My Science School

Scientists discovered a new species of marine creature in the deepest trench on Earth. In a normal scenario, this would have called for celebration. But this situation isn’t normal. Because the researchers also identified plastic in its body.

The amphipod is just two inches long and was caught at a depth of 20,000 feet in the Mariana Trench. The Mariana Trench in the Pacific Ocean is the deepest point on Earth’s surface, reaching more than 36,000 feet deep. Clearly, even this remote environment is not exempt from the impact of plastic pollution. The tiny creature had been found to have ingested tiny pieces of debris known as microplastics. The material they identified was polyethylene terephthalate (PET), common plastic widely used in food and drink packaging. To highlight the scale of marine plastic pollution crisis, researchers decided to name it Eurythenes plasticus. The creature is now one of the 240 known species to have been recorded ingesting plastic.

Plastic debris is now common throughout the world’s oceans. In fact, a 2015 study found that around eight million tones of the material enter the oceans every year. Once in water, this plastic can break down into smaller and smaller pieces, eventually becoming microplastics – frequently ingested by marine animals. Thousands of animals, from sea birds to whales, die every year from consuming or getting caught in plastic.

 Pollution in Alarming scale

• According to a 2017 study, humans have produced 18.2 trillion pounds of plastic since the 1950s. Only 9% of it has been recycled and another 12% has been burnt. A majority of the plastic ends up in landfills and the oceans. The debris is often carried by wind and rain into our drainage networks and eventually into the sea.


• A report released by Ellen MacArthur Foundation at the World Economic Forum in 2016 estimated that at least eight million tones of plastics leak into the ocean – this is equal to dumping the contents of one garbage truck into the ocean every minute. The report further says the ocean is expected to contain one tonne of plastic for every three tonnes of fish by 2025, and by 2025, there will be more plastic than fish by weight in the ocean.

What are microplastics?

Most plastic in the ocean break down into very small particles called microplastics and make their way into the system of marine animals. Plastic particles that are less than five mm long are called microplastics. Microplastics come from a variety of sources, and are of two types – one that are manufactured (microbeads) and the other that are derived from the breakdown of larger plastic debris. Besides water, microplastics have been found in soil and air.

How plastic affects marine ecosystem

Sea turtles and other marine creatures mistake plastics for food (such as jellyfish) and ingest them. This causes blockage in their digestive system, leading to their death. Studies have found that plastic pollution can also affect sea turtles’ reproductive system.

In sea birds, plastic ingestion reduces the storage volume of the stomach, causing starvation and death.

Besides ingestion, marine mammals get tangled up in plastic, leading to their death.

Plastic may also get transferred along the food chain – from fish to bigger fish or marine mammals and finally to human seafood consumers.

Invisible threat

Marine species also face the invisible threat of plastic-derived chemicals. It was long held that plastic broke down only at very high temperatures and over hundreds of years. A study in 2009 showed that some plastics decompose rapidly in the ocean, even within a year of the trash hitting the water. The degrading plastics also leach potentially toxic chemicals such as bisphenol A into the seas, possibly threatening ocean animals, and human, who ultimately consume some of these creatures.

• Direct toxicity of plastics comes from lead, cadmium and mercury added to them while manufacturing plastic products. These toxin s have been found in many fish in the ocean.


• When expanded polystyrene, used especially for making food containers, breaks down, the tiny polystyrene components start to sink, as they are heavier than water. Exposure to polystyrene can cause irritation of the skin, eyes and the upper respiratory tract in humans. Acute exposure may also result in gastrointestinal effects.


• Bisphenol A (BPA) has been shown to interfere with the reproductive systems of animals. In humans, even low doses of bisphenol A can impair immune function and cause cancer, obesity, diabetes and hyperactivity, among other problems.


• Diethylhexyl phthalate (DEHP) contained in some plastics, is also carcinogenic (cancer-causing).

 

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Locusts are large insects. They are special grasshoppers. They have big hind legs used for jumping. All grasshoppers (except the long-horned, ones) belong to the Acridoidea family, and the most important Locusts are all in the family Acrididae. Locusts can change their habits and, behaviour when they occur in large numbers their numbers rise they stay together in dense groups called, "swarms." These are groups of adults. Locust groups are called "bands" when; they consist of the wingless young ones, commonly called 'hoppers'. Locust swarms migrate over great distances, and, this behaviour differentiates them from other grasshoppers. When, locusts are in small numbers they live their individual lives like ordinary grasshoppers. These could be small groups that stay in one place. Some species of locusts are regarded as intermediate between grasshoppers that live alone and typical locusts that do not.

