time at the various culture sites. The model captures: i) the active spring growth; ii) the timing and amplitude of spawning events; and iii) the lean periods (i.e. loss of dry flesh mass) in autumn and winter. The half-saturation coefficient X k is the only model parameter that varied between sites and years. This environment-specific coefficient reflects variability in the food of the oysters: quantitative and qualitative effects of the inorganic material and of the phytoplankton species on the feeding response of C. gigas. With a single set of parameters (other than for X k ), this is thus the first bio-energetic growth model for C. gigas robust enough and of a sufficiently generic nature for the accurate simulation of oyster growth in different Atlantic ecosystems. [Copyright &y& Elsevier]