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The Dead Zone In The Gulf Of Mexico | Earth Wise

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The Gulf of Mexico has an area of low to no oxygen in the water that can kill fish and other marine life.  It is an annual event that is primarily caused by excess nutrient pollution from human activities in urban and agricultural areas throughout the Mississippi River watershed.   When these excess nutrients reach the Gulf, they stimulate the overgrowth of algae, which eventually die and decompose, depleting the oxygen in the water as the algae sink to the bottom.

These low oxygen levels near the bottom of the Gulf cannot support most marine life.  Some species – among them many fish, shrimp, and crabs – swim out of the area, but animals that can’t swim or move away are stressed or killed by the low oxygen.  The dead zone in the Gulf occurs every summer.

A recent forecast for this summer’s dead zone predicts that the area of low or no oxygen will be approximate 6,700 square miles, which is roughly the size of Connecticut and Delaware combined.  This is about 1,100 square miles smaller than last year’s dead zone and much less than the record of 8,776 square miles set in 2017.  But it is still larger than the long-term average size of 5,387 square miles.

Making comparisons to the long-term average ignores the fact that the long-term average itself is unacceptable.  The dead zone not only hurts marine life, but it also harms commercial and recreational fisheries and the communities they support.  The actions that have been taken so far to reduce pollution in the Mississippi watershed are clearly not sufficient to drastically reduce the dead zone in the Gulf.

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Large ‘dead zone’ expected for Gulf of Mexico

Photo, posted October 17, 2017, courtesy of NOAA’s National Ocean Service via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

American Robins And Climate Change | Earth Wise

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American robins are migratory songbirds that can be found throughout much of North America.  Named after European robins because of their reddish-orange breast, American robins are often found hopping across lawns and nesting on porches.  Their rich caroling is among the first pre-dawn bird songs heard in spring and summer.  

While some overwinter in northern parts of the United States and southern Canada, most American robins migrate south to overwinter in places like Florida and the Gulf Coast, as well as central Mexico and the Pacific Coast.  They typically head south by the end of August and return north sometime between February and March to their breeding grounds in Canada and Alaska.  They spend their short time there trying to find a mate, build a nest, raise a family, and consume enough food to sustain themselves on their long return journey south.

But climate change is making these seasonal rhythms less predictable.  According to a new study recently published in the journal Environmental Research Letters, American robin migration is kicking off earlier by about five days each decade.  The birds now migrate 12 days earlier than they did in 1994.  

For 25 years, researchers at Canada’s Slave Lake have been recording the timing of American robin spring migration.  They attached GPS devices to 55 robins, tracking their movements from April through June. The researchers linked the birds’ movement with weather data, including air temperature, snow depth, wind speed, and precipitation.  The results showed that robins start migrating north earlier when winters are warm and dry. 

Understanding the influence over the timing of migratory events is important because the timing of migration can influence reproductive success.

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A Migration Mystery

American robins now migrate 12 days earlier than in 1994

Photo, posted January 1, 2020, courtesy of Becky Matsubara via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

More Trouble For Monarchs | Earth Wise

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Monarch butterflies have been in trouble for quite a while and now it seems like their prospects are worse than ever.  Multiple surveys of butterfly populations are reporting plummeting numbers.

Western monarch butterflies spend their winters on the central California coast.  Months later, they breed in California’s Central Valley and as far north and east as Idaho.  But in recent years, it has become harder and harder to find them in their breeding sites.

The Western monarch population was in the millions in the 1980s.  In 2017, an annual survey found 200,000 butterflies.  In 2018 and 2019, only about 30,000 butterflies were tallied.  The loss of Western butterflies in general has come about from a variety of factors, including development, climate change, farming practices and the widespread use of pesticides by farmers and on home and business lawns.

Scientists use the area of land that migrating Monarchs occupy in Mexico to gauge populations.  This year, they covered about 7 acres, down from 15 acres in 2019.

