Tag Archives: plankton

Submersible robots help us better understand ocean health and carbon flows

Floating robots could become indispensable in helping us monitor the health of ocean ecosystems and the flow of carbon between the atmosphere and oceans, according to a new study.

Although the microscopic marine plants and animals which make up plankton are the bedrock of ocean ecosystems. While they’re essential for the well-being of everything that swims, they’re also very important for our comfort and well-being, too. Plankton is one of the largest single sources of oxygen on the planet, and it consumes a lot of CO2 to do it. This process is known as marine primary productivity.

Knowing how they’re faring, then, would be a great help. Floating robots can help us out in that regard, according to a new paper.

Floats my boats

“Based on imperfect computer models, we’ve predicted primary production by marine phytoplankton will decrease in a warmer ocean, but we didn’t have a way to make global-scale measurements to verify models. Now we do,” said Monterey Bay Aquarium Research Institute (MBARI) Senior Scientist Ken Johnson, first author of the paper.

Together with former MBARI postdoctoral fellow Mariana Bif, Johnson shows how a fleet of marine robots could completely change our understanding of primary productivity on a global scale. Data from these crafts would allow researchers to more accurately model the flow of carbon between the atmosphere and the ocean, thus improving our understanding of the global carbon cycle.

Furthermore, the duo explains, shifts in phytoplankton productivity can have significant effects on all life on Earth by changing how much carbon oceans absorb, and by altering oceanic food webs. The latter can easily impact human food security, as the oceans are a prime source of food for communities all over the world. In the context of our changing climate, it’s especially important to know with accuracy how much carbon plankton can scrub out of the atmosphere, and what factors influence this quantity.

Part of what makes the ocean such a good carbon sink is that dead organic matter sinks to the bottom. Plankton grows by consuming atmospheric oxygen, and is in turn consumed by other organisms, such as fish. As these eventually die, they sink to the bottom of the sea, where they’re decomposed by bacteria, releasing carbon in the process. However, because this happens at great depths, the carbon is effectively prevented from returning to the atmosphere for very long periods of time. Generally, it seeps into deep-water sediments and stays there for millions of years or more.

That being said, this process is very sensitive to environmental factors such as changes in climate. While we understand that this happens, we’ve not been able to actually monitor how primary productivity is responding to climate change on a global scale, as most of it happens in the depths of the oceans.

“We might expect global primary productivity to change with a warming climate,” explained Johnson. “It might go up in some places, down in others, but we don’t have a good grip on how those will balance.”

“Satellites can be used to make global maps of primary productivity, but the values are based on models and aren’t direct measurements,”

Autonomous robots could help us get the data we need, the study argues. For starters, it’s much easier to build robots that can withstand the humongous pressures of the deep ocean than it is to build equivalent manned submarines. Secondly, robots are mass-producible for relatively little cost. Human crews are expensive and slow to train — they’re also quite limited in availability. Finally, robots can operate for much longer periods of time than human crews, and nobody needs to risk their life in the process.

The authors point to the deployment of Biogeochemical-Argo (BGC-Argo) floats across the globe as a great example of how robots can help monitor primary productivity. These automated floats can measure temperature, salinity, oxygen, pH, chlorophyll, and nutrient content in marine environments, at depths of up to 2,000 meters (6,600 ft). A float can perform its monitoring tasks autonomously, shifting between different depths and supplying live data to researchers onshore. These robots have been deployed in increasing numbers over the past decade, providing reliable — but as of yet, still sparse — measurements of oxygen production across the globe.

Although the data they’ve been feeding us didn’t tell us anything new, it is the first time we’ve been able to quantitatively measure primary productivity directly.

“Oxygen goes up in the day due to photosynthesis, down at night due to respiration—if you can get the daily cycle of oxygen, you have a measurement of primary productivity,” explained Johnson.

In order to confirm that these robots were actually performing their job reliably, the team compared primary productivity estimates computed from the BGC-Argo floats to ship-based sampling data in two regions: the Hawaii Ocean Time-series (HOT) Station and the Bermuda Atlantic Time-series Station (BATS). The data from these two sources matched over several years, proving the reliability of the system.

“We can’t yet say if there is change in ocean primary productivity because our time series is too short,” cautioned Bif. “But it establishes a current baseline from which we might detect future change. We hope that our estimates will be incorporated into models, including those used for satellites, to improve their performance.”

Seeing as we have drones flying about the atmosphere taking pictures of everything and anything, it only makes sense that we’d eventually have some doing the same underwater. I am personally very thrilled to see robots taking on the deepest depths. The ocean is a fascinating place, but I’m also terrified of drowning, so I’ll probably never work up the courage to actually explore it. Hopefully, our automated friends will do the work for us and help us understand what is still a very much unexplored frontier of Earth.

The paper “Constraint on net primary productivity of the global ocean by Argo oxygen measurements” has been published in the journal Nature.

UK researchers map “profound long‐term changes” in plankton populations around their island

Plankton living in the waters around the UK have been undergoing dramatic changes in the past six decades, a new study reports.

In this image, triangles represent coastal stations while grid squares illustrate trends in Continuous Plankton Recorder data — blue indicates a decreasing abundance trend, while orange indicates an increase.
Image credits: University of Plymouth

The findings showcase the effect of climate change on the microscopic algae, which underpin the entire ocean food web. The results are particularly worrying as changes in plankton populations can have drastic ramifications for the health of all ocean life and the services they provide to humanity around the globe.

A sea of troubles

“Plankton are the base of the entire marine food web. But our work is showing that climate change has caused plankton around UK waters to experience a significant reorganisation,” says Dr. McQuatters-Gollop, the lead scientist for pelagic habitats policy for the UK and co-lead author of the study.

“These changes in the plankton suggest alterations to the entire marine ecosystem and have consequences for marine biodiversity, climate change (carbon cycling) and food webs including commercial fisheries.”

The study, led by members from the University of Plymouth, collaborated with researchers across the UK and combined findings from several offshore surveys such as the Continuous Plankton Recorder (CPR) and UK inshore long-term time-series. Then, the team overlapped these observations with records of sea surface temperature changes to see whether climate change was impacting plankton communities — they found that yes, it has been, for at least six decades.

The analyses of plankton functional groups showed profound long-term changes across large geographical areas around the UK coastline. For example, the average abundance of meroplankton (a group of animal plankton which includes lobsters and crabs that lives on the seafloor) between 1998 and 2017 was 2.3 times higher than the average for 1958-1967 in the North Sea, coinciding with a period of increasing sea surface temperatures. At the same time, a general decrease in plankton species that live in the water column and a decrease of up to 75% in offshore species populations could be observed.

The team explains that their results provide further evidence that human activity is placing both direct and indirect pressure on marine ecosystems, which are buckling under the strain. They further note that it is vital for us to understand the effect we’re having on these ecosystems since any perturbation here will be felt throughout our communities as well. Commercial fish stocks, sea bird populations, and the ocean’s ability to create oxygen from CO2 are all dependent on plankton.

“In this paper, we have tried to turn decades of speculation into evidence. It has long been thought that warming seas impact on plankton, the most important organisms in the marine food web,” says Professor Paul Tett, from the Scottish Association for Marine Science (SAMS) in Oban, co-author of the paper.

