The benthic environmental footprint of aquaculture in the Eastern Mediterranean: Organic vs conventional fish farming

Abstract

A field experiment was carried out in a fish farm of the Eastern Mediterranean in order to evaluate the benthic environmental footprint of the organic versus the conventional fish farming. The highest values of chl α were recorded at the conventional culture during both studied seasons. The organic matter and organic carbon rates recorded at the conventional culture were significantly higher than those observed at the organic culture in both studied seasons (p < .05). Furthermore, in all cases the quality characteristics of benthic community variables were optimum at the organic culture compared to the conventional one and similar to those of the control. SIMPER analysis showed that the maximum average dissimilarity occurred between organic and conventional culture, while the main contributor species for this dissimilarity was the polychaete Capitella capitata. Multidimensional scaling (MDS) ordination plot indicated clearly a separation of the organic and conventional fish farming during both studied seasons. K-dominance curves revealed a clear difference in elevation, mainly during summer. M-AMBI index showed a poor to moderate environment for conventional culture, while organic one was good to high and similar to the control site (high). The results indicated the lower environmental footprint of the organic fish farming compared to the conventional, demonstrating its potential as an important management tool, which could play a significant ecological role for the sustainability of aquaculture in the Mediterranean region.