September 4, 2018

In July 2018, a herd of bison that had relocated to Canada’s Banff National Park in 2017 produced its first “made in Banff” calves (as Parks Canada is touting) in some 140 years. The bison babies were the first to be conceived and born in the area since the 1870′s. Two bison calves appeared on July 15, 2018, and a third followed on July 19. Six new calves arrived in August. North American bison are commonly called American buffalo.

“Little red” bison calves stay close to their mothers at Canada’s Banff National Park in July 2018. Credit: © Parks Canada

Banff National Park, Canada’s oldest, lies on the eastern side of the Rocky Mountains in southwestern Alberta. Known for its spectacular scenery, the park also boasts an impressive animal population that includes bighorn sheep, black bears and grizzlies, deer, elk, moose, mountain goats, and—since last year—a small herd of bison.

In February 2017, 16 bison, including 10 pregnant females, were moved to Banff’s Panther Valley from Elk Island National Park near Edmonton. Panther Valley is a remote wilderness area with wide, grassy pastures. The bison have thrived there, and the females produced 10 “made in Elk Island” babies last summer. (All the calves survived the year and are now nearly full grown.) The females then again became pregnant—in Banff, this time. The original herd of 16 expanded to 35, including nine “little red” bundles of joy. Bison calves are born with bright reddish fur; they later take on the chocolate brown color of their parents.

Bison graze in Elk Island National Park in Alberta, Canada. A bison herd from Elk Island was brought to Banff National Park in February 2017. Little red calves can be seen among the adults. Credit: © Parks Canada

Great herds of bison once roamed over North America between the Appalachian Mountains on the east and the Rockies on the west. Native Americans depended upon bison flesh for food and bison hides for clothing. In 1850, about 20 million bison still thundered over the western plains. Huge herds often forced railroad trains to stop while the animals crossed the tracks. In the late 1800′s, white hunters slaughtered millions of bison. This killing deprived the Native Americans of their main source of food and almost wiped out the bison.

By 1889, fewer than 1,000 bison could be found alive in the United States. Then efforts started to prevent the species from becoming extinct. Game laws and other protective measures allowed the surviving American bison to live and multiply. As a result, about 10,000 bison now live in national, state, and local preserves in the United States. About 3,000 bison roam on public lands in Canada. In addition, there are more than 300,000 bison on private ranches throughout the United States and Canada.

March 8, 2018

In 1918, 100 years ago, the Congress of the United States passed the Migratory Bird Treaty Act (MBTA) to help protect wild birds in North America from extinction. Bird populations, ravaged by habitat loss, overhunting, and pollution, had dropped sharply in the years leading up to the act. The MBTA helped preserve those populations and allowed them to recover and thrive. In late 2017, however, the administration of President Donald Trump weakened the protections provided by the MBTA, calling them an unnecessary burden to industry.

Bald eagles are one of more than 1,000 bird species protected by the Migratory Bird Treaty Act of 1918. Credit: © FloridaStock/Shutterstock

The widespread and largely unregulated growth of industry led to new pollution problems in the United States in the late 1800′s and early 1900′s. Wildlife of all sorts were threatened by pollution as well as the reduction of forests, wetlands, and other natural habitats. At that time, nongame birds in particular were threatened by the commercial trade in birds and bird feathers—especially in millinery (ladies’ hats). Species such as the sandhill crane, the snowy egret, and the wood duck were hunted to near extinction. The National Audubon Society and other conservation groups pushed Congress to pass the MBTA, which made it illegal to harm or kill migratory birds, either intentionally by hunting or “unintentionally” as a by-product of industry.

The MBTA saved millions of birds from the feather fashion trend (which did not last) and from many environmentally detrimental industrial practices. Congress levied heavy fines against industries that did not take common sense steps to prevent bird deaths. For example, a company could be fined for having oil, gas, or tar waste pits that birds mistake for typical ponds (resulting in poison deaths), or for having unmarked power transmission lines (resulting in collision or electrocution deaths). And in the case of environmental disasters, MBTA fines helped pay for the recovery of bird habitats. After the 2010 Deepwater Horizon oil spill in the Gulf of Mexico, BP, one of the world’s largest international oil companies, paid a $100 million fine under the MBTA (part of a much larger overall settlement). Most industries have readily complied with the MBTA over its long history.

