Geographical information systems-based models for offshore floating marine fish cage aquaculture site selection in Tenerife, Canary Islands

Citation

Perez OM, Telfer T & Ross L (2005) Geographical information systems-based models for offshore floating marine fish cage aquaculture site selection in Tenerife, Canary Islands. Aquaculture Research, 36 (10), pp. 946-961. https://doi.org/10.1111/j.1365-2109.2005.01282.x

Abstract
The present study focuses on the development of a standard methodology for selection of suitable sites for offshore (exposed) marine fish-cage farming (floating cages) of seabream (Sparus aurata) and seabass (Dicentrarchus labrax) in an island environment, using Tenerife as an example. Site selection is a key factor in any aquaculture operation, affecting both success and sustainability and can solve conflicts between different activities, making a rational use of the coastal space. Site selection was achieved by using geographical information systems (GIS)-based models and related technology to support the decision-making process. The framework for spatial multicriteria decision analysis used in this study began with a recognition and definition of the decision problem. Subsequently, 31 production functions (factors and constraints) were identified, defined and subdivided into eight submodels. These were then integrated into a GIS database in the form of thematic layers and later scored for standardization. At this stage, the database was verified by field sampling to establish the quality of data used. The decision maker's preferences were incorporated into the decision model by assigning weights of relative importance to the evaluation under consideration. These, together with the thematic layers, were incorporated using multicriteria evaluation techniques and simple overlays to provide an overall assessment of possible alternatives. The integration, manipulation and presentation of the results by means of GIS-based models in this sequential and logical flow of steps proved to be very effective for helping the decision-making process of site selection. Tenerife has very favourable environmental conditions for culture of marine fish and there are no totally unsuitable sites for cage farming identified in this study. On the other hand, there are few very suitable sites (high scores) either, principally due to the heavy use of the coastline and the conflicts between different users. From the 228 km2 of available area for siting cages in the coastal regions with depth less than 50 m, the total area suitable for siting cages (scores 6-8) was 37 km2. There are only 0.51 km2 of very suitable areas (score 8) and approximately 5.37 km2 of suitable (score 7), most of these being located in the southeast of the island. These relatively small areas of suitability should be put into the context of the wider use of the coastal environment around Tenerife.

Keywords
site selection; aquaculture; cage culture; GIS; Tenerife

Journal
Aquaculture Research: Volume 36, Issue 10