Investigation of a novel approach for aquaculture site selection

Abstract

7This study investigated the potential use of two "species distribution models" (SDMs), 8Mahalanobis Typicality and Maxent, for aquaculture site selection. SDMs are used in 9 ecological studies to predict the spatial distribution of species based on analysis of 10 conditions at locations of known presence or absence. Here the input points are aquaculture 11 sites, rather than species occurence, thus the models evaluate the parameters at the sites 12 and identify similar areas across the rest of the study area. This is a novel approach that 13 avoids the need for data reclassification and weighting which can be a source of conflict and 14 uncertainty within the commonly used multi-criteria evaluation (MCE) technique. Using 15 pangasius culture in the Mekong Delta, Vietnam, as a case study, Mahalanobis Typicality 16 and Maxent SDMs were evaluated against two models developed using the MCE approach. 17Mahalanobis Typicality and Maxent assess suitability based on similarity to existing farms, 18 while the MCE approach assesses suitability using optimal values for culture. Mahalanobis 19 Typicality considers the variables to have equal importance whereas Maxent analyses the 20 variables to determine those which influence the distribution of the input data. All of the 21 models indicate there are suitable areas for culture along the two main channels of the 22 Mekong River which are currently used to farm pangasius and also inland in the north and 23 east of the study area. The results show the Mahalanobis Typicality model had more high 24 scoring areas and greater overall similarity than Maxent to the MCE outputs, suggesting, for 25 this case study, it was the most appropriate SDM for aquaculture site selection. With suitable 26 input data, a combined SDM and MCE model would overcome limitations of the individual 27 approaches, allowing more robust planning and management decisions for aquaculture, 28 other stakeholders and the environment. 29 30

Classification of Areas Suitable for Fish Farming Using Geotechnology and Multi-Criteria Analysis

“…A procedure was created to establish a score for each criterion in the model. These criteria were reclassified and scored, as shown in Table 1, similar to the method used by Falconer et al [28], in which a categorical scale was adopted. On this four-point scale, a 1 was "largely unsuitable," a 2 was "slightly suitable," a 3 was "suitable," and a 4 was "highly suitable."…”

Land Suitability for Sustainable Aquaculture of Rainbow Trout (Oncorhynchus mykiss) in Molinopampa (Peru) Based on RS, GIS, and AHP

“…The key advantages of MCE techniques are that they are well established for aquaculture zoning, they can combine multiple criteria (many more than those used in this study; [19,20,55]), and may develop models under different hierarchies, priorities, and scenarios [8]. However, the main problem in the analysis of land suitability for aquaculture in ponds dug in the soil, and in general for any activity, lies in the lack of spatial data of the criteria [16].…”

“…The identification of the potential area for aquaculture should be based on favorable criteria to allow the growth of species of interest [5]. These criteria were established by considering rainbow trout breeding manuals from Peru [36] and FAO [37], land suitability studies for rainbow trout aquaculture [17,18], aquaculture of other species [8,16,19,[24][25][26], and the criteria for aquaculture zoning set by the FAO [5,13]. The same ones that were validated for the planning process by a group of experts, made up of five fish farmers in the study area and six aquaculture specialists from the DIREPRO-A of the PRODUCE.…”

Modelling seasonal nutrient inputs from non-point sources across large catchments of importance to aquaculture

“…Combining the NPS model outputs with site selection models or other modelling approaches (e.g. Ferreira et al, 2015;Falconer et al, 2016) could provide additional decision support for the industry and more holistic and objective planning.…”

“…Region-wide planning which considers the entire production area, or potential production area, is important for the ecosystem approach to aquaculture (EAA) (Soto et al, 2008;Ross et al, 2013;Brugère et al, 2018). But, this may present a challenge where key aquaculture production areas extend throughout large catchments such as the Mekong Delta (Falconer et al, 2016). NPS loading is an issue that should be considered at both local and larger catchment or regional scale.…”