sensitive

Lots of female turtles

November 3, 2023 By EarthWise Leave a Comment

Green sea turtles were listed under the Endangered Species Act in 1978. Since that time, there have been conservation measures put in place in many locations. One such place is Florida, where restrictions on beachfront development and careful monitoring of turtle nests has helped to get hatchlings safely into the water. A gill net ban in 1995 sharply reduced the number of young turtles killed by fishing gear.

All of this has resulted in what is described as an explosion in turtle populations in Florida. Volunteers monitoring the 2023 nesting season on Florida’s beaches have counted more than 74,000 nests. That beats the previous record – set in 2017 – by an incredible 40%.

Unfortunately, this does not represent a guaranteed great future for the species. Sea turtles are particularly sensitive to the warming climate. The sex of a baby sea turtle is not determined by DNA, but rather by the temperature of the sand in which its egg develops. Cooler temperatures mean more males; warmer ones mean more females.

In recent years, the proportion of male green sea turtles has dwindled substantially. In the past few seasons, between 87 percent and 100 percent of the hatchlings tested in Florida have been female.

In the short term, the skewed sex ratio might be a boon for the species. Lots of females laying lots of eggs means lots of turtles. Sea turtles don’t reach sexual maturity until their twenties or thirties. So, for the next few decades, there are likely to be growing numbers of turtle nests. But down the line, there is going to be a real problem. Where will for all the female turtles find the mates to populate the species in the future?

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Florida Turtle Nests Are Recovering. When They Hatch, Expect Mostly Girls.

Photo, posted October 5, 2011, courtesy of Keenan Adams / USFWS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Air Pollution And Insects | Earth Wise

September 7, 2023 By EarthWise Leave a Comment

Insects can be found in every environment on Earth and play critical roles in the planet’s ecosystems. Insects pollinate more than 80% of plants, including those that we eat and those that provide food and habitat for other species. Without insects, we wouldn’t have the rich biodiversity that supports life on earth today.

But the world is experiencing a decline in overall insect populations as well as a collapse in insect diversity. According to researchers from the University of Melbourne in Australia, Beijing Forestry University in China, and the University of California – Davis, air pollution particles may be the cause of the dramatic decline. They found that an insect’s ability to find food and a mate is reduced when their antennae are contaminated by particulate matter.

In the study, which was recently published in the journal Nature Communications, the research team exposed houseflies to varying levels of air pollution for just 12 hours and then placed the flies in a Y-shaped tube ‘maze’. Uncontaminated flies typically chose the arm of the Y-maze leading to a smell of food or sex pheromones, while contaminated flies selected an arm at random, with 50:50 probability.

Using a scanning electron microscope, the researchers also found that as air pollution increases, more particulate material collects on the sensitive antennae of houseflies.

Insect antennae have olfactory receptors that detect odor molecules emanating from a food source, a potential mate, or a good place to lay eggs. If an insect’s antennae are covered in particulate matter, a physical barrier is created between the smell receptors and air-borne odor molecules.

Air pollution poses a significant threat to insect populations around the world.

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Air pollution particles may be cause of dramatic drop in global insect numbers

Photo, posted June 13, 2008, courtesy of Allen Watkin via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Sea Level Rise And Global Security | Earth Wise

March 22, 2023 By EarthWise Leave a Comment

Recently, United Nations General Secretary Antonio Guterres addressed the U.N. Security Council on the issue of the security threats created by rising sea levels. In the past, some members of the Security Council – notably Brazil, China, Russia, and at times, India – have argued that the U.N.’s climate program should address such issues and that the Security Council doesn’t have a mandate or the expertise to consider the issue. The underlying problem is that by addressing the security issues created by rising seas, other sensitive geopolitical issues might come to the forefront.

Guterres’ speech focused on the real possibility that rising seas could disrupt and destabilize global societies unless there is an organized international effort to get ahead of the problem. Major cities facing serious impacts from rising seas include Cairo, Lagos, Bangkok, Jakarta, Mumbai, Shanghai, Copenhagen, London, Los Angeles, New York, and Buenos Aires, among others.

