Seas Around the Globe

What Are the 7 Seas Around the Globe ?

Andaman Sea –

Area: 308,000 sq. mi, 797,700 sq. km Average Depth: 2,854 ft., 870 m. Greatest Known Depth: Off Car Nicobar Island - 12,392 ft., 3,777 m.

The Andaman Sea is known as a marginal sea, meaning a body of water that is contained within or bounded by an ocean. It is found in the northeastern portion of the Indian Ocean, between the Andaman Islands and the west coast of Myanmar and Malaysia. The Andaman seabed is at the boundary of two tectonic plates and therefore experiences regular tectonic activity.

Its habitat is dominated by seagrass meadows and mangrove forests which provide shelter to many endangered species, including multiple species of sea turtle. The habitats also make it a bountiful area for fishing with Thailand deriving 19% of its yearly harvests from the Andaman. The other major economic use is tourism, with the Nicobar Islands home to rich coral reefs, some of which are candidates for UNESCO World Heritage Site status.

Arabian Sea –

Area: 1,491,000 sq. mi, 3,862,000 sq. km Average Depth: 8,970 ft., 2,734m. Greatest Known Depth: Wheatley Point — 15,262 ft., 4,652 m.

The Arabian Sea sits in the northwest of the Indian Ocean, in a pocket below Pakistan and Oman and to the west of India. It is connected to both the Persian Gulf and the Red Sea, providing a bridge between the Arabian Peninsula and the ocean at large. In ancient times, the Greeks referred to the area as the Erythraean Sea.

Due to its proximity to major oil exporting nations and the Suez Canal, the Arabian Sea is part of the busiest shipping lanes in the world and the busiest ports like Salalah in Oman. Major cities on the coast include Mumbai, Muscat, Abu Dhabi, and Dubai. The tiny island of Zalzala Koh was formed in 2013 after an earthquake but had entirely submerged beneath the sea by 2016.

Aral Sea –

Area: 6,626 sq. mi, 17,160 sq. km Average Depth: 29 ft., 8.7 m. Greatest Known Depth: Exact location unknown — 138 ft., 42 m.

The Aral Sea is an entirely landlocked body of water and used to be the fourth-largest lake in the world. It is split in two by the border between Kazakhstan and Uzbekistan, with a drainage basin that encompasses Turkmenistan, Kyrgyzstan, Tajikistan, and Afghanistan. It has become one of the most renowned examples of environmental degradation after its surface area reduced from 68,000 km2 in 1960, to what remains today as two much smaller separate lakes: the North and South Aral Seas.

Soviet infrastructure projects in the mid-20th century diverted the major tributaries away from the Aral, leading to a reduction to 10% of its original size. At its lowest point, the Aral was made up of just two relatively small lakes, with the southeastern portion redesignated as the Aralkum Desert. Since 2014, there has been evidence to show that replenishment of the lake's volume is working, with rising volume levels in the North Aral and the center.

The Sea naturally has low levels of biodiversity but still a large number of unique, endemic species, many of which were lost when the Sea receded. However, rising water levels have reduced the salinity of the Aral Sea, which has paved the way for a recovery in native fish species.

Baltic Sea –

Area: 163,000 sq. mi, 422,200 sq. km Average Depth: 180 ft., 55 m. Greatest Known Depth: Landsort Deep — 1,380 ft., 421 m.

As one of the most enclosed seas that are still openly connected to the world ocean, the Baltic is vitally important to a variety of its surrounding countries. It is bound by Denmark, Germany, Poland, Latvia, Lithuania, Estonia, Russia, Finland, and Sweden. Historically, Denmark served as the geographical and literal gatekeeper of the Baltic Sea due to the narrow entrance channels upon which its islands are situated. Up until 1857, Denmark charged a toll for any ships passing through the channels to enter the Baltic which amounted to a third of the country's yearly income.