On the eve of the MBTA’s 100th anniversary, however, the Trump administration changed how the act would be interpreted. The Department of the Interior said it would punish only the intentional killing of migratory birds. This move frees industries from responsibility for the “unintentional” killing of birds through environmentally unsound practices. The feather fashion industry may have gone away, but pollution has not; natural habitats continue to disappear, and environmental disasters continue to happen. Migratory birds have recovered largely because of the industrial application of the MBTA. Without it, birds are once again at the mercy of industry, which is much less likely to invest in precautionary measures to prevent bird deaths.

January 11, 2018

The axolotl, an unusual Mexican salamander, is one of the most studied animals in the world. It is also one of the most endangered animal species, and the axolotl may soon be extinct in the wild. Axolotls are popular as pets kept in home aquariums, and they are used in research laboratories worldwide. But in the wild, the amphibian’s numbers are depressingly small and getting smaller.

The axolotl is an unusual salamander with gills on the outside and a large tail fin. Unlike most salamanders, axolotls remain in the water throughout their lives. Credit: © Arco Images/Alamy Images

Axolotls are large compared with most salamanders. Axolotls can reach 12 inches (30 centimeters) long. The adult axolotl has a large tail fin and feathery external gills that extend out from behind the head. These characteristics are common to salamander larvae (young), which live in water. Most adult salamanders lose these features when they move to live on land. Adult axolotls, however, retain the gills and continue to live in the water. The axolotl is an example of pedomorphism <<PEE doh MAWR fihz uhm>>, the retention of juvenile characteristics by an adult. It’s as if they never grow up!

Scientists study the axolotl for its remarkable ability to regenerate body parts. The animals can grow back missing limbs, tails, organs, parts of the eye, and even portions of the brain. This ability makes the animal an important lab model in the study of tissue repair and development, as well as in the search for a cure for cancer. Axolotls are simple to study: they have very large cells and thrive in captivity. In the early 1900’s, axolotls were essential to understanding how organs develop and function in vertebrates (animals with backbones). Axolotls helped scientists unravel the causes of spina bifida in humans. In spina bifida, the spinal cord does not form properly and the vertebrae and skin cannot form around it.

In the wild, however, axolotls are having a much tougher time of it. The axolotl once thrived in lakes Chalco and Xochimilco in the area of Tenochtitlan, the ancient capital of the Aztec Empire and current site of Mexico City. The lakes do not exist anymore, and the few remaining wild axolotls live in the canals and other wetlands of the sprawling Mexican capital. These waters are badly polluted, however, by human waste, ammonia, heavy metals, and other toxic substances. Axolotls are defenseless against these lethal forms of pollution.

Invasive fish species such as carp, perch, and tilapia are also reducing wild axolotl numbers, competing with the unique amphibians for food and living space. To help preserve and expand the axolotl’s shrinking habitat, scientists are trying to revitalize traditional farming techniques that create floating islands in the canals and wetlands. These organic farming islands provide a healthy habitat for the axolotls, and they also help filter the polluted water. Whether or not this will be enough to save the axolotl from extinction in the wild remains to be seen.

December 15, 2017

On the Indonesian island of Sumatra, already home to the Sumatran orangutan, a new species of the great orange ape has recently been named: the Tapanuli orangutan (Pongo tapanuliensis). Orangutans are shy and reclusive, and they live in remote jungle areas. This, combined with their small numbers, can make the animals extremely hard to find. It is little wonder, then, that every once in a while people should learn of a new species. Since 2001, the Tapanuli is the third newly recognized species of orangutan, following its recently named Sumatran cousins (Pongo abelii) and the Bornean orangutan (Pongo pygmaeus). An international team of anthropologists and evolutionary biologists recently described the Tapanuli species in the journal Current Biology. Among all the great apes, the Tapanuli orangutan’s population is the smallest. The team estimated Tapanuli numbers at just 800.

