Circularity Assessment in Aquaculture: The Case of Integrated Multi-Trophic Aquaculture (IMTA) Systems

Abstract

Aquaculture is a strategic sector that aims to meet the increased demands for healthy food for current and future populations. However, this progression needs to be sustainable, which can potentially be achieved by the implementation of circular practices. Integrated multi-trophic aquaculture (IMTA) systems promote the incorporation of circular principles. Nevertheless, the lack of harmonized definitions and standards impedes the quantification of these circular attributes. This study aims to explore the potential principles embedded in IMTA and the existing alternatives to quantify circularity. Two basic pillars (nutrient management and resource use efficiency) were identified as the most relevant circularity attributes for IMTA systems and were quantified through aquaculture-specific indicators. Bioremediation indicators, together with the efficiency indicators in terms of feed, water, energy, and infrastructure materials used, were selected to evaluate the circularity performance of four IMTA trials in three aquaculture facilities in Ireland, Brazil, and South Africa. Salmon, white shrimp, tilapia, abalone, and sea urchins were studied and cultivated together in various combinations with several low-trophic species in these IMTA trials to evaluate the improvement in circularity compared with corresponding monoculture conditions. The results showed an increase in circularity of up to 90% in terms of water recirculation, as well as bioremediation, which was improved by 80%–90%, providing evidence for the potential role of IMTA in the circularity transition.

Regional Dynamics and Economic Sustainability of Mariculture Firms in Portugal: A Financial Performance Analysis

“…Size Trends: The study's findings regarding the financial performance of larger versus smaller firms resonate with the literature on economies of scale versus flexibility [13,44]. Balancing these factors is essential for firms of all sizes to thrive, as emphasized in prior research [16].…”

“…However, Integrated Multi-Trophic Aquaculture (IMTA) systems are increasingly recognized for their potential to enhance sustainability in mariculture. Studies discuss the implementation of IMTA and its environmental and economic assessment, as well as challenges and methodologies for sustainability evaluation [14][15][16][17].…”