Tag Archives: pacific

Arsenic.

There are arsenic-breathing microbes in the tropical Pacific, a new study finds

Arsenic is generally viewed as a life-ending element, but new research shows how some organisms rely on it to breathe.

Arsenic.

Image credits fdecomite / Flickr.

Certain microorganisms in the Pacific Ocean respire arsenic, according to a new study from the University of Washington. The findings are quite surprising as, although arsenic-based respiration has been documented in ancient and current organisms, it is extremely rare on the planet. Moreover, ocean water just doesn’t have that much arsenic, to begin with.

Doing without

“We’ve known for a long time that there are very low levels of arsenic in the ocean,” said co-author Gabrielle Rocap, a UW professor of oceanography. “But the idea that organisms could be using arsenic to make a living—it’s a whole new metabolism for the open ocean.”

The team analyzed Pacific seawater samples taken from water layers at depth intervals where oxygen is almost absent. Given the lack of oxygen here, organisms had to adapt and seek other sources of energy, the team writes. The results are interesting and may become very important in our understanding of marine ecosystems, as these areas — known as oxygen-deficient zones, ODZs or oxygen minimum zones, OMZs — will likely expand under climate change, according to other recent research.

The most common alternatives to oxygen that biology draws upon today are nitrogen and sulfur. However, previous research carried out by Jaclyn Saunders, this paper’s first author, suggested that arsenic might also do the trick. She was curious to see whether this was the case, which spurred the present paper.

The samples used in this study were collected during a 2012 research cruise to the tropical Pacific, off the coast of Mexico. Analysis of eDNA material recovered from the samples showed two genetic pathways that process arsenic-based molecules to extract energy. Two different forms of arsenic seem to be targeted by these pathways, leading the authors to believe that we’re looking at two organisms that cycle arsenic back and forth between the different forms. Which, as far as ecosystems are concerned, is quite a nifty trick.

“Thinking of arsenic as not just a bad guy, but also as beneficial, has reshaped the way that I view the element,” said Saunders, who did the research for her doctoral thesis at the UW and is now a postdoctoral fellow at the Woods Hole Oceanographic Institution and the Massachusetts Institute of Technology.

While arsenic might be beneficial, it’s certainly not very popular. Only about 1% of the microbe population in the samples seems to breathe arsenic, judging by the ratios of genetic material. Most likely, these strains are loosely-related to arsenic-breathing microbes found in hot springs or contaminated sites on land. Saunders recently collected samples from the same region and is now trying to grow the arsenic-breathing marine microbes in a lab in order to study them more closely.

“Right now we’ve got bits and pieces of their genomes, just enough to say that yes, they’re doing this arsenic transformation,” Rocap said. “The next step would be to put together a whole genome and find out what else they can do, and how that organism fits into the environment.”

“What I think is the coolest thing about these arsenic-respiring microbes existing today in the ocean is that they are expressing the genes for it in an environment that is fairly low in arsenic,” Saunders said. “It opens up the boundaries for where we could look for organisms that are respiring arsenic, in other arsenic-poor environments.”

Arsenic respiration is most likely a ‘retro’ type of respiration, passed down over the eons. When life first sprung up on Earth, oxygen was very scarce both in the air and in the ocean (as oxygen is very reactive and forms chemical bonds readily). Until photosynthesizing plants became widespread, there simply wasn’t enough output of this gas to maintain any meaningful levels available for organisms to use up. As such, early life had to use something else for energy — and arsenic was likely common in the oceans at that time.

Climate change may, sadly, breathe new life into arsenic-breathing life. Low-oxygen regions are projected to expand as thermal imbalances shift water currents, and dissolved oxygen is also predicted to drop across the board in marine environments.

The paper “Complete arsenic-based respiratory cycle in the marine microbial communities of pelagic oxygen-deficient zones” has been published in the journal Proceedings of the National Academy of Sciences.

Great Garbage Patch.

The Pacific Garbage patch is 16 times bigger than we thought

The Great Pacific Garbage Patch is a lot bigger than we’ve estimated — and more dangerous in composition.

Great Garbage Patch.

A map showing the Great Pacific Garbage Patch (GPGP) floating in the ocean, and trash concentration levels in the gyre.
Image credits The Ocean Cleanup Foundation.