A Tapanuli orangutan relaxes in the comfort of a tree on the island of Sumatra. Credit: Tim Laman (licensed under CC BY 4.0)

In the 1930’s, scientists reported an orangutan population in the rain forest of Batang Toru on Sumatra. However, it was not until 1997 that scientists rediscovered the population and later began studying the animals. Michael Krützen, a Swiss evolutionary geneticist from the University of Zurich, is one of the authors of the Current Biology report. Krützen believes the new orangutan species differs genetically, physically, and behaviorally from both the Sumatran and Bornean species. The three species also seem to have distinct evolutionary lineages. Tapanuli orangutans are believed to be direct descendants of the first orangutans that arrived in Sumatra from mainland Asia long ago.

Tapanuli orangutans are found only in the isolated high-elevation rain forest of Batang Toru. Their small population is distributed over about 386 square miles (1,000 square kilometers), an area roughly the size of Dallas, Texas. Calls made by Tapanuli males vary from calls made by Sumatran and Bornean males. Sumatran males produce calls that are long and low-pitched, while those on Borneo belt out shorter and higher-pitched calls. The calls of Tapanuli males fall somewhere in between.

Tapanuli orangutans have slightly different facial features (including a noticeable mustache) from other orangutans, as well as smaller skulls. Female Tapanuli orangutans have beards, unlike Bornean orangutans. Tapanuli fur is slightly different, too: frizzier and more cinnamon-colored. The analysis of Tapanuli bones, plus a genetic review of blood samples, convinced the anthropologists and biologists that they had found a unique orangutan species.

Jungle cats hunt Tapanuli orangutans, but otherwise the apes have few natural predators. Human activity poses the biggest threat. The spread of agriculture, particularly palm oil plantations, has greatly reduced the orangutan’s habitat. Plans for a gold mine and a hydroelectric plant in the area also pose threats to the animal’s Batang Toru forest. With only about 800 Tapanuli orangutans living in the wild, urgent study and conservation is needed to help protect the endangered orange apes from extinction.

December 6, 2017

Seventy years ago today, on Dec. 6, 1947, United States President Harry S. Truman officially opened southwestern Florida’s Everglades National Park. The park was established to conserve parts of the Everglades wetlands and the Big Cypress Swamp, as well as many coastal islands along the Gulf of Mexico. Covering 1,508,976 acres (610,661 hectares), the junglelike plant life of Everglades National Park includes saw grass, delicate orchids, lacy cypress trees, pines, palms, and thick tangles of mangrove trees. Crocodiles, alligators, manatees, and many other animal species live there.

Everglades National Park is in the Florida Everglades, one of the few subtropical regions of the United States. The southern part of the park includes many red mangrove trees, whose spreading roots catch and hold soil. Credit: National Park Service

In the late 1800’s and early 1900’s, land developers tried to drain parts of the Everglades wetlands, intending to turn the area into valuable real estate properties. Canals and levees diverted water from both the Everglades and nearby Lake Okeechobee, damaging the wetlands. Conservation efforts led to the creation of Royal Palm State Park in 1916, a protected area that steadily expanded and became the basis for Everglades National Park.

Everglades National Park includes large areas of wetlands that provide a home for wildlife. In this picture, roseate spoonbills wade near a young alligator. Credit: © Shutterstock

Further degradation of the Everglades—made worse by rising sea levels and heavy traffic on the park’s roads and waterways—sparked the Comprehensive Everglades Restoration Plan in 2000, a 35- to 50-year project meant to “restore, preserve, and protect the south Florida ecosystem while providing for other water-related needs of the region.”

November 10, 2017

Last month, in October, scientists in Germany warned that flying insect populations are rapidly declining. A study published in the scientific journal PLOS One revealed that about 75 percent of the flying insects in German nature preserves have disappeared in less than 30 years. The decline in natural areas of Germany could spell doom for flying insects—and many other forms of life—around the world. Quick action is needed to stem this decline, a serious matter referred to somewhat less seriously as the “windshield phenomenon” by some biologists (meaning there are fewer dead bugs to clean off automobile windshields these days).