Locusts have the capacity to multiply rapidly and produce groups or swarms in special circumstances. Their population explosion can be started by unusual weather conditions or changes in land use. This is what happened this year. According to the UN, the heavy infestation this year can be traced back to cyclone season of 2018-19 that brought heavy rains to the Arabian Peninsula. This allowed at least three generations of "unprecedented breeding" and no one noticed it. Swarms have since spread out into South Asia and East Africa. David Phiri, a FAO regional, coordinator said that whew weather conditions are good for locust breeding, there is a high probability that the insects will continue to spawn rapidly. This year it may go on till April. Locusts have probably been man's enemies ever since humans began to grow crops. The Old Testament (Bible) and the Koran mention the desert Locust. You can see carved, images of Locusts in Sixth Dynasty (2420-2270 BC) tombs at Saqqara in Egypt. Now, in countries like Somalia, Locusts can determine whether people will have sufficient food or starve. The damage they cause can be mild to very severe. This depends on whether the swarms are moving about quickly or whether they stay for several days in one area.

FAO describes the desert Locust, schistocerca gregaria, as the world's "most dangerous migratory pest, with a, voracious appetite unmatched in the insect world." Swarms can vary from, less than 1 sq km (0.38 square miles) to several, hundred. Each square kilometre can contain at Least 40 million insects, according to FAO. FAO's Western Africa joint Locust control force was established, in 2016 and includes Mauritania, Algeria, Burkina Faso, Morocco, Niger, Senegal, Chad, Libya, and Mali.

 

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The word "locust' has been in the environment sections of all newspapers for some time. On some days, news about them appeared on the front page. Here are samples.

[1] 'The UN's Food and Agriculture Organisation (FAO) said earlier this week that Somalia and Ethiopia were facing a Locust infestation that is destroying crops and threatening food security in the region. On Saturday, Somali farmers urged their government and the international community to help protect crops from the invasion."

[2] 'The FAO has reported farmers are facing "devastating threat" to their crops." "A single locust plague can lead to a loss of 170,000 tonnes of grain, enough to feed one million people for a year," the organisation said. The insects have already destroyed at least 175,000 acres of farmland in Somalia and Ethiopia, according to the FAO.

[3] A swarm of what appeared to be locusts forced a passenger plane off its course in Ethiopia. Pilots were preparing to land the Ethiopian Airlines flight from Djibouti to Dire Dawa when clouds of insects slammed into the plane's engines, wind-shield and nose. They tried in vain to clean the windscreen with the plane's wipers. Thirty minutes later the plane landed safely in the capital Addis Ababa."

[4] "Somalis fight invading Locusts by eating them. Somalis are battling the worst invasion of Locusts in 25 years. They have resorted, to eating the insects to stop them from destroying crops. Local media reports have shown, residents central Somalia frying Locusts and serving them with rice, with one man staging the desert insects are tastier than fish.. Another man told Universal Somali TV he believes eating the insects could, help reduce his back pain and blood pressure, while some residents have apparently urged local restaurants to introduce locust dishes.”

[5] "Mauritania is planning to use drones to monitor the Locust swarms in the locust swarms in their country." 'The drones will track and monitor desert Locusts and instigate early-warning operations before the swarms arrive so that appropriate action can be taken," said a report. The Latest round of tests, announced, in September 2019, will represent a "critical stage" in the fight against the locust plague, Secretary-General of the Mauritanian Rural, Development Ministry Ahmedou , Ould Bouh said.

This year’s tests are expected to confirm whether improvements made to drones wilt demonstrate their usability in the harsh desert conditions, and pave the way for their wider use in the region.

[6] "Pakistan declared an emergency earlier in February, 2020, saying locust numbers were the worst in, more than two decades. The Chinese government announced, recently it was sending a team of experts to Pakistan to develop "targeted programmes" against the Locusts." They would send ducks to control the numbers of Locusts. "An agricultural expert behind the scheme says a single duck can eat more than 200 locusts a day and can be more effective than pesticides. Lu Lizki, a senior researcher with the Zhejiang Academy of Agricultural Sciences said that the ducks are "biological weapons". He said that while chickens could eat about 70 Locusts in one day a duck could devour more than three times that number. After a trial, the ducks would be sent to Pakistan's worst-affected areas of Sindh, Balochistan and Punjab provinces. "China could, deploy 100,000 ducks to neighbouring Pakistan to help tackle swarms of crop-eating locusts.”