Out on the waves of the Pacific Ocean lies one of man’s greatest accomplishments. I use the last term in the loosest way possible since, by ‘great’, I mean sheer size; the aptly named Great Pacific Garbage Patch now measures a stunning 620,000 square miles (roughly 1,605,800 square km) — some 16 times larger than previously estimated.

Resting between California and Hawaii, in an area known as the Pacific gyre, the Patch has been steadily growing in current-borne plastics; and it has grown fat indeed — it now contains some 87,000 tons of plastic, a new study reports. The authors note that with the massive deluge of plastic pollution we’re generating, this Patch is growing right as we speak, and will likely keep doing so. Data gathered between 1970 and 2015 shows the plastic levels in the garbage patch are increasing at a faster rate than in surrounding waters.

Patches of Plastics

As far as huge spans of thrash are concerned, the Patch is very cosmopolitan — microplastics stew alongside larger bits of plastics, all entangled in fishing nets and gear. But, worryingly, the largest chunk of all this ‘ew’, some 46%, is made up of fishing nets, the authors report. Other types of commercial fishing gear, such as eel traps, ropes, or oyster spacers account for a majority of the rest of the trash.

The findings are part of a three-year mapping effort involving Ocean Cleanup, an international team of scientists, six universities and an aerial sensor company. They used two aircraft surveys and 30 vessels to cross the debris field and get an accurate idea of its size and composition.

“I knew there would be a lot of fishing gear, but 46 percent was unexpectedly high,” said Laurent Lebreton, member of the Ocean Cleanup Foundation. “Initially, we thought fishing gear would be more in the 20 percent range. That is the accepted number [for marine debris] globally – 20 percent from fishing sources and 80 percent from land.”

Having a lot of fishing equipment lying about in the middle of the ocean is quite a poor development; all this refuse can entangle turtles, seals, and whales; plastic items kill or injure some 100,000 marine animals each year, National Geographic reports.

Despite the gloomy outlook, the team says there are still many unknowns in regard to this garbage patch: how polluted are deeper waters? How much plastic has sunk to the sea floor? More research will have to answer these questions.

The paper “Evidence that the Great Pacific Garbage Patch is rapidly accumulating plastic” has been published in the journal Scientific Reports.

The crater lake from the summit rim at the center of Hunga Tonga-Hunga Ha’apai. Credit: NASA.

A newly formed island in the Pacific might resemble Martian volcanoes

The crater lake from the summit rim at the center of Hunga Tonga-Hunga Ha’apai. Credit: NASA.

The crater lake from the summit rim at the center of Hunga Tonga-Hunga Ha’apai. Credit: NASA.

In the last days of 2014, something incredible happened — a whole new island was born, right before our eyes. For weeks, an underwater volcano that had been spewing ash and lava into the Pacific settled into a brand new island, rising 120 meters (400 feet) above the ocean’s surface. Geologists reckoned it wouldn’t be more than a couple of months before the island would succumb to erosion. Today, three years later, it’s still there. Scientists now estimate a far longer lifespan for the island of Hunga Tonga-Hunga Ha’apai, as it was unofficially christened, which could live on for six to 30 years. What’s more, its formation could lend valuable clues as to how similar underwater volcanoes erupted on Mars during its wet past, billions of years ago.

Baby islands and ancient alien volcanoes

Most islands on Earth were formed by underwater volcano eruptions. The story of a volcanic island starts inside the planet. Earth has an inner core made of solid metal. It is thought to be as hot as the surface of the sun! A liquid outer core, also made of metals, surrounds the inner core. It is liquid because it is under less pressure than the inner core. Around the outer core is the Earth’s mantle. It’s made of hot rock called magma which is mostly solid,  but can flow like hot plastic. The last layer of the Earth, the crust, is where we live. It is the thin, outside layer of the Earth. The crust is made of pieces that fit together, like a jigsaw puzzle, called tectonic plates. Forces caused by Earth’s heat sometimes push them tighter against each other. Sometimes forces pull them apart. And sometimes there are weak spots in the crust. When plates pull apart or there is a weak spot, the mantle’s hot, flowing magma oozes out.

That’s how you get a volcano and these can be found all over Earth. Many of them are on land, but most volcanoes are actually found under the surface of the oceans. If an underwater volcano keeps erupting, it can rise above the ocean’s surface. An island is formed. Iceland formed millions of years ago from underwater volcanic eruptions, for instance.

