Category Archives: biodiversity

How Nuclear Explosions Affect the Deep Ocean

Radioactive carbon released into the atmosphere from 20th-century nuclear bomb tests has reached the deepest parts of the ocean, new research finds.  A new study in AGU’s journal Geophysical Research Letters finds the first evidence of radioactive carbon from nuclear bomb tests in muscle tissues of crustaceans that inhabit Earth’s ocean trenches, including the Mariana Trench, home to the deepest spot in the ocean.

Mariana Deep Ocean Trench

Organisms at the ocean surface have incorporated this “bomb carbon” into the molecules that make up their bodies since the late 1950s. Crustaceans in deep ocean trenches are feeding on organic matter from these organisms when it falls to the ocean floor. The results show human pollution can quickly enter the food web and make its way to the deep ocean, according to the study’s authors.


According to researchers, water containing carbon-14 can take centuries to circulate throughout the ocean, but the food web drastically accelerated the process. “There’s a very strong interaction between the surface and the bottom, in terms of biologic systems, and human activities can affect the biosystems even down to 11,000 meters,” said Weidong Sun, a coauthor of the study, “so we need to be careful about our future behaviors.”

AGU Press Release, 8 May 2019

Killing Popcupines for their Bellies: endangered species

Porcupines  are been hunted for undigested plant material in their gut known as bezoars.

Varieties of porcupine bezoar

According to leading wildlife trafficking experts, the small, spiny rodents are at risk of becoming endangered across Southeast Asia.  Demand is predominantly driven by China, where some believe that bezoars, which accumulate in the digestive tract, have potent medicinal properties, including the ability to cure diabetes, dengue fever, and cancer. Bezoars are sold either raw or in powdered form and may be processed into capsules. A few ounces of the substance can command hundreds, even thousands, of dollars. Most sought after is the dark red “blood” bezoar, believed to be the most potent of the several varieties. Prices for bezoars have “increased exponentially during the past few years, following recent claims of their cancer-curing properties,” according to a 2015 report by the wildlife trade monitoring organization Traffic.

The Philippine porcupine, the Asiatic brush-tailed porcupine, and the Malayan porcupine, which live throughout Southeast Asia, are all flagged as threatened and declining in number by the International Union for Conservation of Nature, the body that sets the conservation status of wildlife species. None has yet been listed as endangered, which would bolster legal protection and international awareness.

Excerpts from Porcupines are being poached for their stomach content, National Geographic, Mar. 22, 2019

How to Strengthen the Immune System of Plants: biodiversity

n the past 150 years, the concentration of carbon dioxide in the atmosphere has risen from 280 parts per million (ppm) to 410 ppm. For farmers this is mixed news. Any change in familiar weather patterns caused by the atmospheric warming this rise is bringing is bound to be disruptive. But more carbon dioxide means more fuel for photosynthesis and therefore enhanced growth—sometimes by as much as 40%. And for those in temperate zones, rising temperatures may bring milder weather and a longer growing season. (In the tropics the effects are not so likely to be benign.) What is not clear, though, and not much investigated, is how rising CO2 levels will affect the relation between crops and the diseases that affect them…

Plant biology is altered substantially by a range of environmental factors. This makes it difficult to predict what effect a changing climate will have on particular bits of agriculture. Carbon dioxide is a case in point. It enhances growth of many plants but,  it also shifts the defences to favour some types of disease over others.

To make matters even more complicated, evidence is mounting that changes in temperature and water availability also shift plant immune responses. André Velásquez and Sheng Yang He, at Michigan State University, wrote an extensive review on the warfare between plants and diseases in Current Biology in 2018. They noted that though some valuable crops, such as potatoes and rice, experience less disease as moisture levels increase, this is not the case for most plants. High humidity, in general, favours the spread of botanical diseases. The same can be said for temperature—with some diseases, like papaya ringspot virus, thriving in rising temperatures while others, for example potato cyst, are weakened.