The Baltic remains a major feature of European geopolitics. The Nord Stream gas pipeline from Russia runs beneath the sea and is a political leverage point over Western Europe. A second pipeline has been built along the same route, but the war in Ukraine and the resulting worsening of international relations have halted the project. The Baltic would also become crucial to any larger-scale military operations as major seaports for Russia, Germany, and Scandinavia lie on its shores.

Bering Sea and Strait –

Area: 884,900 sq. mi, 2,291,900 sq. km Average Depth: 5,075 ft., 1,547 m. Greatest Known Depth: Bower's Basin — 15,659 ft., 4,773 m.

The Bering Sea and Strait separate Russia from the USA and more expansively, Eurasia from North America. During the most recent ice age, scientists believe that sea levels were low enough in the Bering Strait for a land bridge to form. Humans and other large mammals would have migrated from Eurasia to North America across the dried strait.

Home to the largest submarine canyon in the world, the Zemchug Canyon, the Bering Strait has a vibrant ecosystem thanks to favorable currents and nutrient upwelling. Fish biodiversity is high and this supports a large number of seabird species that rely on the Bering for fertile breeding grounds. It also provides both Russia and the USA with valuable fisheries, worth $600 billion and $1 billion respectively.

The sea is named after Vitus Bering, a Danish explorer who became the first to explore the area by sailing from the North Pacific Ocean to the Arctic. Geopolitically, the Bering is important because it presents the smallest distance between Russia and the USA and a point of possible conflict over fishing rights.

Black Sea –

Area: 168,500 sq. mi, 436,402 sq. km Average Depth: 4,111 ft., 1,253 m. Greatest Known Depth: Euxine Abyssal Plain — 7,257 ft., 2,212 m.

The Black Sea sits in the middle of various geographic zones, with Europe to the north and west, the Caucasus in the east, and Turkey in the south. Historically, the Black Sea was central to the wealth of the Hanseatic League, a prosperous medieval economic alliance. Today, the Black Sea remains important for geopolitical reasons. Russia has tried to increase its control over the area recently and headquarters its Black Sea Fleet in Sevastopol after it annexed Crimea from Ukraine in 2014. During Russia's invasion of Ukraine in 2022, the Black Sea was a key route of attack and the Russians used their fleet to blockade grain exports from Ukraine.

It is the largest expanse of brackish water in the world which supports a unique ecosystem of animals that thrive in these specific conditions. The large number of rivers that drain into the Black Sea also deposit high volumes of nutrient-rich sediment to support good levels of phytoplankton. Rapid industrial expansion throughout the 20th century saw increased levels of pollution which negatively affected the ecology of the Black Sea, although regulation brought in over the millennium has allowed the ecosystem to recover.

Caribbean Sea –

Area: 1,063,000 sq. mi, 2,754,000 sq.km Average Depth: 7,217 ft., 2,200m. Greatest Known Depth: Puerto Rico Trench - 25,217 ft., 7,686 m.

The Caribbean Sea is defined by a series of Caribbean islands to the north and east, Central America to the west, and South America to the south. The average climate is tropical and hurricanes are common in a season that stretches from June to November. Trade wins create a northerly current and a consequential upwelling of nutrients near the Yucatan, leading to bountiful fish stocks. However, the main economic function of the Caribbean is tourism. The warm waters, coral reefs, and sandy beaches mean it is an attractive destination.

Christopher Columbus was the first European to explore the Caribbean and founded colonies in modern-day Haiti/Dominican Republic. Further exploration in the 18th and 19^th centuries led to a developing level of scientific interest. The area is home to 9% of the world's coral reefs which are vital to both environmental diversity and the area's attraction to tourists. However, up to 95% of the reefs have experienced some form of coral bleaching due to rising temperatures in the Caribbean. The modern-day Caribbean presents a paradox for local countries: while the ecosystem attracts human activity that is crucial to the economy, it also acts as the main source of environmental degradation.