Top 10 Largest Aquatic Ecosystems

Spanning over 7 million square kilometers (2.7 million sq mi), the Amazon River Basin is the largest aquatic ecosystem in the world, accounting for about 40% of the Earth's fresh water. Located in South America, it flows through Brazil, Colombia, and Peru, and is home to an incredible array of plant and animal species. The basin's vast size also supports approximately 200 million people living along its banks. Historically, the Amazon River played a vital role in the indigenous cultures and civilizations that once thrived within its waters. This ecosystem is considered one of the most biodiverse on the planet due to its unique geography and climate. The Amazon River Basin also faces significant threats from deforestation, logging, and pollution, making conservation efforts crucial for its preservation.

Covering about 23% of North America's freshwater surface, the Great Lakes ecosystem is the largest group of lakes on Earth, comprising four major lakes (Lake Superior, Lake Michigan, Lake Huron, and Lake Erie) and one smaller lake (Lake Ontario). The ecosystem supports a diverse range of aquatic life, including fish, amphibians, and birds. Approximately 60 million people rely on the Great Lakes for drinking water, fishing, and recreation. The region's complex geology has created numerous islands, peninsulas, and bays, which have formed over thousands of years. This ecosystem is also a vital component of the North American food chain, supporting commercial fisheries that generate billions of dollars in revenue each year.

As the world's largest inland body of water, covering approximately 371,000 square kilometers (143,200 sq mi), the Caspian Sea ecosystem is an essential component of regional climate regulation and supports a unique array of aquatic life. The region has been home to several ancient civilizations, including the Persian Empire and the Soviet Union. Approximately 30 million people rely on the Caspian Sea for fishing, aquaculture, and tourism. This ecosystem also plays host to several important shipping lanes, including those connecting Europe and Asia.

Located in southern Siberia, Russia, Lake Baikal is the world's largest and oldest freshwater lake, spanning approximately 31,722 square kilometers (12,274 sq mi). The lake holds about 20% of the world's unfrozen freshwater and supports an incredible array of unique aquatic life. Approximately 1 million people rely on the lake for fishing, drinking water, and recreation. Historically, the region was home to numerous indigenous tribes that inhabited the shores and islands surrounding the lake.

Covering approximately 10% of Europe's landmass and accounting for about 88% of its fresh water supply, the Danube River Basin is one of the most significant aquatic ecosystems in Western Europe. Spanning across several countries including Germany, Austria, Slovakia, Hungary, Croatia, Serbia, Bulgaria, Romania, and Moldova, it flows approximately 2,860 kilometers (1,778 mi) through central and southern Europe. Approximately 150 million people rely on the Danube for drinking water, fishing, and navigation. The region's rich history has influenced the development of numerous cultures and civilizations.

Spanning across India, Bangladesh, Nepal, Bhutan, and Myanmar, the Ganges-Brahmaputra Delta is one of the largest freshwater delta ecosystems in the world, covering approximately 250,000 square kilometers (96,500 sq mi). The region supports an incredible array of aquatic life, including numerous fish species and mangrove forests. Approximately 550 million people rely on the Ganges and Brahmaputra rivers for drinking water, fishing, and livelihoods.

Located in Southeast Asia, spanning across Cambodia, Vietnam, Laos, Thailand, and Myanmar, the Mekong River Delta is one of the largest freshwater delta ecosystems in the world, covering approximately 139,000 square kilometers (53,800 sq mi). The region supports a diverse array of aquatic life, including fish, dolphins, and numerous bird species. Approximately 60 million people rely on the Mekong for drinking water, fishing, and livelihoods.

Covering approximately 68,870 square kilometers (26,600 sq mi) in Africa, Lake Victoria is the largest freshwater lake south of the Sahara Desert, supporting an array of aquatic life including numerous fish species and other organisms. Approximately 40 million people rely on the lake for drinking water, fishing, and livelihoods.

Spanning across Russia's Far Eastern region and China's northeastern province, Heilongjiang Province, the Amur River Basin is one of the largest freshwater ecosystems in East Asia, covering approximately 746,000 square kilometers (288,000 sq mi). The region supports an array of aquatic life, including numerous fish species, amphibians, and birds. Approximately 25 million people rely on the Amur for drinking water, fishing, and livelihoods.

Located between China and Korea, the Yellow Sea is one of the largest inland seas in the world, covering approximately 375,000 square kilometers (145,000 sq mi). The region supports an array of aquatic life, including numerous fish species, seaweed, and other organisms. Approximately 20 million people rely on the Yellow Sea for drinking water, fishing, and livelihoods.