The Thermaikos Gulf, the largest gulf in the Aegean Sea, is one of the most significant aquatic ecosystems in Northern Greece. Protecting such a crucial ecosystem must inevitably be a part of any city’s resilience and adaptation strategy.
Research by G. Krestenitis, G. Androulidakis, Ch. Makris, K. Kompiadou, and others has identified the Thermaikos as a Mediterranean hotspot where water temperatures have risen dramatically over the last 50 years due to climate change. This has had severe repercussions for marine species and aquaculture.
Specifically, according to Yiannis Krestenitis, Emeritus Professor of Coastal Engineering and Oceanography at the Department of Civil Engineering of Aristotle University of Thessaloniki, “In the summer of 2021, we witnessed an exceptional increase in the Gulf’s water temperature, leading to mass mortality, including in mussel farms in the western region. Mussel farmers lost over half their production”.
Beyond its impact on productive sectors, this situation has also affected marine life in the Gulf, primarily due to limited water renewal. Phytoplankton blooms (red tides) and the accompanying unpleasant odors exacerbate the worrying state of the Thermaikos, despite proposals to improve its water quality in the draft of the 2nd Revision of the River Basin Management Plans. Moreover, these problems complicate daily life and worsens the quality of life for Thessaloniki’s residents.
Although a memorandum of cooperation was signed in December 2023 between the Ministry of Macedonia and Thrace and the Natural Environment and Climate Change Agency (NECCA) to protect and sustainably develop the Thermaikos, Mr. Krestenitis has previously emphasized that surface cleaning alone is insufficient to improve the Gulf’s water quality.
In addition to climate change, the Thermaikos suffers significant pollution from human activities. Agricultural practices, drainage, and industrial activities in the region contribute heavily to the Gulf’s degradation. Despite advances in biological treatment and waste management, uncontrolled pollution sources persist and must be identified and addressed.
Krestenitis, in conversation with Alterthess, stresses the need for a comprehensive master plan to manage the Thermaikos’ pollution, which has been pending for years.”We know from the Central Macedonia River Basin Management Plans that a master plan for the Thermaikos was proposed. It was never developed, and it is mentioned again in the revised plans as pending. Yet, we are already halfway through 2024, and there is no information about this essential master plan that has been acknowledged as necessary since 2018″.
Such a plan would clearly identify the sources contributing to the Gulf’s pollution while proposing measures to reduce pollutants, whether from agricultural activities, drainage, runoff, or other sources. Krestenitis also criticizes the current monitoring conducted by the National Water Monitoring Network as inadequate, emphasizing the need to expand the network.
Another significant issue facing the Gulf of Thessaloniki is coastal erosion caused by rising sea levels and changing wave patterns in the coastal zone. This erosion is far from benign, as it not only reduces beach areas but can also impact infrastructure near the shore. This situation highlights Greece’s reluctance to incorporate the Barcelona Protocol into national legislation, which mandates at least 100 meters of undeveloped coastal buffer zones.
Coastal erosion in the Thermaikos is expected to intensify in the coming years due to climate change. While the Region of Central Macedonia has established an Observatory for the Prevention and Management of Coastal Erosion Risks, it has yet to announce specific measures or plans to address the issue. “Nature-based solutions are needed”, says Krestenitis, “such as expanding the free coastal zone, but unfortunately, this does not seem to be a political priority at the moment”.
Listen to the podcast “Thermaikos: Boiling and polluted”, where we discuss the issue in detail with Y. Krestenitis
A particularly contentious issue is the proposed installation of a floating LNG terminal in the Thermaikos. Mr. Krestenitis notes that such a facility contradicts efforts to phase out fossil fuels and warns of the enormous risks posed by such a station’s proximity to the city. Furthermore, given that LNG terminals use seawater to heat and vaporize the liquefied gas, there is a significant risk of further degrading the Gulf’s waters.
We spoke with environmental scientist Kostas Nikolaou, PhD. of Environmental Science and former visiting professor at Aristotle University of Thessaloniki, who also raises serious concerns about these plans. He warns of potentially catastrophic consequences, such as fires, and highlights issues of both water and air pollution (e.g., methane leakage).
Adaptation to climate change, which should prominently include the protection of the Thermaikos, needs to occur at a regional level. While the Region of Central Macedonia has developed a Regional Climate Change Adaptation Plan (PESPKA), Krestenitis notes that it does not clearly prioritize Thermaikos. However, he identifies a more significant problem:
“The plan has not undergone the necessary consultation with all stakeholders, civil groups, scientists, and productive sectors, so that everyone understands the anticipated impacts of climate change, the measures needed, and, most importantly, achieves consensus on these measures. Only by doing so can we approach climate change adaptation optimistically and effectively”.
Research and editing: Jason Bantios, Stavroula Poulimeni, Tilemachos Fassoulas
Up next: The Missed Opportunities for More Green Space in Thessaloniki
The research of the independent media cooperative Alterthess titled “Urbal Resilience, Climate Neutrality: The case of Thessaloniki” was realised with the support of Rosa Luxemburg Stiftung-Office in Greece. Read the complete research here.
