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Sharks On The Decline | Earth Wise

September 4, 2020 By EarthWise Leave a Comment

During the past 70 years, global shark populations have been on the decline. Many species have become threatened or endangered. Conservation efforts have been underway in many places, but shark populations continue to be at risk because of over-fishing and habitat loss.

A comprehensive study by marine biologists at Texas A&M University deployed more than 15,000 baited remote underwater video stations on 371 coral reefs in 58 countries. The study included 59 different shark species in the Atlantic, Pacific and Indian Oceans. The researchers were surprised to find that no sharks at all were detected in almost 20% of the locations surveyed and were almost completely absent from coral reefs in several nations.

Scientists believe that demand for shark products, such as fins and meat, and bycatch (that is, sharks captured in nets by fisherman trapping other kinds of fish) are strong contributors to the widespread declines in shark numbers around the world.

The study shows that if corrective steps are not taken in regions where marine management is still ineffective, continued depletion of shark populations is highly likely.

Sharks have important roles in marine ecosystems. When their habitats deteriorate and their populations decrease, ecosystem stability and health is degraded because sharks help regulate prey populations.

Some countries, notably the Bahamas, are combating the problem by providing sanctuaries for sharks where fishing and harvesting is prohibited. Such places support some of the healthiest shark populations in the world. However, the decline of coral reefs is just another challenge facing shark populations around the world.

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Study Shows Alarming Decline In Shark Numbers Around The World

Photo, posted January 9, 2017, courtesy of Kris-Mikael Krister via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Wildlife Bridges

June 17, 2019 By EarthWise Leave a Comment

Highway accidents involving animals are a big problem for both people and animals. About 200 people die every year in the U.S. as a result of collisions with animals. In total, one to two million large animals are killed by motorists every year. And these crashes are expensive: deer-car collisions cost an average of more than $8,000 each; elk-vehicle collisions about $25,000; and moose-vehicle collisions over $44,000.

In the United States, there are 21 threatened and endangered species whose very survival is threatened by road mortalities. These include Key deer in Florida, bighorn sheep in California, and red-bellied turtles in Alabama.

One solution that has been quite effective around the world in reducing car-animal collisions is wildlife overpasses and underpasses. Crossings and fencing that guide animals over or under highways reduce collisions by 85-95%.

These traffic-spanning bridges and tunnels have been popular in Europe since the 1950s. The overpasses usually look much like regular overpasses for cars but are decked out with native flora. The underpasses, which assist shyer and smaller animals, are typically invisible to drivers.

Washington State has recently started building wildlife bridges and underpasses on Interstate 90. These passes will allow elk, black bears, mountain lions, pika, and even trout to traverse what was once a near-impenetrable barrier of road.

Some animals that are accustomed to human structures start using the crossings almost immediately. For others, there is learning curve. As in many things, the early adapters are important as they provide paths and model behavior that more reticent animals learn to follow.

Wildlife bridges are a very good thing for wildlife and for people.

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How wildlife bridges over highways make animals—and people—safer

Photo, posted July 22, 2017, courtesy of David Fulmer via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Fish And Ships

April 25, 2019 By EarthWise Leave a Comment

Solutions to overfishing of certain tuna and shark populations have been hindered by some significant unknowns: where the fishing is happening, and where the fish are. But researchers from Stanford University have recently shed some light on this mystery.

According to a paper recently published in the journal Science Advances, the researchers have developed a map of shark, tuna, and ship movements that could help ocean managers identify regions of the sea where vulnerable species may be at risk.

The researchers’ work builds on a 2018 study in which four years of satellite vessel movement data was used to develop a machine learning algorithm that mapped the footprint of 70,000 different fishing vessels around the world. In their paper, the researchers zeroed in on the activities of 900 vessels from 12 countries in the northeast Pacific Ocean to figure out to what degree fishing fleets, sharks, and tunas overlapped.

The researchers combined the vessel data with the ocean habitat preferences of sharks and tunas obtained from a decade-long tracking program called Tagging of Pacific Predators (or TOPP). According to the IUCN, most of the 876 individuals tagged in TOPP belong to species that are either threatened or near-threatened.

By synthesizing this data, researchers were able to map where sharks and tunas would have the highest overlap with commercial fishing vessels. Increasing the transparency of where fish meets fleets will allow ocean managers to determine where international protections may be needed.

