水産養殖研究開発ジャーナル

概要

A Modelling Approach to Estimate the Environmental and Productive Carrying Capacity for a Mediterranean Coastal Marine Culture Park

Campuzano FJ *,Gutiérrez JM ,Senabre T ,Mateus MD ,Perán A ,Belmonte A ,Aliaga V ,Neves R

Fish farming activities are a relevant economic coastal resource in the warm oligotrophic Mediterranean waters. This work describes the application of a numerical model to determine the carrying capacity of a mixed gilthead seabream (Sparus aurata) and European seabass (Dicentrarchus labrax) culture in a Marine Culture Park, located in the coast of the Region of Murcia (SE Spain). The MOHID modelling system was used to simulate the hydrodynamics and ecological conditions of the study area, and to address the processes related to fish farming activities such as pellet deposition of different sizes, nutrient recycling and oxygen consumption. The productive carrying capacity (PCC) and the environmental carrying capacity (ECC) were evaluated under different production scenarios with critical values for the culture and the environment. The selected indicators to assess PCC were the toxic level of ammonia species and the dissolved oxygen concentrations necessary for cultured fish survival. The ECC was assessed by means of eutrophic levels both in the sediment and the water column and the tolerance of benthic organisms to organic matter sedimentation. Results led to the definition of the minimum distances between installations, so to minimize their negative interactions, and to the quantification of the influence of dissolved and particulate products on the production. Finally, it was evaluated the capacity of the aquatic system to maintain the simulated biomass without undesirable environmental disturbance. The methodology employed in this work can be adapted to any system and cultured species, thus providing significant support to management decisions regarding the intensity of fish farming activities.