In all, Guterres said that the danger is most acute for about 900 million people living in low-lying coastal areas. Some countries, particularly small island developing countries, could disappear entirely.

The world is already facing refugee crises related to politics, warfare, and extreme weather. The flood of refugees created by rising seas could be biblical in magnitude.

The confluence of climate change and global security is growing steadily. As the global body primarily responsible for maintaining international peace and security, the U.N. Security Council cannot duck this issue much longer. It has a critical role to play in building the political will required to address the security challenges looming from rising seas.

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Sea Level Rise Could Drive 1 in 10 People from Their Homes, with Dangerous Implications for International Peace, UN Secretary General Warns

Photo, posted July 19, 2021, courtesy of Face of the World via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Tracking Small-Scale Fishers | Earth Wise

October 4, 2022 By EarthWise Leave a Comment

About half of all global seafood is caught by artisanal fishers. These are individuals who operate on a small scale – often on a subsistence level – and typically fish only a short distance from shore. Over 85% of the estimated 2.5 million motorized fishing vessels in the world are less than 12 meters in length. Compared with large-scale commercial fishing operations, these enterprises are very small. However, they are essential to the food security and livelihoods of their communities. Because of their sheer numbers, artisanal fishers are an important sector to monitor, manage, and advocate for. They may be small-scale, but their importance and impact are huge.

Large ships make use of vessel tracking systems, which were originally conceived to prevent maritime collisions. Over time, VTS technology has become useful for other purposes including monitoring fishing activity in sensitive marine areas and looking out for forced labor on the high seas.

Among small fishing vessels, only an estimated 0.4% are equipped with VTS technology. So, a massive number of vessels accounting for a big part of the global catch cannot be monitored.

Researchers at UC Santa Barbara surveyed hundreds of artisanal fishers in Indonesia and Mexico to see if they were willing to pay to participate in a VTS program, or participate for free, or be paid to participate. Having the equipment would provide multiple benefits to the fishers including increased safety and better fisheries management. Two-thirds of the survey participants said they were willing to pay for the technology. The study is the first effort to explore the potential for encouraging wide adoption of VTS technology among artisanal fishers.

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Tracking Small-Scale Fishers

Photo, posted November 30, 2014, courtesy of Bernard Spragg via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The Bitter Truth About Caffeine

January 7, 2019 By EarthWise Leave a Comment

Black coffee has a bitter taste. Bitterness evolved as a natural warning system to protect the body from harmful substances. By the logic of evolution, we should therefore want to spit coffee out, but obviously it doesn’t work that way.

Caffeine itself has a particularly bitter taste. Surprisingly, a new study at Northwestern University has found that the more sensitive people are to the bitter taste of caffeine, the more coffee they drink. That sensitivity is actually a genetic variant.

So, one would think that people who are especially sensitive to the bitter taste of caffeine would drink less coffee. The counter intuitive result suggests that coffee consumers acquire a taste or an ability to detect caffeine as a result of the learned positive reinforcement (in other words, the buzz) elicited by caffeine. People with a heightened ability to taste coffee’s bitterness learn to associate good things with it.

The study also found in contrast that people sensitive to the bitter flavor of a different compound called 6-n-propylthiouracil (known as PROP)avoided coffee as well as red wine.

The study made use of applied Mendelian randomization, a technique commonly used in disease epidemiology, to test the causal relationship between bitter taste and beverage consumption in more than 400,000 men and women in the United Kingdom.

These results shed some light on the disdain many coffee drinkers have for decaf coffee. It may not be just the lack of buzz that turns them off. Some of them with the right genes may be missing that extra bit of bitterness that alerts them that something good is about to happen.

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Why we shouldn’t like coffee, but we do

Photo, posted May 22, 2009, courtesy of Olle Svensson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Glacial Engineering

October 24, 2018 By EarthWise Leave a Comment

As the world struggles with trying to limit carbon emissions and slow the pace of global warming, there is increasing analysis of various forms of geoengineering. Often, these consist of nearly unthinkable efforts to intervene in the climate on a global scale with unpredictable and possibly catastrophic consequences.

[Read more…] about Glacial Engineering