The problems are daunting, then, but there is a way to try to solve them… Genes which grant resistance to diseases that might become severe in the future need to be tracked down. Modern crops have been streamlined by artificial selection to be excellent at growing today. This means that they have the genes they need to flourish when faced with the challenges expected from current conditions, but nothing more. Such crops are thus vulnerable to changes in their environment.  One way to find genes that may alter this state of affairs is to look to crops’ wild relatives. Uncossetted by farmers, these plants must survive disease by themselves—and have been fitted out by evolution with genes to do so. Borrowing their dna makes sense. But that means collecting and cataloguing them. This is being done, but not fast enough. The International Centre for Tropical Agriculture, a charity which works in the area, reckons that about 30% of the wild relatives of modern crops are unrepresented in gene banks, and almost all of the rest are underrepresented….

[This is becuase] most countries are, rightly, protective of their genetic patrimony. If money is to be made by incorporating genes from their plants into crops, they want to have a share of it. It is therefore incumbent on rich countries to abide by rules that enable poor ones to participate in seed collecting without losing out financially. Poor, plant-rich countries are in any case those whose farmers are most likely to be hurt by global warming. It would be ironic if that were made worse because genes from those countries’ plants were unavailable to future-proof the world’s crops.

Excerpts from Blocking the Road to Rusty Death: Climate Change and Crop Disease, Economist,  Apr. 20, 2019

Suing and Wining: Indigenous People, Ecuador

Hunter-gatherers in the Amazon sought in court on in April 2019 to stop Ecuador’s government auctioning their land to oil companies, as tension mounts over the future of the rainforest…The Waorani said the government did not properly consult them in 2012 over plans to auction their land to oil companies.

“We live on these lands and we want to continue to live there in harmony. We will defend them. Our fight is that our rights are respected,” said Nemonte Nenquimo, a leader of the 2,000-strong Waorani….Ecuador is pushing to open up more rainforest and develop its oil and gas reserves in the hope of improving its sluggish economy and cutting its high fiscal deficit and foreign debt…

The constitution gives the government the right to develop energy projects and extract minerals on any land, regardless of who owns it, but requires that communities are consulted first and are properly informed about any projects and their impact. Laws to regulate the consultation process have yet to be introduced – although the court case could push the government to do this, said Brian Parker, a lawyer with campaign group Amazon Frontlines, which is supporting the Waorani…

The government announced last year that it had divided swathes of forest up into blocs for auction, one of which – bloc 22 – covers the Waorani’s ancestral lands, raising the specter of pollution and an end to their way of life.  In two landmark cases in 2018, local courts sided with indigenous communities who said the government had failed to inform them before designating their land for mineral exploitation….The Inter-American Court of Human Rights also ruled in 2012 that Ecuador had violated its Sarayaku Amazonian community’s right to prior consultation before drillers started exploration on their lands in the late 1990s.

Excerpts Ecuador’s hunter-gatherers in court over oil drilling in Amazon, Reuters, Apr. 11, 2019

5,000 Eyes in the Sky: environmental monitoring

The most advanced satellite to ever launch from Africa will soon be patrolling South Africa’s coastal waters to crack down on oil spills and illegal dumping.  Data from another satellite, this one collecting images from the Texas portion of a sprawling oil and gas region known as the Permian Basin, recently delivered shocking news: Operators there are burning off nearly twice as much natural gas as they’ve been reporting to state officials.

With some 5,000 satellites now orbiting our planet on any given day…. They will help create a constantly innovating industry that will revolutionize environmental monitoring of our planet and hold polluters accountable…

A recent study by Environmental Defense Fund focused on natural gas flares from the wells in the Permian Basin, located in Western Texas and southeastern New Mexico. Our analysis proved that the region’s pollution problem was much larger than companies had revealed.  A second study about offshore gas flaring in the Gulf of Mexico, published by a group of scientists in the Geophysical Research Letters, showed that operators there burn off a whopping 40% of the natural gas they produce.