The United Nations is currently developing the world’s first legally binding treaty to protect international waters. The Stanford University researchers hope their findings can help with this treaty’s formulation.

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Tunas, sharks and ships at sea

Photo, posted June 20, 2011, courtesy of Mike Baird via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Endangered Language Species

January 14, 2019 By EarthWise Leave a Comment

There are approximately 7,000 languages spoken in the world today but only about half of them are expected to survive this century. There are many factors contributing to the decline in languages. Perhaps the most significant is globalization, which pushes countries and individuals to shift to national or international languages for economic reasons. Other factors include the lack of support for regional languages in educational systems and mass media, persecution of minority linguistic groups by governments, and disruption of communities during war and emigration.

Predicting which languages will survive and which won’t is difficult. A potential tipping point for languages is the same one affecting the survival of species: climate change. Many small linguistic communities are located on islands and coastlines that are vulnerable to hurricanes and rising sea levels. Other communities live in places where increases in temperatures and erratic rainfall threaten traditional farming and fishing economies.

These climate-related changes will force communities to relocate,creating climate change refugees. Dispersing these people will lead to the splintering of linguistic communities and the need for the use of other languages. Such changes will place additional pressures on languages that are already struggling to survive.

There are endangered languages in many places around the world. Some are exotic such as the island of Sulawesi in Indonesia, which is home to dozens of distinct languages spoken by no more than a few thousand people. Others are much closer to home, such as in indigenous communities in Canada.

The rich tapestry of human language is just another of many things threatened by the changing climate.

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The Conversation: The impact of climate change on language loss

Photo, posted May 19, 2009, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Hunting Grizzly Bears

June 7, 2018 By EarthWise Leave a Comment

One year ago, the U.S. Department of the Interior announced that the grizzly bear population in the Yellowstone area would be delisted from the Endangered Species Act, and more recently, announced that those federal protections would not be restored.

Is The World’s Largest Sea Turtle No Longer Endangered?

January 29, 2018 By EarthWise 3 Comments

The rapid disappearance of many plants and animals around the world has many scientists saying we are experiencing a sixth mass extinction – the first since the dinosaurs were wiped out some 66 million years ago. Despite all sorts of conservation efforts, living things are struggling as a result of climate change, habitat loss, and countless other natural and manmade pressures. Conservation success stories have been few and far between.

Pine Barrens Threatened

September 29, 2017 By EarthWise Leave a Comment

Pine barrens occur throughout the northeastern U.S. from New Jersey to Maine. They are plant communities that occur on dry, acidic, infertile soils dominated by grasses, forbs, low shrubs, and small to medium-sized pines. The Pine Bush Preserve in Albany, New York is one of the larger inland pine barrens in the country.

Removing Heavy Metals From Water

September 7, 2017 By EarthWise

Clean and abundant water is the most essential need for all human societies and the supply of it is threatened by increasing populations and volatile climate patterns. The quality of water is threatened by a host of contaminants, most of our own making.

Yellowstone Grizzlies

July 27, 2017 By EarthWise

Grizzly bears once roamed much of North America and symbolized the continent’s untamed wilderness. But hunters and trappers nearly wiped them out across most of the Lower 48 states by the late 1800s.

Squeaking By

March 14, 2017 By EarthWise

Amphibians are one of the most threatened groups of animals on the planet. Since the late 1980s, scientists have measured dramatic population declines from locations all over the world. The plummeting amphibian populations are perceived to be one of the most critical threats to global biodiversity. According to the IUCN, about 1 of every 3 amphibian species is facing extinction. Some of the greatest threats facing amphibians include climate change, disease, and habitat destruction.

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Natural World Heritage Sites

May 5, 2016 By WAMC WEB

Natural world heritage sites exemplify the world’s greatest areas of natural beauty, ecology, geology, and biodiversity. They are recognized internationally for their value as places with significance that is “so exceptional as to transcend national boundaries and be of common importance for present and future generations of all humanity.” Many of these areas also are a vital source of food, fuel, and water for rural communities, and provide a revenue stream for national economies through tourism and recreation. The livelihoods of some 11 million people are directly dependent on these areas.

Ending The Protection Of Grizzly Bears

March 28, 2016 By WAMC WEB

Grizzly bears, also known as North American brown bears, once roamed much of North America and symbolized the continent’s untamed wilderness. But hunters and trappers nearly wiped them out across most of the Lower 48 states by the late 1800s.