Meanwhile, there are also far fewer Eastern monarch butterflies on the opposite side of the country.  According to a new population survey, the Eastern monarch has passed the extinction threshold.  Its population in 2020 dropped 53% from its already low 2019 numbers.  Scientists were expecting lower numbers this year, but they were staggered by their findings.

Butterfly populations are quite variable, so it is possible that the drastic declines this year are not necessarily irreversible, but the news is not good.   Researchers and environmental advocates continue to point out that mitigating the climate crisis, reducing pesticide use and planting pollinator gardens could help the butterflies to recover.

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Monarch Butterfly Populations Are Plummeting

Photo, posted September 7, 2017, courtesy of C. Watts via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Mexico’s Wonder Plant

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In 1979, an American naturalist named Thomas Hallberg visiting a small town in Oaxaca, Mexico was amazed to find a type of local maize – or corn – that grew nearly 20 feet high in poor-quality soil even though the local farmers did not use any fertilizer.

The unique corn plant had aerial roots that grew a mucous-like gel just before harvest season.  It seemed totally implausible, but the plant seemed to be fixing its own nitrogen:  extracting it from the air and somehow making it useful to the plant.

In 1992, Hallberg returned with a group of Mexican scientists and collected samples to study in his lab.  His research showed that the maize indeed received nitrogen from the air through its aerial roots.  It took over 20 years to figure out what was going on in the plants.  It turns out that bacteria that thrive in the low-oxygen environment of the maize’s mucus pulls nitrogen from the air and feeds it to the plant.

Scientists will probably spend years figuring out if a commercial application of this indigenous maize is viable.  It isn’t guaranteed that the self-fertilizing trait of the plant can be bred into a commercial crop.  But if it can, the payoff would be huge.  Farmers spend more than $3 billion a year on corn fertilizer in the US alone.

A vexing problem is who should reap the financial benefits of the maize.  The isolated village where the plant is grown has already signed an agreement to share in any such benefits.   But there are other Oaxacan villages that also grow the plant. 

Mexico’s wonder plant is likely to be caught up in the growing issue of biopiracy, which is the exploitation of indigenous knowledge and biological resources without permission.

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Indigenous Maize: Who Owns the Rights to Mexico’s ‘Wonder’ Plant?

Photo credit: ALLEN VAN DEYNZE/UC DAVIS

Earth Wise is a production of WAMC Northeast Public Radio.

Keeping Lights On For Turtles

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Gillnets are one of the most common types of fishing gear and are used extensively in most places where people fish for food.  They operate by suspending a wall of netting in the water column.

Unfortunately, they are not selective in the species they catch.  Sea turtles are one of the most common bycatch species that become entangled in these nets.  When turtles are caught in gillnets, they can drown and die.  Marine mammals, seabirds, and sharks are also frequently caught in gillnets.

Recently, researchers have been experimenting with illuminating the nets with LED lights to see if increasing net visibility reduces sea turtle bycatch.

Studies in Mexico show green sea turtle bycatch is reduced between 40-60% with no changes in target catch.  Studies in Peru show green sea turtle bycatch is reduced between 65-80% with no changes in target catch.  Studies in Indonesia show green olive ridley, and hawksbill sea turtle bycatch is reduced by 60% with increases in target catch and catch value.

Recent research shows that net illumination also reduces bycatch of other protected species such as seabirds, sharks and rays, as well as dolphins and porpoises.

The use of illuminated gillnets could prove beneficial to both sea turtles and fisherman by reducing the bycatch that can damage fishing gear. 

Studies are now underway off the coast of North Carolina, where state gillnet fisheries are carefully managed to reduce turtle bycatch.  Initial studies show that net illumination does not change target catch rates and may even decrease the bycatch of unwanted fish species.  When it comes to protecting sea turtles, it looks like a good idea to keep the lights on.