“By bringing together such a large, long-term dataset from around the UK for the first time, we have discovered that the picture is a complex one. We therefore need to build on the success of this collaboration by further supporting the Continuous Plankton Recorder and the inshore plankton observatories.”

The paper “Lifeform indicators reveal large‐scale shifts in plankton across the North‐West European shelf” has been published in the journal Global Change Biology.

Ocean.

Climate change may make the oceans belch out CO2, study warns

As oceans warm up due to climate change, they’ll likely start generating a lot of CO2.

Ocean.

Image via Pixabay.

Despite being the largest carbon sink active today, oceans might become net emitters under warmer climates, a new study reports. The paper reports that warmer oceans lose some of their ability to store carbon, which will accelerate the rate of CO2 regeneration in many areas of the world. This will further reduce the ocean’s ability to store carbon, the authors explain.

Positive carbon loop

“The results are telling us that warming will cause faster recycling of carbon in many areas, and that means less carbon will reach the deep ocean and get stored there,” said study coauthor Robert Anderson, an oceanographer at Columbia University’s Lamont-Doherty Earth Observatory.

Ocean water soaks up roughly 25% of our carbon dioxide emissions year after year. While this process also involves abiotic chemical and physical processes, the lion’s share of that CO2 is gobbled up by plankton through photosynthesis. But, all plankton must die eventually, and when they do, these tiny marine plants sink to the bottom of the ocean — and the carbon they ‘ate’ goes down with them. It’s estimated that plankton produces around 40 to 50 billion tons of dry, solid organic carbon each year.

Some of this organic matter (and the carbon therein) gets locked into the depths for centuries at a time, but part of it gets consumed by aerobic bacteria before sinking into oxygen-free waters, the team writes. Those bacteria then expel it as carbon dioxide, pushing it back into the atmosphere. Only about 15% of plankton-derived carbon sinks to the bottom of the sea, the authors estimate. They further report that the environmental conditions that allow bacteria to recycle carbon are spreading as water temperatures rise.

The team used data from a 2013 research cruise from Peru to Tahiti. They focused on two distinct regions: nutrient-rich, highly productive waters off South America, and the largely infertile bodies of water that form the South Pacific Gyre. Instead of using traditional sampling methods — simple devices that trap particles as they sink — the team pumped large amounts of water from different depths and isolated particles and thorium isotopes. This approach allowed them to calculate the quantity of carbon sinking at different depth intervals, they explain, and much more reliably so — the technique yielded far more data than the traditional traps.

Deeply worrying

In the oxygenated upper waters layers off South America, the team reports, oxygen gets used up very quickly. It is consumed completely at about 150 meters of depth, halting aerobic activity. Organic matter that reaches this layer (called the oxygen minimum zone, OMZ) will sink to the bottom of the ocean. In the depths, oxygen levels do increase again, and aerobic bacteria start breaking down organic matter. However, any CO2 produced down that far will take centuries to get back into the air via upwelling currents.

The OMZ thus forms a sort of protective cap over any organic matter that sinks past it, according to the team. The common wisdom of today, held that organic matter produced near the surface makes it through the OMZ, and that most CO2 regeneration takes place in the deep ocean. However, only about 15% of this matter sinks past the OMZ, the team shows.

“People did not think that much regeneration was taking place in the shallower zone,” said the study’s lead author, Frank Pavia, a graduate student at Lamont-Doherty. “The fact that it’s happening at all shows that the model totally doesn’t work in the way we thought it did.”

As mean water temperatures in the ocean increase, OMZs will spread both horizontally and vertically, covering larger areas of ocean at shallower depths, the team estimates. At the same time, higher temperatures will drive bacterial activity above the OMZs. On one hand, this would allow more organic matter to sink undegraded into the deep. However, the increased rate of CO2 regeneration near the surface will counteract this increased trapping, the team says. Whether near surface regeneration or the cap provided by the OMZ might have a stronger effect is still something we need to look into, they explain. However, this shift in OMZs is definitely not good news, as they are not at all suitable for most marine life — and this shift will affect a lot of today’s key fishing areas.

In the South Pacific Gyre, the results were less ambiguous. There is far more regeneration near the warmer surface than previously estimated in this area. The South Pacific Gyre and similar current systems in other parts of the oceans are projected to grow as the oceans warm. The gyres will divide waters into warmer layers (on the surface) and colder ones (deeper down). Because much of the CO2 regeneration will take place in the warm, shallower waters, CO2 regeneration will pick up over wide spans of ocean, the team explains. And, unlike below the nearer-shore OMZs, “there is no counterbalancing effect in the gyres,” said Anderson.

“The story with the gyres is that over wide areas of the ocean, carbon storage is going to get less efficient.” (There are four other major gyres: the north Pacific, the south and north Atlantic, and the Indian Ocean.)

These are only parts of the ocean carbon cycle, the team notes. Abiotic reactions are responsible for significant exchanges of carbon between atmosphere and oceans, and these processes could interact with the biology in complex and unpredictable ways.

“This [the study] gives us information that we didn’t have before, that we can plug into future models to make better estimates,” said the study’s lead author, Frank Pavia, a graduate student at Lamont-Doherty.

The paper “Shallow particulate organic carbon regeneration in the South Pacific Ocean,” has been published in the journal PNAS.

Wave.

Climate change will recolor much of the oceans by 2100, MIT research suggests

Climate change might be changing the oceans’ color in the future, new research reveals.

Wave.

Image credits Dimitris Vetsikas.

Significant changes to global phytoplankton populations and their distributions in the coming decades will intensify the oceans’ blues and greens, new research from MIT suggests. These changes should be observable from orbit, the authors add, meaning satellites could be used as an early warning system against wide-scale changes in marine ecosystems.

Blue-green algae

The team reports developing a global model which simulates the growth rate and interactions between different species of phytoplankton (bacteria and single-cell algae). This model allowed them to estimate how the mix of phytoplankton species will evolve in various locations throughout the world as temperatures rise in the future.

The team also simulated how phytoplankton absorb and reflect light, and estimates a perceivable change in the ocean’s color as global warming affects the makeup of phytoplankton communities.

“The model suggests the changes won’t appear huge to the naked eye, and the ocean will still look like it has blue regions in the subtropics and greener regions near the equator and poles,” says lead author Stephanie Dutkiewicz, a principal research scientist at MIT’s Department of Earth, Atmospheric, and Planetary Sciences and the Joint Program on the Science and Policy of Global Change.

“That basic pattern will still be there. But it’ll be enough different that it will affect the rest of the food web that phytoplankton supports.”

Falkland Islands phytoplankton bloom.

An example of how phytoplankton can change ocean color. Picture taken off the coast of the Falkland Islands, 2015.
Image credits NASA via Wikimedia.

The team allowed their model to simulate conditions up to the end of the present century. By the year 2100, they report, over 50% of the world’s oceans will suffer shifts in color due to climate change. Areas that are predominantly blue, such as the subtropics, will become even more blue as phytoplankton — and all the life it supports, which is virtually all life in the area — dwindle. Greener areas, such as those near the poles today, may turn deeper shades of green as warmer temperatures cause blooms of phytoplankton.

Ocean color is formed by the interaction between light, water, and whatever is in the water. H2O itself absorbs most of the light spectrum except for part of the blue wavelengths — which get reflected. That’s why relatively-pure oceans or other bodies of water look blue from space. Organisms in the water tend to change this overall color, as they absorb and reflect different wavelenghts of light.

