Category Environment

What happened in the Fukushima disaster?

The earthquake and tsunami that hit northeastern Japan on March 11, 2011, turned out to be more than just a natural disaster. It caused a nuclear accident at the Fukushima Daiichi power plant in Fukushima prefecture, north of Japan. Several reactors at the plant were damaged, raising concerns over radiation leaks. The government set up a 30-km no-fly zone around the facility, and 20 km around the plant were evacuated. Later, the evacuation area was further increased when a spike in levels of radiation was evident in local food and water supplies. Several thousand residents left their homes even as radiation levels remained high months later. About nine years after the worst nuclear disaster since Chernobyl occurred, the site is cleared of immediate danger, but it still has a lot of clearing up to do.

 

Picture Credit : Google

What is the purpose of National Green Tribunal?

Established a year earlier under the National Green Tribunal Act 2010, the National Green Tribunal began functioning in July 2011. This specialized body is “equipped with the necessary expertise to handle environmental disputes involving multi-disciplinary issues’ and is guided by principles of natural justice. It has aimed at disposing of causes related to forest, environment, biodiversity, air and water. While the principal bench function s from New Delhi, the zonal benches function from Bhopal, Pune, Kolkata and Chennai. The setting up of the tribunal was seen a huge step towards realizing environmental democracy. Hundreds of appeals/petitions are heard and judgments delivered every year. For instance, over 500 judgments were delivered by the tribunal in 2016, in cases relating to pollution, conservation, industry operations, thermal power plants, mining operations, and environmental compensation, among others.

 

Picture Credit : Google

When the International Year of Biodiversity was declared?

The United Nations (the U.N.) declared 2010 the International Year of Biodiversity. Throughout the year, several key initiatives were organized to spread awareness on the need to promote biodiversity conversation and encourage everyone – as individuals and groups – worldwide to take mindful steps to stop the loss of biodiversity. That year, the U.N.’s Convention on Biological Diversity held its 10th biannual meeting in Nagoya, Japan. This international legally binding treaty, which came into force in 1993, aims to encourage actions that will lead to a sustainable future.

Biodiversity — the variety of all life forms, from genes up — is vital because diversity makes for healthy, stable ecosystems. From coral reefs to the Kalahari, these natural ‘balancing acts’ are intrinsically valuable. But beyond beauty and amenity, ecosystems also provide essential ‘services’ such as breathable air, clean water and fertile soils. Fisheries, agriculture, medicine and many traditions and ways of life all depend on biodiverse ecosystems.

Clearly, biodiversity is key not just to life on Earth, but to economies and cultures. And for the poor, who often depend directly on land and sea for subsistence, it is literally a lifeline.

 

Picture Credit : Google

Which is considered to be the largest marine oil spill?

Also called the Gulf of Mexico oil spill, Deepwater Horizon oil spill is considered to be the largest marine oil spill in history. It occurred on April 20, 2010 when the Deep Horizon oil rig exploded in the Gulf of Mexico and off the coast of Louisiana, the U.S. The rig was leased by London-based oil company BP. By the time the leak from the exploratory well was capped 87 days later, more than three million barrels of oil had leaked into the waters while the explosion itself had claimed 11 lives. The disaster has had environmental, health and economic impacts.

An estimated 53,000 barrels were flowing into the Gulf of Mexico every day.

The accident also made extensive damages to the marine environment. According to the Centre for Biological Diversity, the oil spill killed over 82,000 birds, 25,900 marine mammals, 6,000 sea turtles and tens of thousands of fish, among others.

 

Picture Credit : Google

What are the effects of Hypoxia?

  • While fish and mobile invertebrates such as shrimp and crabs migrate out of hypoxic areas, slow-moving, bottom-dwelling creatures such as clams and oysters die after extended exposure.
  • It has also been found that fish that flee the potential suffocation may quickly become unconscious and die.
  • It was found in a study that low oxygen levels recorded along the Gulf Coast of North America led to reproductive problems in fish involving decreased size of organs, low egg counts and lack of spawning.
  • Alteration in marine ecosystem also has socio-economic impact on humans. It affects people whose livelihood depends on fishing.

 

Picture Credit : Google

How Dead Zone formed?

Dead ones generally occur near areas where heavy agricultural and industrial activity spill nutrients into the water. The excess nutrients, especially nitrogen and phosphorous, cause the rapid growth of microscopic algae called phytoplanktons. This phenomenon is called the nutrients, grow, die and sink to the bottom, where they are decomposed by bacteria. The bacteria inhale the dissolved oxygen in the water as they decompose the phytoplankton. This leads to the depletion of oxygen available to other marine life.

If the phytoplanktons are cyanobacteria, the problem is further intensified they are not consumed by zooplankton and fish. Hence they accumulate in water, leading to the expansion of dead zones. The bacterial degradation of their biomass consumes more oxygen in the water.

While nutrients run-off has been known for decades, researchers say that climate change is making the lack of oxygen worse. As more carbon dioxide is released enhancing the greenhouse effect much of the heat is absorbed by the oceans. In turn, this warmer water can hold less oxygen.

Stratification

The other worrying factor is the possible hindrance to replenishment of oxygen. This happens when the water is warmer than usual. Oxygen in the air and the surface usually gets dissolved in the water below by tides and winds. This helps restore the gas consumed by bacteria. When the temperature of the water is high, less dense water flowing into the ocean from rivers sits on top of salty dense water. This process is called stratification. A barrier is formed between the separated masses of water, hampering the replenishment process.

 

Picture Credit : Google