Maximum depth of more than 7,250 feet (2,210 metres)

The Black Sea is a body of water situated between Europe and Asia. Its border countries include Ukraine, Russia, Georgia, Turkey, and Romania. Its maximum depth is over seven hundred meters and it covers an area of more than forty-two thousand square kilometers. It is also linked to the Aegean Sea and the Mediterranean Sea. The Black Sea is shallow enough for diving but is otherwise unsuitable for swimming.

The Black Sea reaches a maximum depth of more than seven thousand feet, making it the second deepest ocean after the Arctic Ocean. The Black Sea is surrounded by mountains and has a shelf of water between one and twenty-five kilometers wide. At its deepest point, the Mariana Trench is more than 36,000 feet. There, scientists have discovered many organisms including bacteria, crustaceans, sea cucumbers, octopuses, and fishes. In the southern sector of the Black Sea, the maximum depth is over seven thousand feet.

Surface area

The Black Sea’s area has changed over time. In the past, it was a freshwater lake and some time after the last glaciation, it became a saltwater lake. Scientists have argued about the history of the Black Sea. However, there is little solid scientific evidence for the origins of its saltwater condition. The Black Sea was created around seven thousand years ago. It is currently the world’s largest anoxic lake, with about 90% of its water containing very little dissolved oxygen.

The Black Sea is the thirteenth largest sea in the world, with a surface area of approximately 436,400 square kilometers and a volume of about 547 cubic kilometers. It is a narrow body of water located between Asia and Europe. Its eastern and western borders include Russia, Ukraine, and Georgia. To the northeast, it is bounded by the Pontic Mountains. Its longest east-west extent is about 1,175 km.


The temperature of the water in the Black Sea varies considerably, depending on the region. In January, the water is nine to 11 degrees. It can be a couple of degrees colder in Odessa and Yalta. February and March have similar temperatures; the water is only three or four degrees above zero in Martov. The water temperature begins to rise in April and reaches thirteen or fourteen degrees above zero.

Annual SST anomalies for the deep sea and the western shelf are shown in Fig. 7. The SST anomalies are calculated from the monthly mean SST values. The yearly averages are shown in Fig. 7. Combined data from Yalta and Odessa weather stations are used for statistical calculations. As the graphs are uncluttered, the resulting temperature trends are clear. The cooling trend in the mid-1980s appears to have been caused by a series of “cold” years, a strong winter, and a negative SST anomaly.

The warming and cooling trends observed in the Black Sea are attributable to changes in the marine physical environment, especially regional variations in climate. However, there are many uncertainties surrounding the causes of these unusual temperature trends. In fact, despite numerous studies, it is still difficult to separate trends in the deep layers of the Black Sea because of the limited and low-quality data. That said, the climate of the Black Sea is likely to change over time.

Oxygen dynamics

The current study has focused on the evolution of the oxic-anoxic boundary layer of the Black Sea, a region where the dissolved oxygen concentration fluctuates from saturation to zero. The resulting data reveal a pycnocline with a narrow and deep anoxic zone. The results also highlight the importance of mesoscale processes in the formation of the pycnocline.

In the past decade, there has been a decrease in the depth to which oxygen can penetrate the deep waters of the Black Sea. The average oxygen penetration depth has decreased from 140 m in 1955 to 90 m in 2015. This is the lowest annual value recorded during that time period. The researchers believe that the deep water oxygen dynamics of the Black Sea are closely linked to the changes in anthropogenic activities. Therefore, they recommend that future research should consider this relationship in interpreting the changes in the region.

The study also found that the oxic layer in the central basin was two times thinner than in the coastal zone and had minimal spatial variability. The oxic-anoxic water interface along the continental slope was represented by an isoline of five mM, and its depth changed by 75 m in a matter of weeks. The thickness of the oxygenated layer between isolines 50 and five mM was significantly different in the two basins, and the difference was easily visible.

Ancient shorelines

Scientists have discovered ancient Black Sea shorelines that were once freshwater lakes. This ancient coastline was likely buried beneath the waves more than seven thousand years ago. The discovery was made by scientists led by Professor Petko Dimitrov of the Institute of Oceanology in Varna, part of the Bulgarian Academy of Sciences. They studied the shoreline’s sonar images to determine its age. Researchers have found that the shoreline once was only a few feet below the current sea level, but they believe the ancient sand dunes were once higher.

The Black Sea has an interesting history. Many ancient civilizations once inhabited the shores. In addition to ancient shorelines, it contains tens of small islands and is home to an amazing flora and fauna. Today, the Black Sea is one of the most popular tourist destinations in the world. Its history and culture are rich and varied. No other ocean region has such rich history and diverse ecosystems. For this reason, it has become a popular travel destination.

Geologic history

The geologic history of the Black Sea has been shaped by large-scale sea level changes, large accumulations of sediments in the deep sea, and a change in climate over the centuries. The Black Sea and the Mediterranean were essentially at the same level at the start of the Holocene, a period of gradual and continuous rise in sea levels that resulted in the migration of many species from the Mediterranean to the Black Sea.

Recent sediments have a low diversity of coccolithophores, with E. huxleyi and Braarudosphaera dominating the Black Sea’s fauna. Other recent sediments, however, include a number of Discolithina species and Helicopondosphaera spp. Those two organisms are thought to have originated in the Mediterranean, where the Black Sea was influenced by the same climate changes as the surrounding continents.

The Black Sea’s water level has fluctuated significantly during its geologic history. It has sometimes been dry land, and now, connectivity can occur through the Turkish Straits. Before the Turkish Straits, the Black Sea was an endorheic basin. Although it is a basin with its own independent ecosystem, the Black Sea is still connected to the world’s ocean through the Caspian Sea. The water level of the Black Sea is relatively high and exchanged with the Mediterranean.

Marine life

The marine life in the Black Sea is much less diverse than that of the coral reef, but the comparatively small size makes it an ideal habitat for scientific research. Marine life in the Black Sea responds quickly to both natural and anthropogenic influences. Scientists can study the varying occurrences of the Black Sea’s ecosystem to gain a better understanding of its structure and functioning. The nutrient-poor water of the Black Sea is also a good model for alien marine species invasions.

The largest pelagic fish in the Black Sea are not common, but it is a very diverse marine ecosystem. Several species of wrasse live in these brown algae branches, and small marine snails slide along their twigs. Large stone crabs hide in the algal thalli, and schools of young mullets and Black Sea horse mackerel sweep over the crowns of this underwater forest.


The marine ecosystem of the Black Sea is dominated by phytoplankton, mainly diatoms and coccolithophores. The annual cycle of phytoplankton development in the Black Sea consists of diatom-dominated production in spring, followed by weak mixed assemblage development beneath the seasonal thermocline in summer, and a surface-intensified fall bloom. The Black Sea also contains a considerable amount of organic detritus and suspended matter.

There are several key problems related to the current state of the Black Sea’s oceanography. The observing infrastructure is insufficient and is not continuous. Consequently, there is a need for new technological innovations that can support the operational systems of the Black Sea. These innovations include improving satellite and in situ infrastructure, increasing modeling capabilities, assimilation and validation, and real-time monitoring and estimation of physical variables. In this way, the BSOS could contribute to the improvement of the quality of life of its citizens.

Several scientific studies are devoted to the black sea’s physical oceanography. A monograph titled “Black Sea Oceanography” was recently published, and it provides an overview of this complex region’s physics. The monograph is based on direct data, an extensive bibliography, and a dedicated dedication to Valentina Sergheevna Tujilchina. Despite being a monograph, the book is an excellent reference for students and researchers who are interested in the Black Sea’s marine environment.