MEDITERRANEAN

Rising sea temperatures in Turkey could force relocation of sea bass and gilthead seabream farms

Turkey, 2 April 2025 | İskenderun and Antalya are already experiencing over 50 days a year with sea temperatures exceeding 30 °C

Acuicultura de jaulas flotantes en Grecia

While current sea temperatures in Turkey remain within tolerable limits for farming key species such as gilthead seabream (Sparus aurata) and European sea bass (Dicentrarchus labrax), a recent study by Mehmet Fatih Can and Yavuz Mazlum from Iskenderun Technical University, and published in Aquaculture International, warns of a worrying trend: a sustained rise in sea surface temperatures—driven by climate change—could threaten the long-term viability of marine aquaculture in some of the country’s most productive regions.

With over 150,000 tonnes of annual output and strong export market across Europe, Turkey stands as one of the Mediterranean’s leading producers of farmed seabream and sea bass. However, the study suggests that this dominant position could be at risk unless timely adaptation strategies are implemented.

The researchers examined sea surface temperature data from 1982 to 2020 across four key coastal zones- İzmir, Antalya, İskenderun and the Black Sea-and modelled projections through to 2080. Hotspots such as İskenderun and Antalya are already seeing more than 50 days per year where water temperatures exceed 30ºC, the upper threshold for these species’ thermal tolerance. In İskenderun, the figure rose to 74 days in 2020 alone.

Projections paint an even more alarming picture for the decades ahead. If current trends continue, these regions could face between 170 and 180 days per year above the critical temperature threshold by 2080. According to the authors, such conditions would pose a serious threat not only to fish health and welfare, but also to local economies reliant on aquaculture.

In response, the study advocates for relocating marine farms away from the most affected areas, and shifting operations to regions with more stable thermal conditions, such as İzmir or the Black Sea, where temperatures remain safely within acceptable limits.

One of the key findings in the thermal buffer offered by deeper waters. In Antalya, for example, temperatures at depths of 40-50 metres can be up to 9ºC cooler than at the surface, offering a potential lifeline for farms willing to modify their floating cage system to operate at greater depths.

Among the study’s core recommendations is the need to incorporate climate modelling into site planning, enhance real-time temperatures monitoring systems, and diversify production towards more heat-resilient species.

The authors also call for greater investment in technologies that promote resilience and flexibility in the face of accelerating environmental change.

Though the study focuses on Turkey, its message resonates across the wider Mediterranean basin, including Spanish waters. As climate change continues to reshape marine environments, Mediterranean aquaculture must adapt-not just to survive, but to remain competitive and sustainable in the long term.