Meat Quality of European Flat Oyster Cultivated at Different Distances From Finfish Cages in a Mediterranean Integrated Multi‐Trophic Aquaculture (IMTA) System

This study examines the nutritional profile of European flat oysters (<i>Ostrea edulis</i>) cultivated in an Integrated Multi-Trophic Aquaculture (IMTA) system in Gaeta, Italy. Oysters were deployed for 257 days, 8 July 2023-21 March 2024, at two distances from gilthead seabream (<i>Sparus aurata</i>) cages: 20 m, representing high exposure to fish-derived waste, and 800 m, reflecting reduced waste influence and greater phytoplankton availability. The objective was to evaluate how proximity to fish cages, combined with seasonal variability, influences oyster nutritional quality and to identify optimal spatial arrangements in IMTA systems. Sampling occurred in summer, autumn, winter, and spring to capture seasonal changes in physiology and nutrition. Oysters at the distant site showed consistently higher nutritional quality, attributed to greater phytoplankton access and dilution of fish waste. Crude protein content ranged from 4.49% to 7.81%, with the highest values recorded at the distant site. Crude lipid levels peaked at 1.31% in March, linked to prereproductive nutrient accumulation. Arginine and lysine were the most abundant essential amino acids (EAAs), with significantly higher arginine levels at the distant site during late autumn and early spring. These findings emphasize the spatial planning and seasonality in IMTA, supporting sustainable aquaculture, ecosystem services, and nutrient-rich seafood production.