Congo River
The Congo River, one of the most significant waterways in equatorial Africa, is the second-largest river in the world by flow volume and the longest in the Democratic Republic of the Congo (DRC), stretching 2,700 miles (4,344 kilometers). Known historically as a vital transportation and commerce route, the river's vast network of tributaries provides approximately 9,000 miles (14,500 kilometers) of navigable waterways. The Congo River is notable for crossing the equator twice and features a unique geography that includes waterfalls and rapids near its mouth, contributing to its status as one of the world's largest carbon sinks.
The river flows through a region rich in biodiversity, with the Congo Basin containing about one-sixth of the world's remaining tropical forests and hosting diverse wildlife, including critically endangered species such as forest elephants and several types of great apes. However, human activities such as deforestation, poaching, and industrial exploitation pose significant threats to the ecosystem. Among current initiatives is the ambitious Grand Inga Hydroelectric Project, aimed at harnessing the river's power, though it has raised environmental concerns regarding its impact on both local communities and the rainforest. Overall, the Congo River stands as a crucial resource for the region, intertwining ecological importance with human livelihoods and development challenges.
Subject Terms
Congo River
- Category: Inland Aquatic Biomes.
- Geographic Location: Africa.
- Summary: The Congo is the most important river in equatorial Africa and the second-largest worldwide in flow volume. For hundreds of years, it has been a key means of transportation and commerce, and more recently, it has held promise as a major source of hydroelectric power.
The Congo River, also known as the Zaire River, is the longest river in the Democratic Republic of the Congo (DRC), with a length of 2,700 miles (4,344 kilometers). It is the second-longest river in Africa (after the Nile), the sixth-longest river in the world, and the second-largest (after the Amazon) river in the world in terms of flow volume; it is also the only major river of the world to cross the equator; the Congo crosses it twice. The Congo and its tributaries include about 9,000 miles (14,500 kilometers) of navigable waterway. The Congo Plume, created where the Congo empties into the Atlantic Ocean, is one of the largest carbon sinks in the world.
Geography and Climate
The Congo Basin is one of the four primary geographic regions of the DRC, covering about one-third of the country's area. It covers more than 782,000 square miles (2 million square kilometers). It extends into six countries: Cameroon, the Central African Republic, the DRC, Equatorial Guinea, Gabon, and the Republic of Congo. The Congo Basin lies about 2,000 to 2,600 feet (600 to 800 meters) above sea level, while the surrounding land is relatively even and flat and sits about 1,600 feet (500 meters) above sea level.
The Congo River flows consistently throughout the year because it is so long and crosses so much north-south territory. When the dry season is in one part of the river, it is the rainy season in another. This ecoregion's climate is tropical and very wet, especially near the equator. The average annual rainfall is approximately 75 inches (190 centimeters), and the average annual temperature is 75 degrees F (24 degrees C).
The geography of the Congo River is unusual in that it has waterfalls and rapids near its mouth; from Malebo Pool to the Atlantic, the Congo has 32 cataracts (known collectively as Livingstone Falls) and drops a total of about 980 feet (300 meters). The Congo forms an estuary at Matadi, a port city—and one of the largest harbors in central Africa—about 93 miles (150 kilometers) from the Atlantic coastline, and from this point onward, it is navigable by ocean-going ships. A canyon on the ocean floor continues the river's course for about 500 miles (800 kilometers) into the ocean.
Wildlife
The Congo Basin is a highly diverse ecological region and is the world's second-largest expanse of tropical forest; about one-sixth of the world's total remaining tropical forest is in this region. The basin is estimated to harbor well over 11,000 plant species. Plant types in the endemic biome or found nowhere else on Earth include many species of the spiny, perennial herb family Caesalpiniaceae and the family of okoumé trees (Burseraceae spp.). Meadow habitats feature barnyard grass (Echinochloa spp.), papyrus (Cyperus papyrus), and other sedge types (Cyperaceae spp.).
About 400 mammal species, almost 1,000 bird species, about 80 species of amphibians, and nearly 400 reptile species live in the Congo Basin. The region is home to most of Africa's remaining great apes and forest elephants. The critically endangered western lowland gorilla and eastern lowland gorilla, as well as the extinction-threatened Cross River gorilla and mountain gorilla, are among the primate species most in focus of conservation efforts here. Among the threats to ward off are poaching for bushmeat and habitat destruction from human conflict and commercial interests.