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Illuminated Nets Could Provide A Brighter Future For Sea Turtles

Photo, posted June 2, 2016, courtesy of NOAA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Powering Cars With Cactus Juice

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Back in 2016, a company called Nopalimex, located in Micoacan, central Mexico, built the world’s first cactus-powered energy plant.  The facility utilizes a biodigester to make biogas from nopal, also known as prickly pear cactus.  The nopal plant has been called the ‘Green Gold of Mexico’ and is a staple in Mexican diets, medicine and cosmetics.

Nopalimex is now using the cactus to make biofuel for vehicles.

The fruit of the cactus is pureed, mixed with manure, and then left to decompose, producing methane.  The methane produced – about eight tons a day – fuels the biodigester which powers the company’s corn chip and cactus chip production and is being tested in a fleet of government vehicles.

The biogas will cost just 65 cents per liter, which is about a third cheaper than the cost of regular gasoline.  Using prickly pear as a feedstock for biofuel is attractive because it can be grown in places where traditional energy crops cannot.  One can imagine vast fields of cacti in remote, arid areas of the country where normal crops cannot grow.  It would not suck up the resources or space needed to feed people, which is an ongoing criticism of current bioenergy crops.

As long as the nopals are regularly replanted, the process is almost entirely sustainable, producing only water and nopal waste, which can be used to fertilize other crops.

Finding sustainable ways to produce fuel while doing minimal damage to the environment is an important challenge for countries around the world.  In Mexico, harnessing the power of the prickly pear cactus is a unique and clever solution.

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Mexico’s ‘green gold’: The company powering cars with cactus juice

Photo, posted July 8, 2006, courtesy of Christian Frausto Bernal via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The American Bumblebee

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Pollinators, such as bees and bats, are vital for global food production.  They provide an ecological service that’s necessary for the reproduction of nearly 75% of the world’s flowering plants, including more than two-thirds of the world’s food crops.

Bumblebees are among the most important plant pollinators.  They pollinate many food crops, including apples, tomatoes, blueberries and legumes, as well as countless types of trees, shrubs, and wildflowers.  But researchers have documented declines in both the abundance and range of many bumblebee species.

The American bumblebee, which is native to North America, is one of them.  The species can currently be found in eastern Canada, throughout much of the Eastern United States, and much of Mexico. 

According to a new study led by York University and recently published in the Journal of Insect Conservation, the American bumblebee is critically endangered, and it faces imminent local extinction from Canada.  This is considered the highest and most at-risk classification before extinction. 

The researchers used data from three sources in their study: the Bumble Bee Watch (which is a citizen science project), the Bumble Bees of North America database (that has records dating back to the late-1800s), and their own field survey work.  They used the IUCN’s Red List assessment criteria to evaluate the status of the American bumblebee within its Canadian range.

The research team found that the species’ area of occurrence has decreased by approximately 70% and its relative abundance dropped by 89% from 2007-2016 when compared to 1907-2006. 

The American bumblebee can still be found throughout its Canadian range.  But immediate conservation action is desperately needed.  

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Disappearing bumblebee species under threat of extinction

Photo, posted August 22, 2011, courtesy of Rachel Elaine via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Wildlife And The Border Wall

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The border between the United States and Mexico is nearly 2,000 miles long, stretching from San Ysidro, California to Brownsville, Texas.  Discontinuous barriers currently cover approximately 650 miles of our southern border. As the particulars of how to better secure the remaining 1,350 miles of border are worked out, one thing is abundantly clear: extending physical barriers would negatively impact wildlife and the environment.

The Trump Administration has called for a 1,000-mile wall, which would cut across land that includes important habitats for wildlife.  According to an article signed by nearly 3,000 scientists, this plan would “threaten some of the continent’s most biologically diverse regions” by inhibiting species movement and triggering flooding. The paper, which was published in the journal Bioscience, highlights how more than 1,500 native animal and plant species would be affected by the wall, including 62 that are listed as endangered or vulnerable.