Soon a new satellite will be launching that is specifically designed not just to locate, but accurately measure methane emissions from human-made sources, starting with the global oil and gas industry.  MethaneSAT, a new EDF affiliate unveiled in 2018, will launch a future where sensors in space will find and measure pollution that today goes undetected. This compact orbital platform will map and quantify methane emissions from oil and gas operations almost anywhere on the planet at least weekly.

Excerpts from Mark Brownstein, These pollution-spotting satellites are just a taste of what’s to come, EDF, Apr. 4, 2019

Assisted Evolution: Engineering Coral Reefs

Imagine ecologists cultivating whole new breeds of trees to restock a devastated wilderness…. Coral conservation has traditionally focused on minimizing damage from insults such as water pollution, invasive starfish, and destructive fishing or tourism. In the Caribbean, some conservationists have worked to “replant” damaged coral. But Gates and Van Oppen [two scientists]  have something more intrusive in mind. They want to try to alter the genetics of coral or the microbes that live on it. They dubb the effort “assisted evolution.”

Coral’s most remarkable characteristic—being an animal that is part plant—is also its Achilles’ heel in a hotter world. Normally, coral polyps—the individual coral organisms, which resemble a sea anemone the size of a pinhead—live in harmony with their algal partners, which help feed the polyps and give corals their bright colors. But during heat waves, the relationship sours. Overheated polyps perceive the algae as an irritant and eject them like unwanted squatters. The coral is left bleached, bone-white and starving. If the heat persists, the coral won’t take in new algae and can die.  The bond between coral and algae is complicated, however, and still not fully understood. Just 25 years ago, for example, researchers believed that coral housed just one variety of symbiotic algae. Now, they have identified hundreds. And they are just beginning to examine the role played by the coral’s microbiome, the menagerie of bacteria that inhabit a coral polyp.

Coral bleaching right.

But the complexity also offers multiple paths for scientists trying to forge a less fragile bond between coral and algae. Today, four major lines of research exist: One involves cross-breeding corals to create heat-tolerant varieties, either by mixing strains within a species or by crossing two species that would not normally interbreed. The second enlists genetic engineering techniques to tweak coral or algae. A third tries to rapidly evolve hardier strains of coral and algae by rearing them for generations in overheated lab conditions. A fourth approach, the newest, seeks to manipulate the coral’s microbiome…

In 2018, Cleves [scientist] became the first to report successfully using the CRISPR-Cas9 gene-editing tool on coral. CRISPR is often touted as a method for making genetically modified species. But Cleves says he isn’t interested in creating new kinds of coral. Rather, he sees CRISPR as a tool for deciphering the inner workings of coral DNA by knocking out, or disabling, genes one by one. He hopes to identify genes that might serve as “master switches” controlling how coral copes with heat and stress—knowledge that could help researchers quickly identify corals in the wild or in the laboratory that are already adapted to heat.

Either way, such efforts to re-engineer coral reefs make people such as David Wachenfeld, chief scientist for the Great Barrier Reef Marine Park Authority here, uneasy. The authority is supposed to protect the reef and regulate activities there. In the past, that meant a hands-off approach. Now, he concedes that “it is almost inconceivable that we’re not going to need these tools.” But, he adds, “That doesn’t mean I’m happy about any of this. This is crisis management.”

He ticks off a list of potential difficulties. Scientists focused on breeding heat-loving coral have to avoid weakening other key traits, such as coping with cold. Introducing a new coral on the scale needed to make a dent on a network of 2900 reefs spanning an area half the size of Texas is a daunting challenge. Even in its damaged state, the Great Barrier Reef still contains hundreds of millions of corals—enough to swamp the genetic impact of new coral species…

Could some kind of “super coral,” as some researchers have dubbed them, also run amok in delicate coral ecosystems.