Based on this principle, scientists have been using satellites to measure ocean color since the late 1990s. This data can be used to estimate the amount of chlorophyll in a given ocean region, and by extension the amount of phytoplankton. But Dutkiewicz says chlorophyll estimates don’t necessarily reflect climate change — significant swings in chlorophyll could come down to global warming, but they could also be due to “natural variability” due to natural phenomena such as weather.

“An El Niño or La Niña event will throw up a very large change in chlorophyll because it’s changing the amount of nutrients that are coming into the system,” Dutkiewicz says. “Because of these big, natural changes that happen every few years, it’s hard to see if things are changing due to climate change, if you’re just looking at chlorophyll.”

Phytoplankton bloom swirly.

A particularly-swirly Phytoplankton bloom off the coast of South Africa, near where the South Atlantic meets the Southern Indian Ocean.
Image credits Flickr / NASA Goddard Space Flight Center.

So the team looked to satellite measurements of reflected light, instead. They started with a computer model used previously to predict phytoplankton changes caused by rising temperatures and ocean acidification. This model takes information about phytoplankton, such as feeding and growth patterns, and incorporates it into a physical model that simulates the ocean’s currents and mixing. However, this time they also gave the model the ability to estimate the specific wavelengths of light absorbed and reflected by the ocean, depending on the amount and type of organisms in a given region.

“Sunlight will come into the ocean, and anything that’s in the ocean will absorb it, like chlorophyll,” Dutkiewicz says. “Other things will absorb or scatter it, like something with a hard shell. So it’s a complicated process, how light is reflected back out of the ocean to give it its color.”

The model’s results were compared to actual measurements of ocean-reflected light taken in the past. The two data sets matched well enough to suggest the model can be used as an accurate predictor of ocean color in the future, the authors write.

So the team allowed the model to work after setting mean temperatures to rise by up to 3 degrees Celsius up to 2100. This increase is consistent with most estimates of how climate conditions will fluctuate under a business-as-usual scenario. Blue and green wavelengths responded the fastest under this scenario, the researchers report. They add that these wavelengths also show a significant shift, due specifically to climate change, much earlier than previously predicted climate-change-induced changes in chlorophyll by 2055.

“Chlorophyll is changing, but you can’t really see it because of its incredible natural variability,” Dutkiewicz says. “But you can see a significant, climate-related shift in some of these wavebands, in the signal being sent out to the satellites. So that’s where we should be looking in satellite measurements, for a real signal of change.”

According to their model, climate change is already changing the makeup of phytoplankton, and by extension, the color of the oceans. By the end of the century, they add, we will see “a noticeable difference in the color of 50 percent of the ocean”, with “potentially quite serious” implications. Different hues of chlorophyll absorb different wavelenghts of light, and such climate-induced changes could have a dramatic impact on the ocean’s food webs, the team concludes.

The paper “Ocean colour signature of climate change” has been published in the journal Nature Communications.

Light pollution from research ship makes Artic zooplankton return to the deep

Zooplankton.
Image credits: Wikipedia.

Scientists discovered that zooplankton from the Arctic is very sensitive to light pollution. Even light coming from research ships can make these small organisms sink back into darkness. Sure, it was previously known that the light of a full moon or the northern lights would make these creatures retreat to deeper waters, but the possibility that ship-borne lights bothered them was still debatable.

“We did have a suspicion that this was the case,” said Martin Ludvigsen, a professor in NTNU’s Department of Marine Technology and at the university’s Centre of Autonomous Marine Operations and Systems. “We were able to demonstrate this, and show the significance of the lights from the ship” he added.

Run for the depths!

Zooplankton is the most widespread vertical migratory biomass on Earth (and armed to the teeth). Around the globe, these tiny animals rise to the surface during the night to feed and descend into deeper waters to avoid predators during the day. Research over the last decade shows that the weak moonlight or the northern lights cause zooplankton to retreat to darker waters.

Because of its photosensitivity, scientists have a hard time actually studying zooplankton: if light from their ships shines through to the small animals, any accurate recording of their population in an area becomes highly improbable.

To better understand the effects of light and light pollution on zooplankton, a team of researchers from NTNU, UiT (The Arctic University of Norway), the University of Delaware, and the Scottish Association for Marine Science modified a kayak, equipped it with sensors, a petrol engine, strapped it to a ship, and set it all out to sea. Once in open waters the kayak, dubbed Jetyak, was sent away from the research vessel and used to measure the depth reached by artificial light, as well as to record plankton thickness via sonar.

The “Jetyak” and a part of the research team.
Photo: Geir Johnsen, NTNU/UNIS

The acoustic data collected by the autonomous Jetyak showed that the layer of zooplankton was far thicker and started from closer to the surface near itself compared to that near the research boat (where the plankton was hiding from light). This effect reached depths of up to 80 meters.

“We were sort of surprised how pronounced this avoidance behavior was,” Ludvigsen said. “It was so clear and so fast. Even when we tried to reproduce this in a small boat and a headlamp, it was really easy to see in the echosounder.”

Photo from the board of the research ship.
Photo: Benjamin Hell

“These findings tell us that zooplankton populations and behavior can be under- or overestimated because these marine organisms respond to light, either by swimming away from it, or sometimes towards it,” said Geir Johnsen, co-author and a marine biologist at NTNU.

The biologist believes that scientists have to undertake their studies under natural conditions if they want to discover what zooplankton is truly up to. This means developing autonomous vehicles equipped to sample the vast seas.

Arctic fauna — ranging from bowhead whales to marine birds, to cod — feeds on zooplankton, particularly those in the genus Calanus. Their high content of fatty acids is what makes them such a filling meal.

Calanus glacialis
Photo: Malin Daase, UiT — The Arctic University of Norway

“Light pollution may disturb zooplankton behavior with respect to feeding, predator-prey relationships and diurnal migration, in addition to their development from juveniles to adults,” Johnsen said.

Global warming also poses a serious threat to the Arctic’s tiny inhabitants — as sea ice cover is growing thinner, or outright melting completely in large areas, zooplankton is rapidly running out of the dark areas they like, Johnsen remarked. Considering how central zooplankton is on the local menus, the Arctic ecosystem may have a lot to suffer.

The paper was published in the journal Science Advances.

A nudibranch, or sea slug, feeding on hydroid colonies. Credit: Gabriella Luongo.

A lazy seaslug hunts by ‘kleptopredation’, letting prey do half the work for it

A Mediterranean sea slug is an underwater pirate. British researchers found that the animal purposely targeted well-fed hydroids — distant relatives of coral — in order to consume the prey’s prey, so to speak. According to experiments, half of the sea slug’s diet is plankton, which is what the hydroids prey on.

A nudibranch, or sea slug, feeding on hydroid colonies. Credit: Gabriella Luongo.

A nudibranch, or sea slug, feeding on hydroid colonies. Credit: Gabriella Luongo.

Trevor Willis, a marine ecologist at the University of Portsmouth, UK, calls the intriguing behavior ‘kleptopredation’. The cunning and brutal feeding strategy belongs to Cratena peregrina, nudibranch species belonging to the sea slug family. It lives off the coast of Sicily where it likes to feed on the branched colonies of Eudendrium racemosum hydroids.