However, a professor from the China Agriculture University, who is part of the delegation to Pakistan, questioned, whether the ducks would be suited to the mainly arid conditions where the Locusts are a problem. "Ducks rely on water, but in Pakistan's desert areas, the temperature is very high," Zhang Long told reporters in Pakistan."

 

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India was once home to tens of thousands of Asiatic cheetahs. But overhunting and habitat destruction pushed the animal to the brink. In 1947, Maharaja Ramanuj Pratap Singh Deo of Koriya (now in Chhattisgarh) reportedly killed the last known Asiatic cheetah in India. In 1952, the cheetah was officially declared extinct in India.

But with the Supreme Court having cleared a proposal to introduce African cheetahs on an experimental basis, India may soon welcome a bunch of the spotted big cats from Namibia. But before that the authorities will have to identify a suitable habitat for the programme, assessing factors such as prey availability and the risks of human-cheetah conflict.

Among the sites that have been suggested for the relocation are the Kuno-Palpur Wildlife Sanctuary in Madhya Pradesh, the Velavadar National Park in Gujarat and the Tal Chapar Sanctuary in Rajasthan.

This is not the first time that the Indian government has tried to bring back the Cheetah. In the 1970s, officials tried to secure Asiatic cheetahs from Iran. But negotiations hit a roadblock after the Islamic Revolution of 1979 in Iran. (Today, Iran is home to the world’s last stand of Asiatic cheetahs-fewer than 50 individuals.) In 2001, scientists came up with a proposal to clone Asiatic cheetahs, but the plan fell through for various reasons.

The focus then shifted to importing African cheetahs, a distinct subspecies from the Asiatic cheetah, found in decent numbers throughout Africa. But this approach has received mixed reaction from conservationists and scientists. While some welcome it, others question the feasibility of the project.

ABOUT CHEETAHS

• Cheetahs inhabit wide, open grasslands and arid habitats such as scrub forests.


• They have a pale yellow coat with black dots on the upper part, while the underbelly is white. A cheetah can be identified by its spots and the black tear-like streaks on its face.


• These cats have long tails, which enable them to balance while running fast.


• The cheetah is the world’s fastest land mammals. It can reach a speed of 112km/h in just three seconds.


• Cheetahs are carnivores and live off animals such as antelopes, rabbits, warthogs, springboks and birds.


• They are usually found in groups, consisting of either a mother and her cubs, siblings or a group of males that live and hunt together.


• The vast majority of cheetahs now live in Africa, while the Asiatic cheetah subspecies comprises a population numbering less than 50 in Iran and is considered critically endangered, according to the International Union for Conservation of Nature’s (IUCN) Red List of Threatened Species.


• The population of cheetah is declining due to human-wildlife conflict, decline of prey, loss of habitat and illegal wildlife trade.

HOW CHEETAHS BECAME EXTINCT IN INDIA

Cheetahs are fast but docile by nature. These two traits sealed the fate of the animals in India. The spotted big cats had been hunted and captured indiscriminately since the 1500s. Kings across the country captured thousands of them from the wild to be tamed as trained to race and hunt animals such as antelope. The Mughal emperor Akbar is said to have kept 1,000 in his royal menagerie. But the inability of cheetahs to breed in captivity meant that wild cheetahs had to be constantly captured from their natural habitat. This led to a steady drop in their population. When the British colonists arrived in India, cheetahs were already scarce. For their part, the British degraded grasslands across India, leading to the cheetah’s eventual extinction in 1952.

THE DEBATE OVER THE CHEETAH INTRODUCTION PROGRAMME

Against

• Conservationists believe that introducing African subspecies to India could affect their genetic make-up. Substituting one subspecies for other risks erasing valuable genetic adaptations, they say. African cheetahs may not be able to adapt to the grasslands of India.


• India does not have the kind of grassland habitats it once had. They have been replaced by agricultural land or encroached upon by people over the past few decades.


• The proposed habitats in India are not large enough to accommodate cheetahs and the areas do not have enough prey to sustain the big cats.


• Some conservationists say that the plan to introduce cheetahs is a case of misplaced priorities. India should rather focus on conserving endangered species already living in the country instead of reviving an extinct species.

For

• Proponents of the cheetah introduction programme are positive that African cheetahs can adapt to Indian condition.


• They believe that the cheetah conservation programme could return the grasslands back to their past glory. While conserving the cheetahs, efforts will be made to save the grasslands ecosystem and biodiversity will be restored.