A recent study showed alarming reductions in populations of flying insects, a group of animals that includes bees, butterflies, dragonflies, mosquitoes, and fireflies (pictured here). Credit: WORLD BOOK photo by Don Stebbing

Scientists have described and named more than 1 1/2 million species (kinds) of animals. Of these, about 1 million are insects. Scientists discover thousands of new insect species every year, and they believe there are many more yet to be found. Insects form the basis of many thousands of food chains. About 60 percent of birds rely on insects as part of their diet, and many types of bats, fish, spiders, and other animals also rely heavily on insects. In addition, about 80 percent of wild plants rely on insects for pollination. Without insects, many of these animals and plants would die. Without those plants and animals, many other forms of life would die.

For the long-term study, scientists at the Entomological Society Krefeld set up malaise traps (tentlike traps made of fine mesh material that catches a wide variety of insects) in 63 German nature preserves over the course of 27 years. Malaise traps are generally set out for long periods and checked every 7 to 14 days. The traps were placed in grasslands, sand dunes, swamps, wastelands, and other areas where insects should have been plentiful. By measuring the weight of the insect catch—known as the biomass—from each malaise trap, researchers detected the sharp drop in flying insect numbers. The decrease from 1990 was alarming: an 82 percent decline at midsummer (when the populations should be most active), and a 76 percent decline throughout the year.

Pesticides and habitat destruction are thought to be the main culprits behind the decline. Jason R. Cryan, deputy director and chief of research and collections at the North Carolina Museum of Natural Sciences in the United States, noted that “Although the study was conducted entirely in Germany, these contributory factors are common globally, and thus we can expect that insect population declines of similar magnitude are occurring in other regions of the world.”

Earlier this year, the Entomological Society of America (ESA) published two formal position statements on endangered insect species and arthropod biodiversity. The statements mention the critical role insects play in healthy ecosystems and note that insects are often early indicators of ecological shifts. The ESA has called for enhanced research and increased conservation efforts to reduce habitat destruction and the use of pesticides.

September 7, 2017

The pangolin, a reclusive, unusual insect-eating animal, is the world’s most trafficked (illegally traded) mammal. These armored but endangered animals live in tree hollows or dense thickets in remote forests and scrublands of Africa and Southeast Asia. Shy and largely nocturnal, the cat-sized animals are hard to find—which is a lucky thing. The pangolin is prized for its meat and the medicinal properties of its scaly armor. Were pangolins easier to find, they would have disappeared from the Earth long ago. As people continue to hunt them, however, and as deforestation shrinks their natural habitats, the pangolin’s days may still be numbered.

Pangolins are famous for their scaly armor and the habit of rolling up in a ball when threatened. Credit: © Shutterstock

Pangolins are slow-moving mammals that resemble anteaters and armadillos. However, they are not closely related to either, and, instead of the coarse hair of anteaters, pangolins have coats of overlapping brown scales. Like rhino horn, pangolin scales are largely composed of keratin, the same protein found in human hair and fingernails. Like anteaters, pangolins are toothless and have long, narrow snouts, long tails, and sticky, ropelike tongues that they thrust far out to catch ants, termites, and other tasty insects. Their large, strong foreclaws are used for ripping into tough ant and termite mounds and nests.

Pangolins are perhaps best known in popular culture for their unique defense mechanism. When threatened, they roll themselves into a tight, armored ball. With the exception of humans, few animals can harm pangolins. They are harmless animals, but they can also lash out with their scaly tails or emit a foul-odored scent like a skunk.

Pangolins and other illegally trapped wildlife suffer in cages in a market in Mong La, Myanmar, on the Chinese border. Credit: Dan Bennett (licensed under CC BY 2.0)

All eight pangolin species are threatened, and international laws and treaties protect their populations on paper. But the lucrative illegal trade powers on, and pangolins are being smuggled in record numbers. Poachers capture or kill hundreds of thousands of pangolins every year. And most of the animals—alive, maimed, or dead—are destined for China, where the meat is considered a delicacy and the scales are used in traditional medicine. Customs officials seize thousands of pangolins—often cruelly packed in tiny cages or boxes—and hundreds of pounds of pangolin scales each year. Despite its illegal nature, pangolin trafficking is often out in the open, even advertised. In June 2017, an Internet search revealed numerous traders on several websites selling pangolin scales, pangolin meat, and live pangolins. There is also an illegal trade in pangolin blood, and stuffed pangolins are unlawfully sold as souvenirs. Pangolins—like many wild animals—are also threatened by deforestation. They live in an ever-shrinking environment, leaving them with fewer places to hide from poachers.

