Озеро Маракайбо: История, География и Экология

Body of water in Venezuela

Lake Maracaibo (lang es) is a brackish lake located in northwestern Venezuela, between the states of Zulia, Trujillo, and Mérida. Hydrologically, it is a semi enclosed bay off the coast of the Gulf of Venezuela. Lake Maracaibo is commonly considered a lake, though due to its current geological characteristics, it should not be considered as such. With a surface area of , it is the largest lake in South America and one of the oldest on Earth, having formed disputably as a lake 36 million years ago in the Andes Mountains. The lake is connected to the Gulf of Venezuela to the north by a narrow spit. It is fed by numerous rivers, the biggest being the Catatumbo River. The fault in the northern section has collapsed and is rich in oil and gas resources. It is Venezuela's main oil producing area and an important fishing and agricultural producing area. Eutrophication caused by oil pollution is a major environmental problem facing the lagoon. The area around the lagoon is inhabited by a quarter of the country's population and is also the place with the most frequent lightning on earth. The famous Catatumbo lightning can illuminate nighttime navigation.

Lake Maracaibo is located within the eponymous basin and is one of the oldest lakes on earth. It was formed 36 million years ago when the faults collapsed when the Andes were uplifted in the late Eocene. and the lighter fresh water floated on the heavier salt water, causing nutrients to be deposited on the bottom of the lake, resulting in the accumulation of more than a five kilometer thick deposit of sediment on the bedrock. The lake is in the shape of a vase. It is 210 kilometers long from north to south, 121 kilometers wide from east to west, covers an area of 13,512 square kilometers, the deepest is 35 meters, the shore length is about 1000 kilometers, and the volume is about 280 cubic kilometers. There are also the Santa Ana River, Chama River, Motatán River, Escalante River, and about fifty other rivers which drain into it. The nocturnal thunderstorms occur on average about 297 days per year. At its peak in September, the lake area can experience up to 280 lightning strikes per hour,

The aboriginal Pueblo añú people who lived on the banks of the lake refer to it as Coquivacoa. The tribes of Wayuu, Caquetíos, and Quiriquires also lived in the area. When Italian navigator Amerigo Vespucci and Spanish explorer Alonso de Ojeda's fleet sailed here on August 24, 1499 (the first time Europeans entered this area), the stilt houses in which the Añú lived in reminded Vespucci of the Italian city of Venice, so he named the region Veneziola (Venezuela in Spanish), or "Little Venice". Spain made two attempts to establish settlements around the lake in 1529 and 1569, but it was not until 1574 that the city of Maracaibo was successfully established. On July 24, 1823, Venezuela won the famous Battle of Lake Maracaibo on the lake during the Venezuelan War of Independence. The original depth of the lake mouth, which was only more than 4 meters deep, was increased to 8 meters after dredging in the 1930s, and the 3 kilometer long stone breakwater was further increased to 11 meters after its completion in 1957, allowing ocean going tankers to enter the lake, The 8,678 meter General Rafael Urdaneta Bridge over the lake connecting Maracaibo and Santa Rita was completed in 1962. the first oil well was constructed in 1917, and large scale exploitation began in 1922.

Lake Maracaibo possesses highly oxygenated waters which makes it rich in algae, and in turn fishes, making it very biologically diverse. It is home to clams, blue crabs, shrimps and other aquatic products, including many endemic species such as the Maracaibo half hooked catfish (Hypostomus maracaiboensis), the Maracaibo hairy catfish (Trichomycterus maracaiboensis), the Maracaibo Lake Lamont catfish (Lamontichthys maracaibero), Lake Maracaibo tetra (Bryconamericus motatanensis), and Maracaibo wolf anchovies (Lycengraulis limnichthys) living in surface waters. The lake has been drilled about 14,000 times, and more than 15,000 miles of oil and gas pipelines criss cross the lake floor, but most of these pipelines are half a century old, with oil leaking from many aging underwater pipes.

In lakeside towns such as the city of Maracaibo, the lake water is contaminated with E. coli from feces, oil pollution, and eutrophication caused by agricultural sewage discharged into the lake, as well as domestic and industrial wastewater, resulting in the blooms of duckweed and green algae. The presence of large amounts of duckweed blocks the passage of sunlight, significantly affecting biological cycles, preventing the development of native algae and plant species. Additionally, duckweed residues accumulate at the bottom, generating a layer of organic elements that produces large amounts of ammonium, methane and other compounds whose saturation causes eutrophication of the waters. In the spring of 2004, heavy rains fell in the Lake Maracaibo basin, causing a large influx of fresh water into the lake. This caused nutrients originally deposited on the bottom of the lake to float to the surface of the lake, which in turn allowed the duckweed to rapidly multiply and triggered a bloom that lasted for up to eight months. The blooms were noted in June to have covered 18% of the lake, and the local government had to begin spending about $2 million per month on cleanup work. Within the existing polluting activities, the mining of mineral coal has started more recently, which further contaminates the basin with pollutants. Likewise, the so called cañadas, which are random drainage courses, drag large amounts of garbage from the human settlements that are in their path to the lake. In addition to this, residential waste such as plastic bags and bottles are also added. These pollutants all eventually get carried into the lake.

The long General Rafael Urdaneta Bridge connects the western and eastern coast of the lake together. It held the record for being the longest cable stayed concrete bridge in the world at the time of its inauguration in 1962. Located in the southern part of the Strait of Maracaibo, it is a vehicles only bridge that accommodates both directions of traffic, while its height allows for the passage of vessels up to 45 meters in height.