Category Rivers

Why is the Ganges delta unique?

Known as the Sundarbans Delta or the Bengal Delta, the delta of the river Ganges is the world’s largest river delta. By definition, deltas are wetlands that are formed by the rivers as they empty their water and sediments into oceans, lakes, or other water bodies. The Sundarbans Delta encompasses more than 105,000 square kilometres and covers West Bengal and Bangladesh. This delta is formed when the combined waters of several river systems that include the Brahmaputra and the Ganges rivers, empty into the Bay of Bengal. Because of its rich soil, it is also one of the most fertile regions in the world, and is called the Green Delta. It begins at the Meghna River and stretches till the Hooghly River.

The biodiversity of the Ganges delta is also very vast. It is covered with deciduous forests and mangroves and is home to the famous Bengal Tiger. Sundarbans, which forms a major part of this delta, is the world’s largest mangrove forest and has a wide variety of wildlife such as the Indian python, elephants, and crocodiles. One can also find exotic birds like kingfishers, eagles, and woodpeckers here. It is also one of the world’s most populated regions, with approximately 130 million inhabitants.

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The river as a dumpyard

The Mekong is one of the longest rivers in the world, cutting across several Asian regions from Tibet and China to Thailand and Cambodia. But spanning a large area means the threats it faces are just as huge. What are they? Come, let’s find out.

Waste generated in any region is disposed of in many ways, including being dumped at landfills. (Only a minuscule fragment of waste is recycled globally.) Some countries export their waste. Several Asian countries have been taking in plastic waste from such countries, without really being equipped to handle waste disposal safely. In addition, these Asian countries have their own waste to deal with. The waste in landfills reach rivers and oceans through winds, rains, and drains. One such river is the Mekong. Painfully, three “of the worst six plastic polluting countries China, – Thailand, and Vietnam – have a presence in Mekong”, meaning the quantum of waste this river takes in is huge and increasing. The pandemic, with its masks, plastic sanitiser containers, take-away plastic boxes, etc., has exacerbated the situation. And, this is of grave concern.

The Mekong is a treasure trove of biodiversity – several species of plants, birds, reptiles, and fishes call the river and its surrounding regions home. But in the current scenario, rubbish is finding its way into the water, endangering wildlife. Animals and birds are in danger of being affected by plastic debris through entanglement or ingestion. There have been instances of dead whales “turning up in Thailand and Indonesia with many kilograms of plastics in their stomachs”. It is not just wildlife that’s affected. When humans consume creatures such as fish, we end up consuming plastic, which has the potential to cause serious health problems such as cancer. Since rivers drain into larger waterbodies such as seas (the Mekong mixes with the South China Sea) and oceans, the pollution they carry is transferred too.

An increase in the pollution of waterbodies is an indication of increasing pollution on land. And a grim reminder that unless we change our lifestyles to make this planet greener, we are likely to face the negative consequences of our own actions.

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What is harmful algal bloom?

Recently, Lake Merrit in Oakland, California, the U.S… turned reddish brown, causing fear among the residents. They were advised to not use the water and to keep their pets away from the water body. Scientists suspected a possible case of Harmful Algal Bloom (HAB), and the samples have been sent for investigation. This is not the first time that HAB has been experienced in the lakes in the US. In the last few months, there has been a sporadic rise in the detection of algal bloom in the lakes. Lakes such as Hopatcong, Anna, Erie, and so on have been witnessing the highest concentration of HAB, triggering concerns.

Algal bloom is an overgrowth of algae or algae-like bacteria in fresh, salt, or brackish waters. They can occur in a variety of colours, namely red, blue-green, brown, and pink. Depending on the algae, they can lead to the formation of scum, foam, froth, or a slick. Not all algal blooms are toxic. A HAB, though, is, and can endanger humans and many organisms.

What causes HAB?

Most are caused by cyanobacteria. Though they are bacteria, they perform photosynthesis just like algae, and are often called blue-green algae. Some produce dangerous cyanotoxins. The most reported cyanobacteria is microcystis. HAB Occurs naturally as well as due to human activities. In fact, human activities such as the burning of fossil fuels, land development, and deforestation have all led to an increase in the amount of carbon dioxide. The cyanobacteria feed on the carbon dioxide, which fuels their growth.

Most harmful algal blooms are caused by cyanobacteria. Though they are bacteria, they perform photosynthesis just like algae, and are often called blue-green algae.

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WHAT IS PELAGIC ZONE?

The pelagic zone is the open region of any lake, sea, or ocean that is away from any part of land, be it the coast or the sea floor. Marine life-from microscopic plankton and tuna to sharks – dominates this area. Due to the abundance of marine creatures, it is a critical space for producing oxygen, regulating climate, and economic activity.