And there is still more bad news for pangolins: they do not take well to captivity. Some animal populations can be saved or even restored in refuges, reserves, or zoos, but captured pangolins often simply die. They also do not reproduce in captivity, which prevents commercial breeding to supply China’s legal domestic medicinal trade. The only way to save these animals is to stop pangolin trafficking and preserve their natural homes.

Later this year, pangolins will be one of the topics at the Conference for the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) in Geneva, Switzerland. The goal is to list all pangolin species in Appendix I of CITES, which includes only species threatened with extinction. (Currently, two pangolin species are listed as critically endangered, and the others rank as vulnerable.) CITES is a treaty that aims to control trade in wild animals and plants, their parts, and products derived from them. Such a listing will draw more attention to the plight of pangolins, and it may encourage more people to help protect these humble creatures.

September 1, 2017

On remote Deserta Grande Island in the eastern Atlantic Ocean, a very rare and endangered spider is fighting for survival. A single valley on the island is home to the Deserta wolf spider (Hogna ingens), a stout and hairy burrowing spider found nowhere else on Earth. Deserta Grande is a small island among Portugal’s Madeira Islands. Deserta Grande once had a large population of these unique spiders, but habitat loss has reduced their numbers to an estimated 4,000 in the wild—a shockingly small population for an entire species of invertebrates (animals without backbones). The island, uninhabited by people, has fallen victim to an invasive grass that binds the soil so tightly that the spiders cannot burrow into it. This deprives the spiders of home and shelter, and their numbers have been greatly reduced. Help is on the way, however. At Bristol Zoo Gardens in the United Kingdom, Curator of Invertebrates Mark Bushell has begun raising his own Deserta wolf spiders, and he is part of a wider plan to replenish the spiders’ numbers on little Deserta Grande.

Mark Bushell shows off a tiny Deserta wolf spiderling at Bristol Zoo Gardens in the United Kingdom. Credit: © Bristol Zoo

In 2016, Bushell and Bristol Zoo veterinarian Richard Saunders traveled to Deserta Grande, where they collected 25 of the impressive black-and-white wolf spiders. The spiders are quite large, measuring up to 4 ¾ inches (12 centimeters) across, with a body size of 1 ½ inches (4 centimeters). Bushell and Saunders brought the spiders back to the zoo and have since successfully bred them. Tiny spiderlings, about 3/20 of an inch (4 millimeters) wide, emerged from tiny eggs, and the original 25 spiders have now multiplied to more than 1,000. The young spiders are incredibly delicate, however, and require committed and faithful care. In early 2018, Bushell will begin returning some of the spiders to their native island. Other young Deserta wolf spiders will go to other zoos to set up further safety net populations.

A conservation strategy to restore the native habitat on Deserta Grande is also in the works, a collaborative effort of the Bristol Zoo, the Instituto das Florestas e Conservação de Natureza of Madeira, and the International Union for Conservation of Nature in Switzerland. Working with local park rangers, the aim is to control or eradicate the invasive grass and restore the full breadth of the spider’s habitat. The Deserta wolf spider is listed as critically endangered, but it is not yet protected by any legislation.

July 21, 2017

In a study published in late June, scientists detailed the probable discovery of a new bird species: the blue-winged Amazon parrot. Its scientific name is Amazona gomezgarzai in honor of its discoverer, Miguel Gómez Garza, an ornithologist at the Autonomous University of Nuevo León in Mexico. Gómez Garza first saw the blue-winged Amazon parrot in 2014 in the Yucatán Peninsula while gathering information for his book, Parrots of Mexico. He and other researchers studied the unusual parrots for almost three years. The bird’s distinctive behavior, plumage, and DNA led Gómez Garza to declare the animal a new species.