• If cheetahs are introduced successively, India will be home to all of the big cat species in the Old World: tigers, lions, leopards, snow leopards and cheetahs.

 

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Odisha Forest Department officials, wildlife experts and researchers carried out the 2020 dolphin census in the State’s aquatic ecosystems, including the Chilika lake, the Rushikulya river and off the Gahirmatha coast. Though Chilika recorded 146 Irrawaddy dolphins, a spike from 130 in 2019, the overall count of dolphins in Odisha’s waters was at 233 dolphins, down from 259 in 2019 and 469 in 2018. The consistent drop was also observed at Gahirmatha, where the population has almost halved from last year. Forest officials spotted only 62 dolphins during the census. In 2019, it was 126 and in 2018, 307! The dolphin species sighted during the State-wide census include the Irrawaddy, the bottle nose and the humpback.

India is also home to the iconic Ganges (or Gangetic) river dolphin, which is also the National aquatic animal. But this honour has not given the species an advantage over fellow dolphin species , when it comes to survival. Ganges river dolphins once lived in the Ganges-Brahmaputra-Meghna and Karnaphuli-Sangu river systems of Nepal, India and Bangladesh. But the species is disappearing from most of its distribution ranges. These dolphins are one of the three surviving freshwater dolphin species in the world. The other two are found in the Indus in Pakistan and the Amazon in South America. A fourth species, the Yangtze river dolphin in China, has gone extinct.

Gangetic river dolphins are categorised under Schedule I of the Indian Wildlife (Protection) Act and have been placed on the red list of the International Union for Conservation of Nature (IUCN), which signifies that the species is on the verge of extinction.

So, why is the dolphin population declining?

ABOUT DOLPHINS

• Dolphins are aquatic mammals within the infraorder Cetacea, which also includes whales and porpoise.


• Dolphins are recognised by their set of small teeth and curved or beaked mouths, putting an eternal smile on their face. They have streamlined bodies and two limbs that are modified into flippers. They have a layer of fat, or blubber, under the skin to keep them warm in cold water.


• Most dolphins live in the ocean or brackish waters along coastlines, but there are a few such as the Ganges river dolphin that live in freshwater streams and rivers.


• Dolphins feed largely on fish and squid, but a few, such as the killer whale, feed on large mammals such as seals.


• Dolphins are highly social creatures, living in pods. They communicate with squeaks, whistles and clicks.


• Bottlenose dolphins have been found to have signature whistles, with each individual having a unique sound.


• Dolphins help each other in times of distress. They have also been seen helping other species. They have been spotted helping fishermen by leading them to a school of fish to catch. They have been seen protecting swimmers from sharks by swimming around them or preventing sharks from getting closer to the swimmers.


• Generally, dolphins sleep with only one brain hemisphere shut at a time, thus maintaining enough consciousness to breathe and to watch for possible predators and other threats using the other.

ECHOLOCATION

Just like bats, dolphins (whales and porpoises) use echolocation to navigate through the dark, murky waters. Echolocation allows dolphins to “see” by interpreting the echoes of sound waves that bounce off objects near them in the water.

To echolocate, dolphins produce high-frequency clicks. These clicks create sound waves that travel quickly through the water around them. Dolphins and whales use this method to sense an object’s distance, direction, speed, density and size. Using echolocation, dolphins can also differentiate between species.

They also use echolocation to communicate.

INTELLIGENCE

Since there is no concrete definition of intelligence, scientists refuse to take a firm stand on the dolphins’ intelligence. They engage in creative play, show empathy towards member of their species and other species, use tools, pass knowledge on to next generation, mourn the death of a fellow dolphin, and collaborate with each other within a pod to complete a task. Their form of communication is diverse and evolving. Through experiments, scientists have shown that dolphins have an excellent learning ability. They respond to images on television and imitate the actions of human beings.

GANGES RIVER DOLPHINS:

• Gangetic river dolphins live in shallow, often narrow, stretches of the rivers.


• They have long, pointed noses, prominent teeth and a brownish, stocky body.


• Gangetic river dolphins are effectively blind. They depend on echolocation to navigate, play, find food, mate and flee from danger. They produce ultrasonic or high-frequency clicks in the 20- to 160-kilohertz range.


• Ganges river dolphins are the top predators in their river ecosystems. They are important in controlling and maintaining healthy fish and crustacean populations, their primary sources of food. Unfortunately, these river dolphins are facing the adverse effects of human impact.

THREATS TO DOLPHINS

• In the marine ecosystem, dolphins have few enemies. For smaller species of dolphins, the larger sharks are potential threats.


