According to the Serbian business publication Parametar, the Adriatic Sea is warming not only near the surface—scientists have recorded an unprecedented rise in temperature in the deep layers of the Southern Adriatic, including at depths of about 1,000 meters.
A study by an international team of oceanographers showed that over the past decade, the temperature of the bottom waters of the South Adriatic Basin has risen by 0.8 °C. At the same time, salinity has increased significantly.
For the study, scientists combined observational data collected since 1957, measurements from deep-sea stations, and data from 15 autonomous buoys of the international Argo system.
Over the long-term period from 1957 to 2024, the temperature at a depth of 1,000 meters increased by an average of 0.088 °C per decade.
However, this process has accelerated sharply in recent years.
According to Argo data, between individual deep-water renewal cycles, the rate of temperature increase at a depth of 1,000 meters was approximately 0.40°C per decade in 2012–2016, 0.67 °C in 2018–2021, and 0.64 °C in 2022–2024.
Another clear indicator of the scale of these changes is the penetration of warm water to greater depths. In the early 2010s, the 14 °C isotherm was located at a depth of approximately 100 meters, but by 2024, water at that temperature had spread nearly to the bottom of the South Adriatic Basin.
Changes were even recorded at a depth of 1,200 meters. During the deep-water turnover in 2022, the temperature there rose by approximately 0.4°C, while salinity increased significantly.
Researchers describe what is happening as an unprecedented warming and salinization of the Adriatic’s deep waters. The observed changes are occurring much faster than predicted by regional climate models with high emissions scenarios.
The Southern Adriatic is of particular importance to the entire sea. It is home to a deep basin reaching 1,200 meters, where the deep water masses of the Adriatic are formed and redistributed.
Therefore, the changes taking place there may affect more than just water temperature. Scientists warn of potential consequences for marine biogeochemistry, water circulation, and living organisms.
For countries along the Adriatic coast—specifically Montenegro, Croatia, Albania, and Italy—this means that climate change in the sea can no longer be assessed solely by the water temperature at beaches in the summer. The transformation affects virtually the entire water column and represents a long-term change in the marine system itself.
A separate study of temperature trends in the Mediterranean Sea also showed that the Southern Adriatic stands out among deep-water regions. In the 700–2,000-meter depth layer, warming of 0.058 °C per year was recorded here between 2013 and 2020—one of the most pronounced rates in the deep layers of the Mediterranean.
Source: Limnology and Oceanography Letters