“This is very exciting, we have some great results here that rewrite the text book on the way these creatures forage and interact with their environment,” Willis said.

Secondhand grocery shopping

Hydroid colonies consist of individual polyps that feed on plankton and small crustaceans. After closely following Cratena p.‘s feeding patterns, the researchers found that the nudibranch preferred to eat polyps that had only recently fed. Specifically, the sea slug doubled its attack rate on prey that had just dined on zooplankton. The findings also explain why some biochemical signatures that distinguish predators from prey don’t work out clearly for nudibranchs and hydroids.

Willis says that, effectively, the colorful sea slug is using another species as a fishing rod so it can easily gain access to food it otherwise wouldn’t have. What’s more, the sea slug’s prey does all the work for it.

“People may have heard of kleptoparasitic behaviour – when one species takes food killed by another, like a pack of hyenas driving a lion from its kill for example. This is something else, where the predator consumes both its own prey and that which the prey has captured,” Willis explained.

The researchers first realized that they were dealing with a novel predation pattern after they looked at nitrogen isotope levels in the nudibranchs, hydroid polyps, and zooplankton, discovering that the sea slugs had much lower levels than expected if polyps were their only prey. This investigation suggested that the hydroid polyp represent a fraction of the total mass ingested by the sea slugs.

Oddly, this behavior might actually benefit the hydroid colony in the long-run. By increasing its energy intake from their prey’s plankton diet, the sea slugs effectively consume fewer polyps than they would have otherwise. As such, the nudibranch’s novel predation extends the life of the hydroid colony.

It’s not clear at this point how widespread the behavior is. This is something which Willis and colleagues are investigating.

“Our ability to understand and predict ecosystems in the face of environmental change is impeded by a lack of understanding of trophic linkages,” said Dr Willis, but he added there was still a lot to learn from research. “While we have some great results, like any science worth its salt, it raises more questions than it answers.”

Scientific reference: Kleptopredation: a mechanism to facilitate planktivory in a benthic mollusc, Biology Letters (2017).

Phytoplankton paints Bosphorus Strait in a stunning milky turquoise

An unexpected  “phytoplankton bloom”  has turned the normally dark blue waters of one of the busiest shipping routes in the world into a stunning turquoise. Istanbul residents were delighted with the bright and milky water, as they were quick to point out on social media.

The Bosphorus is the narrowest strait used for international navigation and separates continental Europe from Asia. NASA has been monitoring the sudden change in color of the water around straight and says phytoplankton is responsible.

Phytoplankton are microscopic marine algae that form the basis of most marine food webs. In a balanced ecosystem, they provide food for a wide range of sea creatures including whales, shrimp, snails, and jellyfish. These tiny organisms feed on sunlight and dissolved nutrients, all of which are in ample amount in the Bosphorus from rivers like the Danube and Dnieper.

An amazing shot taken by NASA's Aqua satellite shows an algae bloom in full swing around the Black Sea. Credit: Ocean Biology Processing Group/NASA.

An amazing shot taken by NASA’s Aqua satellite shows an algae bloom in full swing around the Black Sea. Credit: Ocean Biology Processing Group/NASA.

One of the most common types of phytoplankton around the Black Sea are coccolithophores, which are distinguishable by being plated with calcium carbonate — the stuff shells are made of. When they aggregate in large numbers, the phytoplankton acts like a reflective plate lending a milky appearance to the water that can be visible even from space.

“The May ramp-up in reflectivity in the Black Sea, with peak brightness in June, seems consistent with results from other years,” said Norman Kuring, an ocean scientist at NASA’s Goddard Space Flight Center.

Sometimes, plankton can make the water darker.

“It’s important to remember that not all phytoplankton blooms make the water brighter,” Kuring said. “Diatoms, which also bloom in the Black Sea, tend to darken water more than they brighten it.”

The coccolithophore in question is Emiliania huxleyiaccording to Berat Haznedaroglu, an environmental engineer, who claims rain events that carried nutrients from the Saharan desert to the Black Sea have created the optimal environment for the phytoplankton bloom. Such events happen annually, much to the delight of locals.

Blue Whale.

Ancient climate change turned whales into Earth’s largest organisms ever , study reports

Ancient shifts in climate may have powered the baleen whale’s growth to such “ginormous” sizes, a new paper reports.

Blue Whale.

“Ginormous” seems rather fitting.

With some individuals growing to be the length of an average basketball court and weighing upwards of 200,000 kilograms (441,000 pounds), the blue whale is big fry indeed — in fact, they’re believed to be one of the largest animals that have ever lived on Earth. Which naturally begs the question of what led them, and their kin, to grow to such proportions.

[Turns out that a long time ago, a larger-than-whales dinosaur roamed the Earth. Why not read about it?]

Up to now, biologists have had (and debated over) two main theories in regards to why. The first one is that whales simply grew because they could, as water provides a lot of buoyancy for their bodies. So although they’d weigh a lot on dry land, way too much to be able to even move, they’re pretty nippy underwater and can still catch prey quite easily. The other theory is that the whales grew out of necessity, as their monumental size made them virtually immune to the attacks of giant sharks or other mega-predators.

Another point of interest is when they got so large. One paper published in 2010 under the lead of Graham Slater, an evolutionary biologist currently at the University of Chicago in Illinois, estimates that cetaceans (the whale’s extended family) split into size groups around 30 million years ago. It’s a lineage that still holds today, the paper argues — so the baleen whales trace their ancestry to the giant group, predatory whales (such as the beaked whale) hail from the middle-sized group, and dolphins from the runts of the litter, becoming the smallest of cetaceans.

Chubby cheeks

A new paper however could address both questions in one single swoop. Penned by Slater alongside Nicholas Pyenson, a whale expert at the Smithsonian Institution’s National Museum of Natural History in Washington D.C., and Jeremy Goldbogen at Stanford University in Palo Alto, California, the paper proposes that the whales’ size is a product of environmental stresses associated with global cooling in the Neogene some 4,5 million years ago.

The paper started taking shape a few years ago when Pyenson and Slater started working with the museum’s cetacean fossil collection to see if the diverging lineages theory holds water. Previously, Pyenson studied living whale populations to determine that a whale’s total size correlated well with the width of its cheekbones. So the duo gathered this numbers for 63 extinct whale species and 13 contemporary ones and plotted these values over the family’s timeline.

The trend showed that there weren’t any big whales early on, contradicting Slater’s earlier theory. There wasn’t any gradual increase in size over time, either — instead, what the team saw was that whales became moderately large and stayed so up until about 4.5 million years ago. After this, baleen whales suddenly grew “from relatively big to ginormous,” Slater says.

In case you’re not familiar with the ginormity scale, whales 4.5 million years ago clocked in at around 10 meters (about 32.5 feet) long — whereas today’s blue whales grow to around 30 meters (98.5 feet). So evolutionary speaking, the whales’ size is a pretty recent development.

Long road, big fins

Whale Fins.

“Laters haters!”

The next step was to look at the going-ons of the time to see what caused this very dramatic, 300% increase in size. The team found that the growth coincided with the beginning of the first ice ages. They explain that the colder climate lead to an increase in glacier cover which would melt during the warmer months of spring and summer, sending cold sediment (and nutrient) rich runoff into coastal waters which supported plankton and zooplankton (who like cold waters) blooms — which the whales were more than happy to dine on.