• Dolphins also suffer from a wide variety of diseases and parasites.


• Their main threat comes from being caught accidentally in commercial fishing nets. Entanglement prevents dolphins from rising to the surface to breathe, which eventually kills them.


• As dolphins use echolocation for most of their activities, noise pollution from ships disorient them. It also affects their brain, causing internal bleeding, studies suggest.


• For freshwater dolphins, threats come in the form of pollution – caused by pesticide run off and discharge of industrial and municipal waste. Injuries or deaths due to collisions with boats, entanglement in fishing gear, degradation of habitat, poaching and global warming are some of other threats.

 

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Species loss

Wildlife trafficking threatens the survival of some of the Earth’s most iconic species. For instance, between 2014 and 2017, more than 1,00,000 African elephants were killed for ivory. In 2011, the International Union for the Conservation of Nature (IUCN) declared the Western black rhinoceros extinct and cited poaching as the primary reason. According to the World Wide Fund for Nature (WWF), wildlife crime is second only to habitat destruction in overall threats against species survival.

Biodiversity loss

Wildlife trade affects food chain and threatens the local ecosystem. For instance, the loss of a predator species can results in the overpopulation of the prey species, leading to disruption in the ecological balance.

Poor conditions of animals kept for trade

Animals captured for pet trade are transported in poor conditions. They are stuffed into boxes, suitcases, or sacks. Even if they survive the transport, they often suffer in their new, unnatural surroundings. Many animals are kept in markets for months, waiting to be sold, with even their basic needs unattended to.

Impact on humans

As we saw earlier, poached animals can spread diseases, such as Ebola and SARS. Poaching also puts local people and officials at risk. In Africa, nearly 600 rangers in charge of protecting wildlife were gunned down by poachers between 2009 and 2016 while in the line of duty.

Different countries employ different methods to curb poaching. Though some efforts have borne fruit, illegal wildlife trade continues unabated.

 

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• Wildlife trade is a big business, run by international networks. Animals and birds are trafficked across the globe for meat, skin, bone, fur and other body parts. In addition, many species are sold as pets. Experts at TRAFFIC, the wildlife trade monitoring network, estimate that the illegal wildlife commerce runs into billions of dollars.


• Not all wildlife trade is illegal. The sale or exchange of wild animals and plant resources are done legally for various purposes. Regulated by the United Nations’ Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), it is done in a sustainable manner. Wild plants and animals from tens of thousands of species are caught from the wild and then sold legitimately as food, pets, ornamental plants, leather, ornaments and medicine.


• A trade becomes illegal when wildlife listed as protected under domestic or international law is hunted. Fishing and hunting without a licence and capturing wildlife from protected areas and during certain seasons also amount to wildlife crimes.

Did you know?

• Elephants are poached for their tusk, skin and meat. Ivory is used to make billiards balls, piano keys, art objects and jewellery.


• Rhinoceros are killed for their horn, which is predominately used in traditional Chinese medicine.


• While freshwater turtles and pangolins are hunted for their meat, their body parts namely, carapace and scales, respectively, are used in Chinese medicine.


• Tigers and leopards are killed for their skin.


• Snakes, ape and monitor lizards are consumed as meat.


• Song birds, finches, macaws, weavers, cockatoos, geckos, aquarium fish, turtles are captured alive so that they can be kept or sold as exotic pets.

 

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In the wake of the corona virus epidemic, China has temporarily banned the sale of wildlife in markets, restaurants and over e-commerce as part of efforts to contain the outbreak. While welcoming the move, conservationists are calling for a permanent ban as it will contribute to the recovery of wildlife populations worldwide, besides saving human lives.

The corona virus, which results in a zoonotic disease, is thought to have originated in a “seafood” market in Wuhan that sold much more than fish. Chinese authorities found everything from hedgehogs and wild boars to crocodiles for sale there, providing ideal conditions for viruses to jump to new hosts and ultimately, to people. (Zoonotic diseases spread from animals to humans.) Consumption of several vulnerable species – for example, pangolins, rhinos, elephants – is common in China. There is another theory that believes that pangolin may have passed the virus from bats to humans. Pangolin is imported in huge numbers to Chinese markets for food and medicine.

A host of other animals too are important to China for meat, medicine etc. through illegal wildlife trade. China may be the world’s largest market for wildlife products, but wildlife trade is rampant throughout the world. Wildlife trafficking puts many animals and birds at risk of extinction. A study published last year estimated that one in every four bird or mammal species on earth is caught in the wildlife trade.

 

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