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Microplastic Hotspots In The Ocean | Earth Wise

June 4, 2020 By EarthWise Leave a Comment

Many of us are aware of the infamous ocean “garbage patches” of floating plastic. The Great Pacific Garbage Patch is roughly the size of Texas. But over 10 million tons of plastic waste enter the oceans each year and the floating patches only account for 1% of that total. The remaining 99% of the plastic ends up in the deep ocean, generally in the form of microplastics – tiny fragments of large plastic debris that have broken down as well as manufactured polyethylene beads used in various products.

According to a new study published in the journal Science, there are actually microplastic hotspots on the ocean floor, formed by deep-sea currents that act as conveyer belts moving the tiny plastic fragments around. One of these hotspots – in the Tyrrhenian Sea off the west coast of Italy – contained 1.9 million microplastic pieces in just one square meter of seafloor. This is the highest reported value for any place in the world.

Because of their small size, microplastics can be ingested by organisms across all levels of the marine food chain and eventually find their way into human diets.

The spatial distribution and ultimate fate of ocean microplastics are strongly controlled by near-bed thermohaline currents. These are deep-ocean currents driven by differences in water density, which is controlled by temperature and salinity. Thermohaline currents are known to supply oxygen and nutrients to the flora and fauna found at the ocean bottom. As a result, deep sea biodiversity hotspots are likely to be in same places where there are microplastic hotspots.

The discovery of these deep- sea hotspots is just another reason why we need behavior and policy interventions to limit the flow of plastics into natural environments.

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Seafloor microplastic hotspots controlled by deep-sea circulation

Photo, posted September 6, 2012, courtesy of Oregon State University 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.

The Rosewood Trade

April 3, 2019 By EarthWise Leave a Comment

Illegal trafficking in endangered flora and fauna is a topic of great interest and concern. We hear a lot about elephant ivory, rhino horn, and even pangolin scales. It turns out that the most trafficked form of flora or fauna in the world is actually rosewood. According to the United Nations Office on Drugs and Crime, rosewood is traded more than ivory, rhino horn, and pangolin scales put together as measured either by volume or economic value. According to Earthsight, a London-based nonprofit that investigates environmental crime, rosewood might account for 40% of overall illegal species trade.

Almost all rosewood is headed to China, where the beautiful wood is used in traditional hongmu furniture. A single bed made from particularly desirable Madagascar rosewood can cost a million dollars.

The illegal rosewood trade has decimated many species of the trees around the world. A tiny village in Madagascar has seen its population grow by 5,000 in recent years because of migrants coming to work as rosewood loggers. The rosewood trade has been banned in Madagascar for decades, but a well-established system of bribes has effectively eliminated that problem. Corruption at all levels allows Madagascar rosewood to find its way onto ships and off to China.

In 2017, the Convention on International Trade in Endangered Species of Wild Fauna and Flora listed all of the world’s rosewood species under its Appendix II, prohibiting all trade except in the rare cases where a local CITES authority issues sustainability permits.

As is the case for other trafficked endangered species, until the demand for the products disappears, people will find a way to make them available. And meanwhile, these beautiful trees are rapidly disappearing.

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The Rosewood Trade: An Illicit Trail from Forest to Furniture

Photo, posted November 17, 2007, courtesy of Larry Jacobsen via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Climate Change And Hawaii

December 18, 2017 By EarthWise Leave a Comment

The Hawaiian Islands are an archipelago of eight major islands, several atolls, numerous smaller islets, and seamounts in the North Pacific Ocean. The islands are a world-renowned vacation spot, known for their white-sand beaches, lush flora, and near perfect weather. But stormier days may be ahead.

Changing National Parks

January 12, 2017 By EarthWise

America’s National Parks are special places of incomparable beauty and fascination. When the National Park Service was first created 100 years ago, it was instructed to leave these places “unimpaired for the enjoyment of future generations.” We now live in a time when the changing climate is altering many aspects of the landscape including in many national parks. The parks are protected, but they are changing.