Excerpts from  The Reef Builders, Science, Mar. 22, 2019

Biodiversity and Respect for Human Rights

The instinctive response of many environmentalists  is to to fence off protected areas as rapidly and extensively as possible. That thought certainly dominates discussions of the Convention on Biological Diversity, the main relevant international treaty. An eight-year-old addendum to the pact calls for 17% of the world’s land surface and 10% of the ocean’s water column (that is, the water under 10% of the ocean’s surface) to be protected by 2020. Currently, those figures are 15% and 6%. Campaigners want the next set of targets, now under discussion, to aim for 30% by 2030—and even 50% by 2050. This last goal, biogeographers estimate, would preserve 85% of life’s richness in the long run.  As rallying cries go, “Nature needs half” has a ring to it, but not one that sounds so tuneful in the poor countries where much of the rhetorically required half will have to be found. Many people in such places already feel Cornered by Protected Areas.” (See also Biodiversity and Human Rights)

James Watson, chief scientist at the Wildlife Conservation Society (wcs), another American charity, has an additional worry about focusing on the fence-it-off approach. If you care about the presence of species rather than the absence of humans, he warns, “‘nature needs half’ could be a catastrophe—if you get the wrong half.” Many terrestrial protected areas are places that are mountainous or desert or both. Expanding them may not translate into saving more species. Moreover, in 2009 Lucas Joppa and Alexander Pfaff, both then at Duke University in North Carolina, showed that protected areas disproportionately occupy land that could well be fine even had it been left unprotected: agriculture-unfriendly slopes, areas remote from transport links or human settlements, and so on. Cordoning off more such places may have little practical effect.

Southern Appalachians, Virginia. image from wikipedia

 In the United States it is the underprotected southern Appalachians, in the south-east of the country, that harbour the main biodiversity hotspots. The largest patches of ring-fenced wilderness, however, sit in the spectacular but barren mountain ranges of the west and north-west. In Brazil, the world’s most speciose country, the principal hotspots are not, as might naively be assumed, in the vast expanse of the Amazon basin, but rather in the few remaining patches of Atlantic rainforest that hug the south-eastern coast.

Deforestation Atlantic Rainforest in Rio de Janeiro. Image from wikipedia

Nor is speciosity the only consideration. So is risk-spreading. A team from the University of Queensland, in Australia, led by Ove Hoegh-Guldberg, has used a piece of financial mathematics called modern portfolio theory to select 50 coral reefs around the world as suitable, collectively, for preservation. Just as asset managers pick uncorrelated stocks and bonds in order to spread risk, Dr Hoegh-Guldberg and his colleagues picked reefs that have different exposures to rising water temperatures, wave damage from cyclones and so on. The resulting portfolio includes reefs in northern Sumatra and the southern Red Sea that have not previously registered on conservationists’ radar screens…

Another common finding—counterintuitive to those who take the “fence-it-all-off” approach—is that a mixed economy of conservation and exploitation can work. For example, rates of deforestation in a partly protected region of Peru, the Alto Mayo, declined by 78% between 2011 and 2017, even as coffee production increased from 20 tonnes a year to 500 tonnes.

Environmental groups can also draw on a growing body of academic research into the effective stewardship of particular species. For too long, says William Sutherland, of Cambridge University, conservationists have relied on gut feelings. Fed up with his fellow practitioners’ confident but unsubstantiated claims about their methods, and inspired by the idea of “evidence-based medicine”, he launched, in 2004, an online repository of relevant peer-reviewed literature called Conservation Evidence.  Today this repository contains more than 5,400 summaries of documented interventions. These are rated for effectiveness, certainty and harms. Want to conserve bird life threatened by farming, for example? The repository lists 27 interventions, ranging from leaving a mixture of seed for wild birds to peck (highly beneficial, based on 41 studies of various species in different countries) to marking bird nests during harvest (likely to be harmful or ineffective, based on a single study of lapwing in the Netherlands). The book version of their compendium, “What Works in Conservation”, runs to 662 pages. It has been downloaded 35,000 times.

Excerpts from How to preserve nature on a tight budget, Economist, Feb. 9, 2919