Male (right) and female blue-winged Amazon parrots wait to scare other birds from nearby trees. Credit: Tony Silva (licensed under CC BY 4.0)

As its name suggests, the blue-winged Amazon parrot has blue-tinged wing feathers. It also has bright red plumage sprouting from its forehead and an all-green front. Other parrot species in the Yucatán have white plumage in front. Blue-winged Amazon parrots stand about 9.8 inches (25 centimeters) tall.

Like other parrots, the blue-winged Amazon parrot is noisy and sociable and lives chiefly in forested areas. The bird is very active with a seemingly limitless store of energy. The parrots live in flocks of fewer than 12 individuals, and mated pairs stay together with their offspring. The thing that truly sets the blue-winged Amazon parrot apart from other parrots, however, is its “singing voice.” Parrots are known for their ability to mimic sounds—Polly want a cracker? But this parrot goes a step further and imitates the call of a hawk. Now, hawks often feed on parrots, so why would the parrot want to imitate its predator? Scientists think the parrots do it to scare other birds from surrounding trees, leaving more seeds, fruit, and flowers for the parrots to eat. Scientists are still waiting, however, to see how the calls effect the nerves of other blue-winged Amazon parrots.

Through DNA research, the scientists believe that blue-winged Amazon parrots evolved from white-fronted parrots (Amazona albifrons) that were native to Yucatán about 120,000 years ago. Not all scientists are convinced, however, that white-fronts and blue-wings are actually different species. More study and genetic work is needed before blue-winged Amazon parrots can be conclusively labeled as a new species.

If the blue-winged Amazon parrot is in fact a distinct species, it is also an extremeley rare one. Scientists estimate their population at just 100 birds in the wild. The parrots face such human threats as deforestation and the illegal pet trade. Thankfully, plans are already in the works to save the parrots and their habitat.

June 29, 2017

The Bay of Bengal forms the northernmost part of the Indian Ocean. Bordered in an arc by the populous nations of Sri Lanka, India, Bangladesh, and Myanmar (also called Burma), the bay plays an important role in the lives of hundreds of millions of people. For thousands of years, people have subsisted on the bay’s rich marine life. With its waters dirtied and its sea populations dwindling, however, the bay’s fruitful abundance is lessening and may soon come to an end.

Traditional fishing boats crowd the harbor at Visakhapatnam, India, on the Bay of Bengal. Larger trawling vessels can be seen in the background. Credit: © Shutterstock

Covering an area of some 840,000 square miles (2.2 million square kilometers), the Bay of Bengal is one of the world’s largest marine ecosystems. The bay’s deep waters, coral reefs, estuaries, and mangroves provide a remarkable diversity of life. The rare Irrawaddy dolphin, which lives in fresh and brackish (slightly salty) waters, lurks in the muddy river mouths along the coasts. The bay’s salty and swampy mangrove forests provide a key habitat for Bengal tigers in India and Bangladesh, and for saltwater crocodiles, river terrapins, and other endangered species throughout the region. The dynamic mix of salt and freshwater habitats makes the coasts hotspots of fish biodiversity as well. At least 24 species of shrimp, 50 species of crab, and hundreds of different types of mollusks live in the bay’s shallower waters. These waters also host an abundance of squid and octopus species.

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The Bay of Bengal is the northern part of the Indian Ocean. The bay borders on India, Bangladesh, Myanmar, and Sri Lanka. Credit: WORLD BOOK map

The Bay of Bengal is best known, however, for its rich fishing. Seemingly endless populations of tuna, mackerel, sharks, reef fish, prawns, oysters, and other marine animals have long provided people with food and a steady income. For centuries, people fished the bay with pole and line, they trolled from light boats, or they practiced beach seining (hauling in nets anchored to the beach). These methods—which are still common today—produced ample results for both home and market, yet they did little harm to the bay’s overall fish stocks. Over the past 50 years or so, however, industrial fishing—which leans heavily on the use of trawlers—has largely supplanted the traditional sustainable fishing techniques, and the results have been disastrous.