Satellite-derived elevations of the island in April 2015 (left) and September 2017 (right). Credit: NASA.

Satellite-derived elevations of the island in April 2015 (left) and September 2017 (right). Credit: NASA.

A map showing a large scale view of the South Pacific with the Kingdom of Tonga highlighted in purple. (Main map) Hunga Tonga and Hunga Ha’apai lie on the rim of a submarine caldera located 65 km N of a wharf in the harbor at Nuku’alofa, Tongatapu island (the main island of the archipelago). Credit: USGS.

A map showing a large scale view of the South Pacific with the Kingdom of Tonga highlighted in purple. (Main map) Hunga Tonga and Hunga Ha’apai lie on the rim of a submarine caldera located 65 km N of a wharf in the harbor at Nuku’alofa, Tongatapu island (the main island of the archipelago). Credit: USGS.

Hunga Tonga Hunga Ha’apai rises about a mile above the deep ocean floor, making the water around the island shallow. At the recent American Geophysical Union, scientists at NASA’s Goddard Space Flight Center said that perhaps similar features existed around the Martian volcanoes. As such, Hunga Tonga Hunga Ha’apai might prove to be a perfect geological test tube that could help us understand better the water environment on early Mars.

“We see things that remind us of this kind of volcano at similar scales on Mars,” said Dr. Garvin, the chief scientist at NASA’s Goddard Space Flight Center in Greenbelt, Md. “And literally, there are thousands of them, in multiple regions.”

Since the new Tongan island formed, researchers have been closely studying satellite imagery, allowing them to generate detailed maps of the shifting topography. Such islands are usually short-lived, quickly succumbing to eroding waves. Hunga Tonga-Hunga Ha’apai was initially oval but then its southern shore eroded rapidly, creating a direct corridor for the Pacific Ocean to break into the lake at the center of the tiny island. It looked like the island was about to vanish. But then a sandbar formed which yet again sealed the lake, stabilizing the landscape.

Hunga Tonga-Hunga Ha’apai got lucky. When conditions are just right, warm water can cement volcanic ash into rock, and this may be what happened on the island. It’s only the third island in the last 150 years that has survived for more than a few months. According to their most recent study, Garvin and colleagues estimate the island could last for decades.

What the researchers plan on doing next is to connect time-lapse photography of the island with the erosional cycle at different depths. This way, they’ll have a sequence to look for on Mars. If the next rover catches a glimpse of some of these features on Mars, scientists could then infer how deep the water was there and for how long to do the same erosional work.

 

 

 

Henderson Island was once regarded as one of the most pristine landscapes in the world. This makes this desolate sight from Henderson even more hurtful. Every day, some 27 new pieces of junk wash up on the island according to a new study. Credit: Jennifer Lavers/University of Tasmania.

Remote Island in the middle of the Pacific is the most plastic-littered place on Earth

Henderson Island was once regarded as one of the most pristine landscapes in the world. This makes this desolate sight from Henderson even more hurtful. Every day, some 27 new pieces of junk wash up on the island according to a new study. Credit: Jennifer Lavers/University of Tasmania.

Henderson Island was once regarded as one of the most pristine landscapes in the world. This makes this desolate sight from Henderson even more hurtful. Every day, some 27 new pieces of junk wash up on the island according to a new study. Credit: Jennifer Lavers/University of Tasmania.

Thousands of miles away from the nearest city, smack in the middle of the South Pacific Ocean, lies the Henderson Island. This island, part of the Pitcairn Islands and a UNESCO World Heritage Site, has never been permanently inhabited and only a few humans have ever made the trip by ship to set foot on it, usually scientists on research expeditions. Knowing this, Henderson ought to be one of the most pristine places on this planet. The sad reality, however, is that Henderson Island has the highest density of plastic trash ever reported in nature.

No escaping plastic pollution

“What’s happened on Henderson Island shows there’s no escaping plastic pollution even in the most distant parts of our oceans,” lead author Jennifer Lavers from the University of Tasmania said in a statement. “Far from being the pristine ‘deserted island’ that people might imagine of such a remote place, Henderson Island is a shocking but typical example of how plastic debris is affecting the environment on a global scale.”

