The COMBISTRESS project, involving the University of Cadiz (UCA), is assessing how the combination of rising water temperatures and the presence of nanoplastics may affect the health and growth of sea bream in aquaculture facilities. This national initiative, coordinated by the Autonomous University of Barcelona (UAB), is funded by the State Research Agency and European FEDER funds.
The sub-project in Cadiz is led by professor Juan Miguel Mancera, from the Faculty of Marine and Environmental Sciences and researcher at the Marine Research Institute (INMAR). The objective is to understand how aquaculture fish respond to increasingly complex environmental scenarios, marked by climate change and growing marine pollution, by analyzing the interaction of factors such as temperature increase, nanoplastics in diet or water, high stocking densities, salinity changes, and fasting periods.
Sea bream (Sparus aurata) is used as an experimental model. Preliminary results from the UCA indicate that rising water temperature is the factor with the greatest influence on fish growth and physiological status. While higher temperatures promote increased growth, they also lead to more intense use of energy reserves, reflecting greater physiological effort to sustain metabolic rates.
Trials on nanoplastic incorporation into the diet have not shown significant short-term effects on growth or main productive indicators. However, alterations in certain metabolic, immune, and cellular parameters have been observed, suggesting potential physiological effects that require longer-term studies. The UAB team has detected nanoplastic accumulations in specific tissues and metabolic changes associated with the interaction of both factors.
A central aspect of the project is the joint evaluation of different environmental stressors, aiming to more accurately replicate the real conditions that fish may face in current and future aquaculture operations where multiple pressure factors often coincide. Advances were presented at the intermediate meeting of COMBISTRESS, held during the XX National Aquaculture Congress in Vigo, where participating teams reviewed results and coordinated upcoming trials.
Ongoing experiments aim to identify which nanoplastic exposure pathways—through water or feed—have the greatest impact and how they influence sea bream health and welfare in the medium and long term. This information could be relevant for adapting cultivation conditions and anticipating potential risks in a context of environmental change. The research is of particular interest to the province of Cadiz, given its significant aquaculture and marine research activities.