The problem was that until then, this krill was evenly distributed in the oceans and relatively plentiful, so the whales could go anywhere they pleased and dinner would be waiting for them. But climate change killed off most of the ocean biosphere at the time (ironic isn’t it) and severely weakened existing ecosystems, drastically lowering primary and secondary productivity (the rate at which plants turn sunlight into organic compounds, and the rate at which animals turn plant matter into their own biomass respectively).

Combined, this changed the pattern of food availability from “decent food pretty much anywhere” to “truckloads of food in far-apart areas at certain times during the year,” and the whales had to adapt. Goldbogen, who studies whale eating and diving behavior, helped explain the link between food availability and size. The more concentrated food becomes, larger whales with really big mouths gain a huge boost to feeding efficiency, he says. Moreover, larger whales could travel between feeding areas faster and with less effort than smaller ones.

Overall, these two factors put huge selective pressures on growing larger frames, so the bigger species thrived while smaller whales went extinct.

The paper, while not being the first to show how food and feeding habits shaped whale evolution, does offer a simple and pretty elegant explanation for the whales’ size. It also goes to show that evolution is powered by an interplay of factors, from climate to the way other species adapt to present conditions. And finally, it shows that a species’ adaptation to one particular constraint — in the whales’ case, food availability — can inadvertently address some of its other needs — such as safety from predators — or provide an unexpected boon to ecosystems.

The full paper “Independent evolution of baleen whale gigantism linked to Plio-Pleistocene ocean dynamics” has been published in the journal Proceedings of the Royal Society B.

Zooplankton are armed to the teeth with spears and ballistic weapons, electron photography shows

Plankton might be a whole lot more ‘Grayjoy’ than ‘Tyrell’. A recent paper shows that these seemingly innocent bits of life are armed to the teeth with stabbing appendages and even ballistic weapons.

P. kofoldii.

SEM image of P. kofoldii. White arrow points to its taenlocyst.
All image credits Gavelis et al., (2017), Science Advances.

Hack, whack, pew-pew

An international team of researchers has captured the crispest images to date of the arsenals microbes employ to hack away at their fellows — and it’s seriously impressive, if a bit small. The tiny combatants pack spears, wicked harpoons, and even something that looks suspiciously similar to a bug-sized 15-barreled Gatling gun.

To get a better idea of what kind of heat these microscopical hordes are packing, PhD student Gregory S. Gavelis from the University of British Columbia, Vancouver, Canada and his team used a focused ion beam scanning electron microscope to snap 2D images which they then put together in 3D reconstructions.

The team started with single-cell dinoflagellate Polykrikos kofoidii, known to hunt plankton using a harpoon-like weapon. Their work showed that P. kofoidii uses a double step attack to capture and drag prey in. First, a taeniocyst (which is similar to a dart) is shot towards the prey, After making contact, it sticks to the hapless victim and injects a store of liquid through its membrane — the team doesn’t yet know what it is, but they suspect it’s a kind of venom.

Taenlocyst.

(B) discharged taenlocyst, (C) nematocyst.

A discharged nematocyst, a discharged nematocyst with its tubule, and a nematocyst piercing a cell.

The second phase of the attack is the harpooning itself. A weaponized organelle called nematocyst pierces the incapacitated prey and hooks it with a stylet and then it’s dinner time.

Ok, so they have tiny spears. Uuh, so scary. Us humans nailed that down a long long time ago, probably between figuring out how to sitting down and do fillings. It’s like you’re not even trying, plankton. You’ll need something a lot more dramatic to impress us. Something like…

A really tiny minigun

Another dinoflagellate the team worked with, a wild-caught Nematodinium, shows something strikingly similar to a ballistic weapon. The cell is topped with a radial structure which crowns a nematocyst with 11 to 15 ‘barrels’. The organelle rings one side of the Nematodinium’s outer membrane, making it resemble a Gatling gun. Its internal structure is also eerily similar to what you’d expect to see in a firearm, further suggesting that its role is either to hunt down prey or fight off predators.

Nematodinium.

A 3D reconstruction of Nematodinium and its gun.

The team also performed a full genetic analysis to find out where these dinofllagelates’ total lack of chill comes from, and if there’s any chance that the related phylum cnidaria (some species of whom use similar ballistic weapons) got them from the same ancestors. After pooling genetic data from over a hundred dinoflagellates, however, the team says both groups evolved these weapons independently, even if their results are very similar.

“Despite the misconception that phytoplankton are passive cells, eukaryotic algae have given rise to (and arose from) multiple predatory lineages and, in the process, have independently evolved sophisticated ballistic organelles that exceed those of animals in complexity,” the authors conclude.

The paper “Microbial arms race: Ballistic “nematocysts” in dinoflagellates represent a new extreme in organelle complexity” was published in the journal Science Advances.

Oil seeps create thriving micro-ecosystem

Natural hydrocarbon seeps are providing the nutrients for vast microbial communities to thrive in the Gulf of Mexico. Although the oil itself is not particularly beneficial, the nutrients it brings up enable the micro-ecosystem to flourish.

Researchers from Columbia University have discovered how bubbles formed by naturally-occurring oil seeps in the Gulf of Mexico attract large volumes of microorganisms known as phytoplankton. They believe this is because of the amount of nutrients from the ocean floor that the bubbles bring with them to the surface.
(Photo : Ajit Subramaniam | Columbia University)

Petroleum seeps are quite common in many areas of the world, though many of them have already been exploited completely. In fact, oil seeps have been exploited since ancient times, by both humans and microorganisms. However, marine seeps are relatively understudied, and only in recent years have we become better at detecting them through remote sensing.

Seeps generally flow at a very slow and steady rate; the material that flows is generally toxic, but some organisms that live nearby have adapted to the conditions and even take advantage of them. This seems to be the case with phytoplankton communities gather in areas of the Gulf .

“This is the beginning of evidence that some microbes in the Gulf may be preconditioned to survive with oil, at least at lower concentrations,” oceanographer Ajit Subramaniam from Columbia’s Lamont-Doherty Earth Observatory said.

The theory is that rising oil and gas bubbles are bringing up deep-water nutrients that phytoplankton need to grow. This would explain why the biggest blooms are located above the seeps, but at a distance. The highest phytoplankton concentration was located several hundred feet below the water surface – twice higher than the average.

“In this case, we clearly see these phytoplankton are not negatively affected at low concentrations of oil, and there is an accompanying process that helps them thrive. This does not mean that exposure to oil at all concentrations for prolonged lengths of time is good for phytoplankton.”

Following a series of lab experiments, Subramaniam found that while the organisms can tolerate low quantities of oil in their environment, it does nothing good for them. In this case, it remains to be seen what the long-term impact will be on the plankton.

“The direct effect of oil is usually negative, but in some cases small amounts of oil can be outweighed by the positive effect of the nutrients that are tagging along,” added Andy Juhl, an aquatic ecologist at Lamont and coauthor.

For now, researchers are trying to obtain a broader view of the seeps in the Gulf and how they affect microbial activity. They don’t know what types of plankton thrive under these conditions and what (if any) damage long-term exposure does. This ecosystem consisting both of plankton and oil-degrading bacteria and other microbes is likely very complex and it’s not clear how this influx of nutrients affects its internal balance.