According to the University of Tasmania team, huge quantities of plastic waste in all shapes and sizes have washed up along the years on Henderson. Every day, thousands of new tiny bits of plastic are thrown by tides on the white-sand beaches of the island.

Henderson Island is polluted with the greatest density of plastic in the world. The situation is so bad that hermit crabs use plastic debris for homes. Credit: Jennifer Lavers/University of Tasmania.

Henderson Island is polluted with the greatest density of plastic in the world. The situation is so bad that hermit crabs use plastic debris for homes. Credit: Jennifer Lavers/University of Tasmania.

For three months since May 2015, Lavers and colleagues lived on Henderson Island and documented all of the man-made trash there. Their estimates suggest there are over 37,661,395 pieces of anthropogenic trash which amount to 17.6 tons of plastic waste. This mass, however, represents only “1.98 seconds’ worth of the annual global production of plastic,” researchers wrote in the Proceedings of the National Academy of Science.

These stats are extremely worrisome and scary for a number of reasons. The report gives to show there’s no escaping human influence, i.e. trash, even in the remotest places on Earth. The oceans, like the land and atmosphere, is a unified environment which is why trash from San Francisco can wind up in the ocean and, eventually guided by currents, on a remote island such as Henderson. By some estimates, there may be some 5 trillion pieces of plastics and microplastics swirling around the world’s oceans. These wash up on shores across the planet where they litter and pollute the environment. Animals, both marine and land-based, eat these plastics causing them to suffer or die. Ultimately, humans can end up ingesting these plastics too since we’re at the top of the food chain.

Most of the items found on Henderson were largely disposable or single-use; things like razors, cigarette lighters, toothbrushes, etc. All of this trash doesn’t bode well with the island’s unique ecology, which includes ten endemic plant and four bird species. The image above with the hermit crab that uses a plastic container for a shell is most telling in this respect.

So, who’s to blame? Everyone basically. The paper doesn’t explicitly say this, but the millions of plastic debris on Henderson come from all over the world.

Thick smog engulfs Beijing.

Asian pollution drives storms in the Pacific

While pollution is most felt locally, where its produced, some of it eventually winds up in remote locations proving to be a global hazard even places in the world where there isn’t any kind of fossil industry. For instance, a while ago I reported how 29% of San Francisco’s pollution comes from China – be you didn’t know that. Air pollution from China and other heavy burning Asian countries travel through the Pacific on their way to mainland North America. Apparently, these pollutants are strengthening storms above the Pacific Ocean, which feeds into weather systems, thus posing a significant threat.

China is one of the most polluted countries in the world. It’s enough to look at their most populous and most industrialized city, Beijing to get an idea. Here, smog can get so thick that most of the time you can’t see the sun directly from ground level; other times, smog intensifies so much that cars can’t run anymore and people need to be off the streets. The local government reports an air quality index (AQI) of 500, the highest possible reading – basically, the pollution is so high it’s off the charts. Knowing this, it’s no surprise that life expectancy is cut by 15 years for those living with the smog.

Pollution intensifies storms in the Pacific, and elsewhere

Things are rough, no doubt about it, and the government is making steps to curve the smog and pollution, but in the face of massive and rapid industrialization of the whole country, there’s no chance they’ll pollute any less than now. When pollution is concerned, this isn’t a problem that affects China alone – it becomes a global peril.

Yuan Wang and team at the Jet Propulsion Laboratory at the California Institute of Technology have gathered important evidence that suggests East Asian pollution is moving further afield. These were reached after the researchers performed computer models of the effects Asian pollution might have on weather systems.

The tiny polluting particles interact with water droplets in the air above the North Pacific and cause clouds to grow denser, resulting in more intense storms above the ocean. What this means is that global climate is becoming threatened by this sort of pollution and the effects of them are only recently beginning to be understood.

Dr Yuan Wang said: “Since the Pacific storm track is an important component in the global general circulation, the impacts of Asian pollution on the storm track tend to affect the weather patterns of other parts of the world during the wintertime, especially a downstream region [of the track] like North America.”

Commenting on the study, Professor Ellie Highwood, a climate physicist at the University of Reading, said: “We are becoming increasingly aware that pollution in the atmosphere can have an impact both locally – wherever it is sitting over regions – and it can a remote impact in other parts of the world. This is a good example of that.

The study is published in the Proceedings of the National Academy of Sciences (PNAS).