Introduction
Aquaculture industry is a strategic development sector of the blue economies, considering the huge amount of seafood consumption in the EU, but only 20% comes from EU farms (EUMOFA, 2018). Indeed, the sector is stagnating due to different problems, such as administrative, environmental, and technical criticalities. In order to promote a sustainable, innovative and competitive aquaculture, a spatial planning should be carried out to highlight the most suitable areas to this activity. In this framework the identification of the Allocated Zones for Aquaculture (AZAs), areas where aquaculture has priorities over other uses (Sanchez-Jerez et al., 2016), can booster this sector. An AZA is a planning system that considering the environmental, social, and economic components, allowing to highlight the most suitable areas to specific farming activities.
In 2020, in Sardinia, started a project about the AZA identification (EMFF PO 2014-2020), with 3 main objectives: (i) improve the aquatic ecosystems knowledge; (ii) prepare the AZA regional plan; (iii) develop a Geoportal for managing and consulting data. Based on the regional resolution (Sardinian Region resolution 3/26 of 22/01/2020), the AZA have to be classified as follow: ZONE 1, areas suitable for aquaculture activities; ZONE 2, areas suitable for aquaculture activities subjected to regulation/limitation; ZONE 3, areas not suitable for aquaculture activities.
In this paper we present a framework for supporting the AZA identification in three aquatic ecosystems: at sea, in lagoons, and in lakes.
Methods
The AZA plan pertained to the Sardinian territorial sea waters (SW), lagoons (LG) and lakes (LK). A tiered approach was developed that first assessed the availability of the three aquatic ecosystems for aquaculture. Following this, in the areas considered to have good availability for aquaculture, the suitability for different species was estimated. In these ecosystems data about chemical-physical water characteristics, habitat distribution, and current uses were collected. Data were extracted from regional agencies database (in situ data), remote sensing database (i.e.: CMEMS), and cartographic data gathered from different sources (e.g.: Sardinian Geoportal and EMODnet).
In the three aquatic ecosystems, the species considered were: European seabass (SW, LG), gilthead seabream (SW, LG), Mediterranean mussel (SE, LG), Pacific oyster (SW, LG), flathead grey mullet (LG), grooved carpet shell (LG), rainbow trout (LK), brown trout (LK), carp (LK), perch (LK), tench (LK), largemouth bass, and striped bass (LK).
At sea, the AZA were identified applying the Spatial Multi-Criteria Evaluation methodology (Brigolin et al., 2017; Porporato et al., 2020), considering 4 criteria: potential growth, distance to harbour, significant wave height, bottom typology. Protected habitats distribution, sea uses, and potential conflicts, with their specific buffer zone, were also considered. Subsequently, in 3 different zoom areas, namely Porto Torres, Olbia, and Palmas gulf (Fig. 1A), a dispersion index for finfish farms was estimated. Finally, the Cumulative Effect Assessment and the Maritime conflict analysis tools, based on the Tools4MSP Modelling Framework (Menegon et al., 2018), were applied in the Porto Torres area.
In lagoons and lakes, firstly the aquaculture suitability was estimated combining 2 methodologies, the fuzzy logic classification and the factorial analysis. In these systems biological (e.g.: temperature, oxygen) and logistic criteria (e.g.: site accessibility and facilities) were considered. Subsequently, depending on these first results, in depth analyses in 3 lagoons and in 2 lakes were carried out. Pacific oyster carrying capacity in the three lagoons was calculated using data on water movement and food availability. In the lakes, the suitability of Sardinian reservoirs for rainbow trout aquaculture was evaluated through seasonal field samples of temperature and oxygen at different locations and depths.
In parallel to the previous described analyses, in order to draft a participatory AZA plan, and to select the zoom areas, different stakeholders, including local authorities, farmers, the scientific community, and the general public, were involved in different events.
Results and discussion
The main results of the aquaculture suitability estimated for the 3 aquatic ecosystems are show in Fig. 1. A Geoportal based on GeoNode, containing data and tools was developed (www.waterspatialplanning.eu). Our research was aimed at identifying the environmental, social, and economic conditions that allow the development of a sustainable aquaculture, guaranteeing the environmental protection, and the reduction of potential conflicts between different uses, facilitating synergies and co-uses.
The obtained results will be used to draft the AZA Sardinian plan which will be instituted by the competent authority. Spatial planning and the choice of areas has been based on the use of scientific, environmental, legal, technical and socio-economic evidence, to guarantee the conservation and protection of the environment and territories, maintaining a good ecological status, and preventing habitat and ecosystem degradation.
Our approach, thanks to the generality and transferability of the applied methodology could be applied to the AZAs identification in other case studies.
References
Brigolin, D., Porporato, E. M. D., Prioli, G., & Pastres, R. (2017). Making space for shellfish farming along the Adriatic coast. ICES Journal of Marine Science, 74(6), 1540-1551.
EUMOFA (2018). Il mercato ittico dell’UE. Commissione Europea, Direzione Generale degli Affari marittimi e della pesca (Ed.). 128 pp.
Menegon S, Sarretta A, Depellegrin D, Farella G, Venier C, Barbanti A. (2018). Tools4MSP: an open source software package to support Maritime Spatial Planning. PeerJ Comput Sci;4:e165.
Porporato, E., Pastres, R., & Brigolin, D. (2020). Site suitability for finfish marine aquaculture in the central Mediterranean Sea. Frontiers in Marine Science, 772.
Sanchez-Jerez, P., Karakassis, I., Massa, F., Fezzardi, D., Aguilar-Manjarrez, J., Soto, D., ... & Dempster, T. (2016). Aquaculture’s struggle for space: the need for coastal spatial planning and the potential benefits of Allocated Zones for Aquaculture (AZAs) to avoid conflict and promote sustainability. Aquaculture Environment Interactions, 8, 41-54.