Black Sea

The Black Sea is a large body of water between Europe and Asia. It sits east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. Six countries border the Black Sea: Bulgaria, Georgia, Romania, Russia, Turkey, and Ukraine.

Many important rivers flow into the Black Sea, such as the Danube, Dnieper, and Dniester. This makes the sea very important for the water systems of many European countries. The Black Sea covers a wide area and has very deep waters, reaching depths of over two miles in some spots.

The Black Sea connects to other seas through narrow waterways. The Bosporus links it to the small Sea of Marmara, which then connects to the Aegean Sea through the Dardanelles. To the north, the Kerch Strait connects the Black Sea to the Sea of Azov. These connections let water move in and out, creating interesting patterns in the sea’s currents and water layers.

Because of special conditions in its deep waters, the Black Sea helps preserve ancient shipwrecks. These shipwrecks can teach us about life in the past. Over millions of years, the sea’s water levels have changed, sometimes covering land that is now underwater. Today, the Black Sea is very important for both nature and human activity.

Name

The Black Sea has many names used by the countries around it. In English, we call it the "Black Sea".

In Greece, it is sometimes called the "Euxine Sea", meaning "Hospitable Sea". The name "Black Sea" may come from the dark color of the water.

Geography

The International Hydrographic Organization has rules for the Black Sea's borders. It lies between Europe and Asia, touching countries like Bulgaria, Georgia, Romania, Russia, Turkey, and Ukraine.

Many big rivers flow into the Black Sea. The most important ones are the Danube, Dnieper, and Dniester. These rivers help water the lands around the sea, which include parts of 24 countries.

The area near the Black Sea is called the Black Sea Region. The north has rich, dark soil called the Chernozem belt, stretching from Croatia through Serbia, Bulgaria, Romania, and into Ukraine and Russia.

The Black Sea has many bays, like Karkinit Bay in Ukraine and the Gulf of Burgas in Bulgaria.

Some islands belong to Bulgaria, Romania, Turkey, and Ukraine, including St. Anastasia Island and Zmiinyi (Snake) Island.

Geology and bathymetry

The Black Sea is split into two parts—the Western Black Sea and Eastern Black Sea—by a ridge called the Mid-Black Sea High. This ridge stretches south from the Crimean Peninsula. The sea has two old basins formed when an ancient volcanic arc split apart long ago.

Over time, the sea has changed shape and depth. The land around it has moved up and down, and there have been periods of volcanic activity. The sea’s floor has deep areas and steep edges, especially near Turkey and Georgia. The deepest part of the Black Sea is called the Euxine abyssal plain, reaching over 2,000 meters deep near the Crimean Peninsula.

Hydrology

The Black Sea is the world's largest body of water with a special kind of basin. In this basin, deep water doesn't mix with the top layers that get air from the sky. Because of this, over 90% of the deep water has no oxygen. The way water moves around the Black Sea is mostly shaped by the shape of the bottom and rivers that flow into it. This creates layers that don't mix easily, making it a special type of water body.

Water flows into the Black Sea from the Mediterranean Sea through the Dardanelles and Bosporus. This water is saltier and heavier, so it sinks to the bottom. Fresher water from the Black Sea flows out near the surface into the Sea of Marmara. Scientists found an underwater "river" of very salty water flowing along the bottom of the Black Sea from the Mediterranean. This discovery was made in 2010 by scientists at the University of Leeds and was the first of its kind ever found.

Hydrochemistry

The Black Sea has special water that does not let air mix deep down. This helps keep old things, like boat parts, in very good shape. Because of this, scientists and explorers love studying the Black Sea. They have found ancient shipwrecks in amazing condition, such as a Byzantine ship called Sinop D near the coast of Sinop, Turkey.

Sometimes, scientists think that if a big space rock hit the Black Sea, it could release harmful gases. There have also been rare reports of bright flashes during storms, maybe from lightning striking gases rising from deep below.

Ecology

The Black Sea has many plants and animals that live in its special mix of fresh water and salt water.

The sea is home to tiny plants called phytoplankton, like diatoms and cyanobacteria. These plants give energy to other creatures. Bigger animals, like fish and dolphins, also live here. Some animals, like the zebra mussel and common carp, are native to the area.

The Black Sea faces challenges from pollution and human activities, which have affected its plants and animals. Efforts to reduce pollution have helped the ecosystem in some places, but it still faces environmental pressures.

History

Mediterranean connection during the Holocene

The Black Sea connects to the World Ocean through two shallow straits, the Dardanelles and the Bosporus. During the last ice age, sea levels were much lower than today.

Some researchers think that the Black Sea was once a lake with much lower water levels after the ice age. Over time, water levels rose and connected with the Aegean Sea. There are different ideas about when and how this happened, including a theory called the "Black Sea deluge hypothesis".

Deluge hypothesis

The Black Sea deluge is an idea that around 5600 BC, water from the Mediterranean Sea suddenly rushed into the Black Sea through the Bosporus Strait. This idea was widely discussed after it was featured in The New York Times in 1996. While it is agreed that water levels rose, there is debate about how fast it happened and its effects.

Archaeology

Many ancient groups, such as the Hittites, Greeks, Romans, and Ottomans, sailed the Black Sea. The deep, still waters of the sea help preserve ancient ships and other objects, making it a popular area for marine archaeologists to explore.