“Satellite radar data have given us a detailed picture of where natural seeps are concentrated across deep seafloor of the Gulf of Mexico,” said co-author Ian MacDonald, an oceanographer and professor at Florida State University. “Building on this, the present, novel results show biological effects near the ocean surface in areas where seeps are most prolific.”

Journal Reference: Elevated surface chlorophyll associated with natural oil seeps in the Gulf of Mexico.

A malformed (’teratological’) chitinozoan specimen of the genus Ancyrochitina (a) and a morphologically normal specimen (b) of the same genus. Image: Dr Thijs Vandenbroucke

Malformed plankton is a telltale sign of mass extinction

Mass extinctions present both a mortal threat and opportunity. During these events, a great deal of all terrestrial and marine life perishes, but this also makes room for the next lineage to flourish in its stead. Like a bush fire, mass extinctions may be nature’s way of “cleansing” – a reboot for new experimentation to start fresh. Despite being extremely important (it doesn’t get more dramatic than “mass extinction”), the kill triggers that spur these events in motion are still poorly understood.  But we’re learning. For instance, a team reports that ancient malformed plankton are a proxy for mass extinction events.

Life morphed by heavy metals

Thijs Vandenbroucke, a researcher at the French CNRS and invited professor at University of Gent, Belgium, led the team which investigated the fossils. He and colleagues found that the malformed plankton from the Ordovician and Silurian periods (ca. 485 to 420 to million years ago) had high concentrations of lead, iron and arsenic.

It’s well established that these heavy metals cause morphological deformities in modern organisms. The assumption is that the same holds true for these ancient organisms as well.

A malformed (’teratological’) chitinozoan specimen of the genus Ancyrochitina (a) and a morphologically normal specimen (b) of the same genus. Image: Dr Thijs Vandenbroucke

A malformed (’teratological’) chitinozoan specimen of the genus Ancyrochitina (a) and a morphologically normal specimen (b) of the same genus. Image: Dr Thijs Vandenbroucke

Based on these findings, Vandenbroucke suggests that the spread of oxygen depletion and toxic metals are the likely cause of aquatic mass extinction events, rather than glacial episodes as previously suggested. The two are closely intertwined as reduction in ocean oxygenation drives a subsequent increase of these metals. “In normal, oxic conditions, such metals precipitate and remain sequestered in marine sediments,” Vandenbroucke told me in an e-mail.

“We think these are significant factors during the event we studied. In addition, we also observe strikingly similar patterns (i.e. coinciding carbon-isotope excursions, increased malformation, and extinction events) for many of the other Ordovician-Silurian events, including during the Hirnantian, a major mass extinction that eradicated up to 85% of marine species. This suggests that anoxia and metal enrichment may be a contributor to all of these events. Based on the new insights gleaned from the pilot study we now published, we are currently investigating several of these events, in order to test our hypotheses,” Vandenbroucke said.

The high levels of metals suggest changes in the ocean chemistry and the spreading anoxia may have been a contributing kill-mechanism during these early extinction events. This would make any fossilized malformed plankton extremely useful as a forensic tool – a  biological indicator of periods of low oxygen levels. Findings modern day malformed plankton would also be a cause of alarm, one that should be duly noted – and that’s an understatement.

Charles Lyell, a towering figure in the early development of the geologic sciences, suggested that “the present is the key to the past.” Flipping Lyell’s axiom to “the past is key to understanding our future” should always be done with caution – in particular when comparing the modern environment with something as old and different as the Ordovician-Silurian world. The megafauna extinctions of today are not a consequence of marine events but many parts of the marine food web are directly affected by the processes we describe. Our study, for example, might help highlight processes and hidden consequences, caused by fluxes of anthropogenic elements to the world’s oceans, that need to be considered when studying the ever-increasing problem of marine eutrophication and anoxia in some coastal areas,” Vandenbroucke said.

Distribution of potential oceanic anoxic events (OAEs) in the uppermost Ordovician and Silurian. Credit: Thijs Vandenbroucke et. al. Nature Communications

Distribution of potential oceanic anoxic events (OAEs) in the uppermost Ordovician and Silurian. Credit: Thijs Vandenbroucke et. al. Nature Communications

 

Global warming has never looked so beautiful: Glowing plankton in Tasmania

Tasmania’s Derwent River has put on a garb of surreal blue these past few nights as blooms of bioluminescent plankton light up the dark waters. But while photographers scramble to catch breathtaking pictures, scientists point to the more dire implications of the invasion of these tiny organisms so far south.

Someone spilled their mana potion.
Credit: Jonathan Esling

Noctiluca scintillans, also known as Sea Sparkles, is a type of phytoplankton (meaning tiny plants rather than zooplankton, the small animals that whales dine on), particular in that it feeds on other plankton.

“As creatures go, it’s more of the unwanted kind. In extreme cases it can cause fish kills; it does it all over the world,” says Lisa Gershwin, author of Stung! On Jellyfish Blooms and the Future of the Ocean.

However, it wasn’t until 1994 that these tiny dinoflagellates were spotted this far to the south, and by 2004 sightings started to become much more common.“The displays are a sign of climate change,” Anthony Richardson, from the CSIRO, told New Scientist earlier this week.

Rising temperatures strengthen the East Australian current driving warmer bodies of water towards Tasmania, raising the average temperature, making it “warm enough for Noctiluca to survive,” Richardson says.

Peter Thompson, senior principal research scientist for CSIRO Oceans & Atmosphere, based in Tasmania, confirmed that “It does represent a large change to our ecosystem. Previously it was rare or absent yet now it is the most abundant organism in the river that eats phytoplankton” for Business Insider.  in mari

Walter White’s pet plankton?
Image via mashable.com

The strain that the little plants put on the local wildlife could have devastating effects on Tasmania’s economy, which draws nearly US$ 700 million from the production of seafood each year – more than any other Australian state.

“When the [Noctiluca scintillans] cell breaks down, ammonia is released and the massive bloom could become a deadly cloud,” Gershwin said. “It can change the flavour of the water and it’s noxious to fish.”

In the open ocean this would not be a problem but in the confined water of Derwent River the build-up of ammonia could leave it uninhabitable for marine life, as fish farmers found out when Noctiluca started creeping into the local salmon farms.

That saw fish refusing to surface to feed and was eventually resolved by generating an air bubbling system with air bubbles coming up in the centre of the fish pens to clear the surface waters. Most Tasmanian fish farms have now such systems in place.

“If a dense patch gets caught in a fish pen then the ammonium can cause problems for the fish,” Thompson said. “There have been fish kills associated with these sorts of blooms in the past.”

But, he added, so far researchers have “relatively little understanding of how this has affected other aspects of the ecology of the Derwent”.

 

 

deepwater-horizon-phytoplankton_51856_600x450

Ocean trek reveals the massive diversity of the oceanic plankton [with photos]

Image: Christian Sardet/CNRS/Tara Expeditions

In one of the most amazing marine science studies I’ve seen in a while,, a team of researchers scoured the world’s oceans fishing for microbes, viruses and other tiny life during a three and a half year trip aboard a schooner. The trip was long and arduous for sure, but ultimately it paid out – big time! They collected  35,000 samples at 210 stations over the voyage, and found 35,000 species of bacteria, 5,000 new viruses and 150,000 single-celled plants and creatures.