Researchers believe that up to 700 species of fish live in this river; as many as 80 percent are endemic. Among the most commonly found are the generally nocturnal, somewhat electrified elephantfish (Mormyridae spp.) and the cichlids (Cichlidae spp.), remarkable among fishes for their extended care of offspring. Also found in the Congo are African lungfish (Protopteridae spp.), which can survive dry seasons by burrowing into the mud, covering themselves in mucus, and obtaining oxygen by direct breathing from the air.
Along with fish, many reptiles inhabit the waters and shores of the Congo River. Some include crocodiles, semiaquatic tortoises, geckos, skinks, lizards, and several species of water snakes. The slender-snouted crocodile (Mecistops cataphractus), which lives in the Congo basin, is one of many reptiles in the area that is listed as endangered. Less than 1,000 of these crocodiles are found in the wild, and their population continues to face hunter threats and habitat loss.
Human Impact
The Congo has been a major source of transportation and commerce in equatorial Africa for centuries and remains so today as roads and railroads remain relatively sparse in the region. Notably, European exploration and colonization of the area were initially inhibited by the presence of cataracts near the mouth of the river. Today, railroads have been constructed to bypass major cataracts (replacing the human porters used in previous centuries). With its tributaries, the Congo forms a system of thousands of miles of navigable waterways, with goods and people transported by gasoline-powered barges and ships and more traditional vessels.
The primary threats to the ecology of the Congo Basin stem from expanding human populations and increased exploitation of the region's substantial natural resources. Much of the region's forests are contracted to logging companies. Deforestation rates in the basin have risen in the twenty-first century. According to data from Global Forest Watch, an app supported by the World Resources Institute, the Democratic Republic of Congo lost the second-largest area of tropical forestland on Earth in 2018. Only Brazil lost more forest land. Estimates from research by the University of Maryland have found that the DRC’s forestland could be entirely gone by 2100 if logging continues at the current pace. The country has attempted to protect areas by creating several national parks, wildlife preserves, and transboundary complexes. The Congo Basin boasts nine world heritage sites. Four of those sites have been placed on the list of World Heritage Sites in danger. UNESCO is working with the Congo to protect the areas. Two programs, developed in 2000, take action to preserve sites: Biodiversity Conservation in Regions of Armed Conflict: Protecting World Heritage and Central Africa World Heritage Forest Initiative (CAWHFI).
Slash and burn agriculture is another source of deforestation. As the population expands, so will the need for new agricultural lands. Traditional and commercial fishing practices have rapidly expanded, particularly in the coastal regions. Other abundant and often exploited natural resources in the Congo River Basin include petroleum, diamonds, gold, coltan, and ivory; the latter is driving the rapid depletion of the elephant and hippo populations through poaching. The spread of logging and other extraction industries into previously remote areas brings new workers and roads and is a primary cause of biodiversity loss. Presently, the commercial bushmeat trade is the leading cause of wildlife loss. Animals such as monkeys, bonobos, and antelope fall prey to this lucrative business.
During the 1970s and 1980s, the DRC built two hydroelectric dams (Inga I and Inga II) on the Inga Falls on the lower Congo River, about 30 miles (50 kilometers) upstream from the river's mouth. Although the dams are constructed in an excellent location due to the significant drop and water flow over the falls, they have been much less successful than expected and operate far below their capacity. In the 2010s, several international firms began work on a proposed series of six hydroelectric dams known as the Grand Inga Hydroelectric Project. When completed, the $80 billion project would be the world’s largest hydroelectric plant. It would generate over 40,000 megawatts of electricity, about twice as much as the Three Gorges Dam in China, the world’s largest as of 2024.
This new dam would constitute the largest hydroelectric project in the world, with 52 generators potentially producing over twice as much electricity as the Three Gorges Dam project in China. However, some international organizations oppose the new project because it will change the river's oceanic plume, require the flooding of large regions of farmland, and require the destruction of large swaths of the rainforest to run power transmission lines. Some organizations also point to ongoing problems with corruption in the DRC and the lack of compensation provided to those displaced by constructing the first two dams.
Though hydroelectric power may reduce fossil fuel use, forest loss and degradation within the basin are likely to contribute to some global climate change. Deforestation releases more carbon into the atmosphere than any other land-use practice on the continent.
Bibliography
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