An extended border wall would not only impede movement of many wildlife species but it would also put pressure on creatures already in peril, such as the Mexican gray wolf and the Sonoran pronghorn.  Other at risk animals include the ocelot, black bear, and desert bighorn sheep. 

According to researchers, extending the border wall could cause problems for low-flying birds and insects. Even plants, including the endangered wildflower Zapata bladderpod and the threatened whiskerbush cactus, are particularly at risk.

According to a 2011 study, bird-watching and other forms of ecotourism in the Lower Rio Grande Valley brought in more than $344 million in economic activity and approximately 4,400 jobs. 

Preserving our natural heritage must be part of this national security discussion. 

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Nature Divided, Scientists United: US–Mexico Border Wall Threatens Biodiversity and Binational Conservation

Photo, posted December 14, 2014, courtesy of Tony Webster via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Major Investments In Solar Power

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There is big money going into renewable energy and energy-smart technologies and half of that is going into solar power.  In 2017, global investments in green energy reached $334 billion and $161 billion of that was in solar.

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More Fake Fish News

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There has been quite a bit of news in recent years about the mislabeling of fish sold in markets and restaurants.  One study a few years ago concluded that 1/3 of fish sold is not what it is labeled to be. Much of the practice is economic fraud:  substituting cheaper, easier-to-find fish for rarer, more valuable types.  For example, the study found that fish sold as red snapper was almost always not what it claimed to be.  But cheating paying customers is not the only problem associated with the misidentification of fish.

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Earthquake Warning System

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The destructive power of both hurricanes and earthquakes has made headlines in recent times.   The slow development of the hurricanes in the Atlantic was monitored for days before they wreaked havoc on Caribbean islands and Florida cities.  Earthquakes, on the other hand, occur suddenly and without warning.   Except, that isn’t entirely true.

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The Monarch Highway

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We have talked about the monarch butterfly on a number of occasions.  The population of these iconic orange and black butterflies in North America has plummeted from 1 billion to 33 million over the past 20 years.  People have undertaken a variety of efforts to try to save the species but now a major project to restore the dwindling habitat of the monarch is underway.

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Vanishing Vaquitas

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The world’s smallest porpoise – the vaquita – is in real trouble.  According to a recent report by the International Committee for the Recovery of the Vaquita (or CIRVA), the vaquita population has plummeted to just 30 individuals –a 90% plunge since 2011 – despite international conservation efforts.  The vaquita, which is found only in Mexico’s Upper Gulf of California, is the most endangered marine mammal on Earth and is on the doorstep of extinction.

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Is Coffee Endangered?

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There are many worries related to climate change, notably the increasing occurrence of extreme weather events, melting polar ice, rising seas, and so forth.  But perhaps one of the most ominous warnings comes from a new report issued by the Climate Institute about the future of coffee.

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Some Good News For Monarchs

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Spring is the time of the great monarch migration when the butterflies leave their wintering grounds in Mexico and head north to Canada.  As we have been saying for quite some time, fewer and fewer butterflies have been making the trek each year.  Twenty years ago, a billion monarchs swarmed the winter site in Mexico.  In 2013, the number was down to 33 million.

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Fir Trees And Butterflies

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We have done a number of stories about the sad state of the monarch butterfly and how their numbers have dropped from a billion to only 33 million as of a couple of years ago.  Biologists in the U.S. have been trying to restore the summer habitat of the butterflies by urging the planting of milkweed, which is the primary host plants for monarch butterfly caterpillars.

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Beware The Blob

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There has been plenty of discussion of El Niño, the periodic weather phenomenon in which prevailing easterly winds in the Pacific Ocean weaken, allowing warm water to move eastward and wreak havoc with the weather in North and South America.  The current El Niño is a particularly strong one; some say it may be one of the strongest ever and are calling it the “Godzilla El Niño.”

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