Most of these are new to science. Only a small fraction of the newly discovered and known species alike had been genetically sequenced, but results so far show just how interconnected and symbiotic marine life is. It also means it’s also vulnerable in the face of environmental changes, particularly climate change.

Ocean’s hidden plankton

Tiny organisms that live in the ocean like viruses, bacteria and protozoa (unicellular eukaryotic organisms) are collectively called plankton. These make up to 90% of all the mass of marine life and produce 50% of all the oxygen in the world by photosynthesis. They’re also at the very bottom of the food chain, being gobbled by small fish like the goldband fusiliers and large aquatic animals like whales. As such, the whole food web is dependent on plankton. Every marine biologist is aware just how important plankton is to ecosystem. What was missing was information on its diversity.

Beautiful tiny crustacean found among one of the samples taken by the the Tara expedition.

Beautiful tiny crustacean found among one of the samples taken by the the Tara expedition.

Between 2004 and 2007,  the Global Ocean Sampling Expedition was launched with the goal of assessing the genetic diversity in marine microbial communities and to understand their role in nature’s fundamental processes. The project was funded by Craig Venter, a visionary pioneer who was one of the first to sequence the human genome. Venter, an accomplished entrepreneur, is also involved in a number of cutting-edge projects like fitting a genome sequencer on the next rover planned to land on Mars or synthesizing artificial bacteria. He’s a real badass, for sure. But while his ocean sampling expedition focused on collecting and studying marine bacteria, the Tara Oceans team went for a much bigger slice of the pie: plankton.

The team sailed more than 35,000 kilometers aboard the 36-metre Tara and collected 35,000 samples, from as close as the very top layers of water to 2,000 deep, where strange and bizarre light-depraved beings lie. Only 579 where analyzed so far, but the results presented in five papers published in Nature (1,2,3,4,5) are already heralded as milestones. Before Tara, biologists knew of 11,000 different species of plankton. There’s now evidence they found 10 times more. Of the 5,000 virus communities only 39 had been described by science before. And we might be only scratching the surface. Plankton is truly as diverse as it is big, collectively.

40 million previously undescribed genes and a raft of related sample data from the Tara Oceans expedition is freely available through EMBL-EBI.
Image: EMBL-EBI/Tara Expeditions

“The whole project provides a really valuable database to enable us to interrogate the microbial ecosystems of our oceans in an unprecedented way,” says Jack Gilbert, a microbial ecologist at the Argonne National Laboratory in Illinois.

The real breakthrough was reported in the genetic analyses. Some 40 million genes were described, 80% unknown before. Then, they used this information to simulate how plankton communities interact. For instance, their models showed that based on their genetic makeup a flatworm belonging to the genus Symsagittifera would have a symbiotic interaction with a photosynthetic microalga of the genus Tetraselmis. To check, they collected worm specimens, put them under the microscope and found algal cells inside the worms and matched the DNA label of these algae to the ones predicted to be symbionts. This, along with other examples, makes it highly likely that their predictions on a wider scope – for the thousands of species – might also be on par.

Fish larvae and jellyfish are also planktonic organisms.

Fish larvae and jellyfish are also planktonic organisms.

Most importantly, the analyses showed that plankton, particularly bacteria, are vulnerable to temperatures shift. More so than changes in salinity or oxygen. This means global warming might be putting plankton, and consequently all marine life, at a greater risk than previously thought.

“It is temperature that determines what sort of communities of organisms we find. If we look at our data and we see what organisms are there, we can predict with 97% probability the temperature of the water they are living in,” said Dr Chris Bowler, from the National Centre for Scientific Research (CNRS), in Paris.

“These organisms are most sensitive to temperature, more than anything else, and with changing temperatures as a result of climate change we are likely to see changes in this community.”

Dr Bowler continued, speaking for the BBC: “The amount of data we have released is already enormous; it is one of the largest databases of DNA available to the scientific community. But we’ve analysed perhaps 2% of the samples we have collected throughout the world – so there is a huge amount of work to do in the future to understand even more about the functioning of these marine ecosystems and the importance of that for the wellbeing of the planet.
“So it’s really just the beginning of the study.”

Here are some of the most spectacular photos from the expedition:

A molluscan pteropod on the right, and 2 crustacean copepods. On the left is a fragment of orange paint from Tara’s hull. Image: Christian Sardet/CNRS/Tara Expeditions

A Sapphirina copepod collected in the Mediterranean sea. Image: Christian Sardet/CNRS/Tara Expeditions

A close relative of Turritopsis, the immortal jellyfish. Image: Christian Sardet/CNRS/Tara Expeditions

From left to right: a tiny crustacean copepod, a spider crab larva, an amphipod, a baby squid, a Phronima amphipod, and an Atlanta pteropod mollusc. Image: Christian Sardet/CNRS/Tara Expeditions

A hyperiid amphipod of the Phronima genus. Image: A.Amiel/Kahikai/Tara Oceans

This Lauderia annulata, collected and photographed on board Tara in the Indian Ocean. Image: A.Amiel/Kahikai/Tara Oceans

 

sea monkey

Sea monkeys demonstrate that tiny marine animals can move the World’s Oceans

sea monkey

Photo: flickriver.com

One could argue that a sea monkey, a pet favorite for children, isn’t the most influential creature in the animal kingdom, but you might change your opinion when you see how these organisms, along with other plankton, live as a collective. There’s only so much a human can do, but look at humanity as a whole – it completely transformed the world! Sea monkeys might be no different in some respects. After studying the tiny creatures, researchers at California Institute of Technology conclude sea monkeys create tiny, swirling currents as they migrate up and down the water column over the course of the day. When this migration pattern is joined by other  zooplankton, the generated eddy can be so powerful that they might potentially influence ocean currents globally. This also means they influence climate (currents have a direct effect on temperature), as well as the marine ecosystem (the currents spread nutrients across the ocean).

Currents on par with wind and tide: are zooplankton a force of the ocean?

Plankton encompass a diverse range of animals, from microorganisms (bacteria) to larger organisms like jellyfish, that live in the water column and can’t swim against a current. It seems, however, that plankton aren’t that passive after all. Many of these are capable of swimming up and down in dense layers throughout the day and their collective movement might be enough to mix seawater, according to biologists at Caltech.

[AMAZING] Sea plankton discovered outside International Space Station

In 2009, John Dabiri, an engineer studying biological physics at Caltech, found that jellyfish can move water over distances greater than their body length. Dabiri and colleagues are now trying to extend this work to see whether other vertical swimming animals like krill and copepods can also do this. The krill is very difficult to study in the lab, however, so they decided to study the next best thing: sea monkeys. While sea monkeys aren’t part of the vertically migrating layers in the ocean, their swimming motion is very similar to the krill. Best of all, they’re highly attracted to light which makes experiments feasible.

Sea monkeys, or brine shrimp, are nocturnal so when the sun goes down the animals swim towards the surface, while at sunset they prefer to linger in deeper waters. The researchers used a laser light to coax brine shrimp confined in a large tank to swim vertically towards the surface. Blue lasers along the side of the tank tricked the shrimp into swimming upwards, while a green laser at the top kept them there.

The water in the tank was filled with silver-coated, hollow glass spheres which allowed the researchers to visualize the generated currents. The jet of water the animals produced behind them as they swam was moving faster than the surrounding water, creating swirls and eddies known as Kelvin-Helmholtz instabilities in process. These swirls were much larger than the sea monkeys, which are only half an inch in length. Even the researchers were surprised of such an effect.