Pelagic Zone Facts

The pelagic zone plays many critical roles that make it essential to life on Earth. Factors that make the pelagic zone unique include:

It covers more than 50% of the Earth in water, more than 3.2 kilometers (2 miles) deep.
It makes up more than 99% of the inhabitable space on our planet.
The deepest part of the ocean, the Mariana Trench, is about 11,000 meters (7 miles) deep.
The open ocean produces more than 50% of the world’s oxygen.
It is a critical carbon sink, storing 50 times more carbon dioxide than the atmosphere.
Many of its inhabitants never experience sunlight.

The open ocean provides food, medicine, and economic opportunities for people worldwide. In addition to seafood, ocean harvests provide ingredients for foods like peanut butter and soy milk. Medications for Alzheimer’s disease, cancer, heart disease, and arthritis use materials extracted from the ocean, and the United States alone produces $282 billion in ocean-dependent goods and services.

Layers of the Pelagic Zone

The pelagic realm is divided into five distinct regions based on average depth and sunlight availability. Moving from the surface to the ocean floor, the zones are labeled:

Epipelagic
Mesopelagic
Bathypelagic
Abyssopelagic
Hadopelagic

Sunlight, oxygen, and temperature decrease with depth while pressure increases. The organisms in each zone have adapted to live in these conditions.

Credit : Study.com

Pucture Credit : Google 

WHAT IS MR. TRASH WHEEL DEVICE?

Mr. Trash Wheel, officially called the Inner Harbor Water Wheel, is a trash interceptor, a vessel that removes trash from the Jones Falls river as it empties into the Inner Harbor in Baltimore, Maryland. It is powered by water wheels and solar cells, and places trash from the harbor onto an onboard conveyor belt which routes it into dumpsters on the vessel. Mr. Trash Wheel was invented by John Kellett in 2008, who launched a pilot vessel at that time. A larger vessel was later developed; it replaced the pilot vessel and was launched in May 2014. The Mr. Trash Wheel vessel is part of the Waterfront Partnership of the City of Baltimore’s “Healthy Harbor Plan.”

Mr. Trash Wheel is a moored vessel that removes trash from the mouth of the Jones Falls river at Baltimore’s Inner Harbor. Rubbish from the streets of Baltimore is flushed into storm drains that empty into the Jones Falls river. The floating rubbish is then carried by the river to its outlet into the Inner Harbor, where it is captured by Mr. Trash Wheel. Mr. Trash Wheel is powered by the current from the river, and backup power is provided by solar panels when the current is sluggish. These power a conveyor belt. Mr. Trash Wheel removes flo

ating debris using rotating forks that dip into and out of the water, and which then place the trash onto a conveyor belt which moves it into a dumpster. The water wheel can be controlled remotely on the Internet. Mr. Trash Wheel was constructed using $720,000 of public and private funding.

Credit : Wikipedia

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HOW DID THE AMAZON RIVER GET ITS NAME?

The Spanish soldiers who explored the region for the first time in 1541 battled native female warriors who fought bravely. The name the invaders gave to the river came from the Persian hamazan, meaning ‘those who fight together’ – also used in Greek mythology for outstanding women warriors.

Before the conquest of South America, the Rio Amazonas had no general name; instead, indigenous peoples had names for the sections of the river they occupied, such as Paranaguazu, Guyerma, Solimões, and others.

In the year 1500, Vicente Yañez Pinzon, in command of a Spanish expedition, became the first European to explore the river, exploring its mouth when he discovered that the ocean off the shore was freshwater. Pinzon called the river the Rio Santa Maria de la Mar Dulce, which soon became abbreviated to Mar Dulce, and for some years, after 1502, it was known as the Rio Grande.

Pinzon’s companions called the river El Río Marañón. The word Marañón is thought by some to be of indigenous origin. This idea was first stated in a letter from Peter Martyr to Lope Hurtado de Mendoza in 1513. However, the word may also be derived from the Spanish word maraña; meaning a tangle, a snarl, which well represents the bewildering difficulties that the earlier explorers met in navigating not only the entrance to the Amazon, but the whole island-bordered, river-cut, and indented coast of what is now the Brazilian state of Maranhão.

The name Amazon arises from a battle that Francisco de Orellana had with a tribe of Tapuyas where the women of the tribe fought alongside the men, as was the custom among the entire tribe. Orellana derived the name Amazonas from the ancient Amazons of Asia and Africa described by Herodotus and Diodorus.

Credit: New World Encyclopedia

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