Even such small stern trawlers as the one above catch large amounts of fish, including non-commercial marine species known as bycatch. Credit: © Colin Munro, Alamy Images

Trawlers use funnel-shaped nets called trawls to trap sea life. Trawls are very effective at corralling huge quantities of sea life, particularly valuable shrimp and prawns (often referred to as “pink gold” in the Bay of Bengal). A single trawler can catch many more fish in a day than a dozen or more traditional fishing craft. But trawling is a destructive fishing practice that can devastate marine ecosystems. The heavy trawls, usually weighed down and dragged along the sea floor, do not discriminate. They catch everything too big to slip through the net, including dolphins, rays, sea turtles, and many types of other non-commercial fish. These accidental catches are swept up in the nets, hauled on board the ship, and dismissed as bycatch. Some animals caught as bycatch are returned to the sea alive, but most die and are either discarded or sold to produce farm animal feed. Bycatch can constitute as much as 90 percent of a trawler’s haul—a devastatingly inefficient and wasteful percentage. Trawlers can leave a swath of lifeless sea in their wake, and they also hurt the sea floor itself. The heavy nets mow down sensitive corals and plant life.

In the Bay of Bengal, the switch from local to corporate and industrial fishing—to unsustainable and destructive trawling—has largely depleted the waters’ once-rich fish stocks. As fish hauls have decreased over the years, many traditional fishing families have had to find other ways of life. At the same time, trawling fleets—pushing ever further to find their elusive catch—have caused international disputes as they encroach upon foreign nations’ territorial waters.

Overfishing has done great harm to the Bay of Bengal, but ocean pollution may be the bay’s greatest enemy. Pollution has killed large amounts of marine life, poisoned or otherwise contaminated the bay’s waters, and even drained the life-giving abilities of the water itself. In some areas—including a massive “dead zone” in the middle of the bay—the once organically rich marine environment has become a tangled web of plastic garbage floating on oxygen-poor waters nearly incapable of supporting life.

Water pollution in the Bay of Bengal comes from many sources. Deep-water gas and oil drilling can cause great harm, as can ever-running boat engines and acid rain falling from the polluted air of the “brown cloud” drifting from the Asian mainland. The largest amounts of pollutants, however, come from the bay’s feeding rivers. Many major rivers empty into the Bay of Bengal, including the Meghna, the Ganges, and the Mahanadi. These mighty rivers carry fresh water into the salty bay, but they also bring pesticides and fertilizers from farming lands as well as massive amounts of trash and untreated sewage from urban areas.

Aside from the obvious harm from toxins, fertilizer runoff provides the bay’s plankton with an excess of nutrients. This causes the plankton population to rise sharply. The plankton then use up much of the water’s oxygen supply, leading to areas of hypoxic (low oxygen) waters. Few marine species can exist in hypoxic waters, so most animals either die or go elsewhere. In the center of the bay, a 37,000-square mile (60,000-square kilometer) area devoid of fish has appeared—a massive hypoxic zone often referred to as “dead.” Without action to reverse the bay’s decline, this dead zone may grow until, one day, it takes over the entire bay.

Anthropogenic (human caused) climate change, too, is threatening the Bay of Bengal. Climate change affects southern Asia’s seasonal monsoons, causing erratic, stronger, and unpredictable storms and flooding, increasing freshwater runoff and pollution and further deoxygenating the bay’s waters. Global warming leads to warmer ocean water temperatures and encourages the expansion of low-oxygen or even anaerobic (oxygen free) dead zones. Warmer ocean waters also melt polar ice at an increased rate, which causes sea levels to rise. As water inches up the Bay of Bengal’s coastline, it will displace millions of people. It will also take away land badly needed for agriculture, forcing humans to rely still further on fish from the bay—fish that soon may be nearly impossible to find.

As food security in Bay of Bengal countries becomes increasingly threatened and marine species become harder to find, slowing—or, if possible, reversing—the demise of the Bay of Bengal will become increasingly urgent. Bay communities and governments must choose more sustainable methods of fishing as well as more responsible methods of agriculture and commerce. At the same time, they must do their best to reduce pollution and waste. Many scientists see the plight of the Bay of Bengal as a warning signal to the rest of Earth. The bay is an example of a global trend in which unsustainable fishing methods, pollution, and climate change are slowly killing the world’s oceans. The Bay of Bengal is at a breaking point, but it is not too late to save it. Swift immediate and long-term action is needed, and the area’s people must make a genuine commitment to environmental responsibility.