“My friends who are physical oceanographers have a healthy skepticism of [this] idea,” Dabiri says. “But you have to remember that there are billions of [plankton] in the ocean, and the whole is greater than its parts.”

Moving the climate

Most of the ocean’s biomass is comprised of plankton and taking in consideration these findings, the researchers believe that an ecosystem scale (trillions of organisms) these tiny organisms could significantly influence the ocean. In fact, the researchers estimate that one trillion watts of power are generated globally by creatures like sea monkeys and their zooplankton brethren.

[RELATED] Glow in the dark waves on the San Diego shoreline

Other experts have been quick to voice that, while the experiments were carried out correctly, the lab setting is significantly different than what happens in reality. The ocean is often stratified, with denser layers lying underneath lighter ones. This can dampen the water mixing motion observed by Dabiri and colleagues. Dabiri took notice of these comments and says he plans on replicating the experiment in an ocean setting.

“To me, an interesting aspect of this work is to see animals that seem to be at the mercy of the water play a role in shaping their own environment,” Dabiri says. “It’s something that we hadn’t appreciated, but these experiments are showing [that this] might be a common occurrence in the ocean.”

If these tiny creatures are indeed thus powerful in their collective movement (on par with tides and the wind), climate models might need to be revised to factor them in. Findings appeared in the journal Physics of Fluids.

The World’s Deepest Hole Lies Beneath this Rusty Metal Cap – The Kola Superdeep Borehole

Would you believe me if I told you that under this rusty, abandoned metal cap there lies the deepest hole ever dug by mankind? That beneath this metal seal, which measures only 9 inches in diameter, there are 12,262 meters (40,230 ft) of nothingness? You might have your doubts — but hear me out.

A journey to the center of the Earth

During the Cold War, the race for space took all the headlines, but the digging race was equally competitive (digging boreholes, that is). This is the Kola Superdeep Borehole – a project funded by the USSR and then Russia between 1970 and 1994. In that period, geologists and geophysicists had only indirect evidence as to what was going on in the Earth’s crust, and superdeep boreholes provided much-needed information for a better understanding of the underlying geology by utilizing direct observation. Even to this day, information gathered by this project is still being analyzed and interpreted.

Granites… granites everywhere

The first surprise they encountered was the lack of the so-called “basaltic layer” at about 7 km deep. Previously, the best geological information about the deeper parts of the crust came from analyzing seismic waves, and the waves suggested a discontinuity — basically, they were expecting to find granites, and as they went deeper, basalts. But much to everybody’s surprise, when they went deeper, they actually found… more granites. As it turns out, the seismic discontinuity was caused by the metamorphosis of the granites, not by basalts.

Water?!

A photograph depicting the operation of the drilling — not the best quality, but you get the picture.

As if that wasn’t enough, between 3 and 6 km deep, they also found water. By the knowledge we had back then, water simply shouldn’t have existed at those depth – and yet, there it was. Now we understand that even deep granites can get fractured, and those fractures can get filled with water. Technically speaking the water is just hydrgen and oxygem atoms squeezed out by the enormous pressures caused by the depth – and trapped in impermeable “layers” of rock.

Boiling with hydrogen

Researchers also reported the extraction of mud, which was “boiling with hydrogen” – such large quantities of hydrogen at these depths were completely unexpected.

Life — deep inside the Earth?

Without a doubt, the biggest surprise was the discovery of life: microscopic plankton fossils in rocks over two billion years old, found four miles beneath the surface. These “microfossils” represented about 24 ancient species and were encased in organic compounds which somehow survived the extreme pressures and temperatures so far beneath the Earth’s surface. This raised numerous questions about the potential survival of life forms at impressive depths.

Now, research has shown that life can exist even in oceanic crust, and even macroscopic life was found at over 1 km deep, but at the time, finding those fossils came as a shocker.

Abandoned, but not forgotten

Now, the Kola Superdeep Borehole is all but abandoned. At depths in excess of about 10,000 feet, researchers started to notice that the temperature increased faster than expected, and the first problems started to occur.  In 1983, the drill passed 12,000 m (39,000 ft), and drilling was stopped for about a year to “celebrate” the event. I have no idea why they would stop for a year to “celebrate”, but this idle period probably contributed to the breakdown in September 1984: after drilling to 12,066 m (39,587 ft), a 5,000 m (16,000 ft) section of the drill string twisted off and was left in the hole. Drilling was later restarted from 7,000 m (23,000 ft).

The drill bit used in the digging process (one of them). The nearby town of Zapolyarny holds the Kola Core Repository, which displays rock samples obtained during the drilling operation.

However, temperatures continued to grow more than the expected values, and by the time the hole reached its maximum length, the temperature was a whopping 180 °C (356 °F) instead of expected 100 °C (212 °F). The drill bit could no longer work at such temperatures, and drilling was stopped in 1992.

The entire project was closed down in 2005 due to (you’ve guessed it) of lack of funding. All the drilling and research equipment was scrapped and while data produced by the Kola drilling project continues to be analyzed, the site itself has been abandoned since 2008; the hole was welded shut by the metal cap we still see today, as if to seal off any devils or mysteries that might lurk beneath.

You can visit the now-abandoned site but, unfortunately, you won’t be able to peek through the hole that, to this day, is the deepest hole dug below the surface.

 

 

Plankton To The Rescue

plankton
Nature has a way of defending itself and even things which we fail to understand play their part. For example, the reef helps protect the shore from devastating waves and tsunamis – and the recent tragic events were in a way just a reflection of what we are doing to the planet. Massive man made constructions were no way near as effective as the reefs were.

Plankton plays a huge role in regulating our planet. They are considered to be be some of the most important organisms on Earth, due to the food supply they provide to most aquatic life. But there is something we failed to understand about them. Microscopically tiny marine organisms known as plankton increase their carbon uptake in response to increased concentrations of dissolved CO2 and thereby contribute to a dampening of the greenhouse effect on a global scale. An international group of scientists led by the Leibniz Institute of Marine Sciences in Kiel, Germany documented this biological mechanism in a natural plankton community for the first time.

Scientists  modeled the future ocean and found three major areas of concern: increased CO2 uptake by plankton will accelerate the rate of ocean acidification in deeper layers, leading to a decrease in oxygen concentrations in the deeper ocean, and will negatively influence the nutritional quality of plankton. The latter development can have consequences for entire food webs in the ocean. The world oceans are by far the largest sink of anthropogenic CO2 on our planet. Until now, they have swallowed almost half of the CO2 emitted through the burning of fossil fuels.

But we are not able to understand something about that; scientists are not sure how the oceans are able to continue to alleviate the steady rise in atmospheric CO2 in the future.

Ulf Riebesell describes the reaction of his team:

“We expected the organisms to show distinct reactions to changing CO2 conditions. What really surprised us, however, was the dimension of this effect. Basically, we can now say that the biology in the oceans is significantly affecting the global climate system.”.

He then underlined the important part of his study.

“Our results probably represent only the tip of the iceberg. I am certain that scientists will discover further biological feedback mechanisms in the near future. It is essential not only to identify and to understand these mechanisms, but also to quantify their effect on the global climate system, now and in the future. “.

This goes to show that we are just beginning to understand how what we do affects the marine life/