Recorded history

The Black Sea was an important route for travel and trade in the ancient world, linking places like the Balkans, Caucasus, and Central Asia. The area at the eastern end of the sea, known as Colchis (in modern-day Georgia), was considered the edge of the known world by ancient Greeks.

Greek settlers began visiting the Black Sea around the 9th century BC, establishing colonies and creating a rich trade network. These colonies developed their own culture while staying connected to the larger Greek world.

Modern history

The Crimean War took place here between 1853 and 1856, with battles involving France, Britain, and Russia. After the war, Russia agreed to keep the Black Sea free from military ships.

World Wars

The Black Sea was important in both World War I and World War II. Strong defenses protected Soviet bases, making attacks very difficult.

21st century

In 2022, during the conflict in Ukraine, the Black Sea became a contested area. Russian and Ukrainian forces fought for control of islands and ships, and there were several notable naval battles and incidents.

Economy and politics

The Black Sea is very important for connecting Asia and Europe. People use it for many things, like moving goods by ship, fishing, looking for oil and natural gas under the water, and visiting beautiful beaches.

The sea helps ships move between Europe and Asia. Besides shipping and fishing, people also look for oil and gas under the sea. It is also a popular place for tourists to visit and relax.

Navigation

There are many ports along the Black Sea where ships can stop. Lots of big ships travel through the Black Sea every day.

Fishing

Fishermen in Turkey catch lots of fish each year, especially in the winter months.

Hydrocarbon exploration

The Black Sea has oil and natural gas, but people are still learning how much is there. They have made some discoveries, especially near Romania, but there is still more to find out.

Trans-sea cooperation

Urban areas

Tourism

See also: Romanian Black Sea resorts; Caucasian Riviera; Bulgarian Black Sea Coast; and Black Sea Region, Turkey

Since the end of a big political split, many people have started visiting the Black Sea for vacation. Resorts along the coast have become very popular.

The following is a list of notable Black Sea resort towns:

• 2 Mai (Romania)
• Agigea (Romania)
• Ahtopol (Bulgaria)
• Amasra (Turkey)
• Anaklia (Georgia)
• Anapa (Russia)
• Albena (Bulgaria)
• Alupka (Crimea, Ukraine/Russia (disputed))
• Alushta (Crimea, Ukraine/Russia (disputed))
• Balchik (Bulgaria)
• Batumi (Georgia)
• Burgas (Bulgaria)
• Byala (Bulgaria)
• Cap Aurora (Romania)
• Chakvi (Georgia)
• Constanța (Romania)
• Constantine and Helena (Bulgaria)
• Corbu (Romania)
• Costinești (Romania)
• Eforie (Romania)
• Emona (Bulgaria)
• Feodosia (Crimea, Ukraine/Russia (disputed))
• Foros (Crimea, Ukraine/Russia (disputed))
• Gagra (Abkhazia/Georgia)
• Gelendzhik (Russia)
• Giresun (Turkey)
• Golden Sands (Bulgaria)
• Gonio (Georgia)
• Gudauta and subsequently the Gudauta Bay (Abkhazia/Georgia)
• Gurzuf (Crimea, Ukraine/Russia (disputed))
• Hopa (Artvin, Turkey)
• Jupiter (Romania)
• Kamchia (Bulgaria)
• Kavarna (Bulgaria)
• Kiten (Bulgaria)
• Kobuleti (Georgia)
• Koktebel (Crimea, Ukraine/Russia (disputed))
• Lozenetz (Bulgaria)
• Mamaia (Romania)
• Mangalia (Romania)
• Năvodari (Romania)
• Neptun (Romania)
• Nesebar (Bulgaria)
• Novorossiysk (Russia)
• Obzor (Bulgaria)
• Odesa (Ukraine)
• Olimp (Romania)
• Ordu (Turkey)
• Pitsunda/Bichvinta (Abkhazia/Georgia)
• Pomorie (Bulgaria)
• Primorsko (Bulgaria)
• Rize (Turkey)
• Rusalka (Bulgaria)
• Samsun (Turkey)
• Saturn (Romania)
• Şile (Turkey)
• Sinop (Turkey)
• Skadovsk (Ukraine)
• Sochi (Russia)
• Sozopol (Bulgaria)
• Sudak (Crimea, Ukraine/Russia (disputed))
• Sulina (Romania)
• Sunny Beach (Bulgaria)
• Sveti Vlas (Bulgaria)
• Trabzon (Turkey)
• Tsikhisdziri (Georgia)
• Tuapse (Russia)
• Ureki (Georgia)
• Vama Veche (Romania)
• Varna (Bulgaria)
• Venus (Romania)
• Yalta (Crimea, Ukraine/Russia (disputed))
• Yevpatoria (Crimea, Ukraine/Russia (disputed))
• Zonguldak (Turkey)

Modern military use

The rules for ships passing between the Black Sea and the Mediterranean Sea are set by an agreement from 1936. Turkey controls these passages. Most ships can pass freely, but military ships have special rules.

The Russian navy has its main base in Sevastopol.

In late 2023, Russia announced plans to build a naval base on the Black Sea coast of Abkhazia.