Acipenser sinensis NatureServe Explorer Species Reports &#8212; NatureServe Explorer is a source for authoritative conservation information on more than 50,000 plants, animals and ecological communtities of the U.S and <a href="https://www.earth.com/image/the-fall-rhapsody-in-ottawa/">Canada.</a> NatureServe Explorer provides in-depth information on rare and endangered species, but includes common plants and animals too. NatureServe Explorer is a product of NatureServe in collaboration with the Natural Heritage Network.
ITIS Reports &#8212; ITIS (the Integrated Taxonomic Information System) is a source for authoritative taxonomic information on plants, animals, fungi, and microbes of North America and the world.
FWS Digital Media Library &#8212; The U.S. Fish and Wildlife Service&#8217;s National Digital Library is a searchable collection of selected images, historical artifacts, audio clips, publications, and video.The Chinese sturgeon (Acipenser sinensis; Chinese: 中華鱘; pinyin: zhōnghuá xún) is a critically endangered member of the family Acipenseridae in the order Acipenseriformes. Historically, this anadromous fish was found in China, Japan, and the Korean Peninsula, but it has been extirpated from most regions due to habitat loss and overfishing. It is strictly protected by the Chinese government, named a &#8220;national treasure&#8221; much like its mammalian counterpart, the giant panda. China has several conservation programmes, including reserves specifically aimed at this species and restocking through release of juveniles in the Yangtze River.

Acipenser sinensis

Arctic krill are tiny, shrimp-like crustaceans that drift in the ocean’s currents. They form part of the floating zooplankton and are eaten by many vertebrates, including fish, birds and <a href="https://www.earth.com/news/killer-whales-are-not-short-of-prey-in-southwestern-canada/">whales</a>. 



Krill have evolved a pattern of daily migration, up and down the water column, as a way of avoiding the many predators that threaten them. Their circadian rhythm involves moving to the surface of the ocean to feed at night, and then moving down into the depths during the day, to avoid detection by predators.



But how do these small crustaceans distinguish night from day during the polar winter, when the sun does not rise above the horizon?&nbsp;



In a recent study led by Jonathan Cohen from the University of Delaware, experts measured midday and midnight light intensity during winter months across the Svalbard Archipelago in the Arctic Ocean. The measurements were made from a marine research vessel, as well as from a land-based light observatory. In addition, the daily migrations of Arctic krill (Thysanoessa inermis), were monitored using acoustic recording equipment.&nbsp;



The researchers found that light availability was just two-fold higher at midday than at midnight in the middle of the Arctic winter. By comparison, midday light availability during spring and autumn is seven-fold higher than the light at midnight. The Arctic krill can detect this miniscule change in light intensity and this allows them to maintain their biological rhythms.



To support their findings in the field, the scientists also conducted lab experiments to investigate the visual sensitivity of Arctic krill to light. Using a technique called extracellular electroretinogram recording (ERG), they found that the krill were more sensitive to light at night than during the daytime.&nbsp;



This extra sensitivity helps them to identify when it is night time and then to migrate to the surface to feed. In this way, they are able to synchronize their circadian rhythms with very small variations in external light cues. Such adaptations may also be essential in regulating monthly and annual cycles of behavior and physiology, the study authors explained.



“We found that the light environment during the high Arctic polar night has a complex timing of ‘light’ and ‘dark’ due to light coming from the sun below the horizon, the moon, and the aurora borealis," said Cohen.&nbsp;



"While this light is dim and unlike the typical photoperiod at lower latitudes, we show that it is sufficient to set a biological clock in krill, showing this animal has one of the more sensitive biological rhythms studied to date.”



The study is published today in the open-access journal <a href="https://journals.plos.org/plosbiology/">PLOS Biology</a>.



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By <a href="mailto:bosman@truewan.co.za">Alison Bosman</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Arctic krill can distinguish night from day, even in polar winter

Arctic krill are tiny, shrimp-like crustaceans that drift in the...

Few places in the world showcase the overgrowth of the human population like China does. A new study published in <a href="https://www.nature.com/natsustain/">Nature Sustainability</a> looks at the environmental impact of the populous China's increasing need for <a href="https://www.earth.com/news/nutrient-profiling-system-ranks-healthy-foods/">food</a>.&nbsp;



Study lead author Hao Zhao is associated with the Integrated Biosphere Futures Research Group in the <a href="https://iiasa.ac.at/">IIASA</a> Biodiversity and Natural Resources Program.



“Assessing the impacts of future food demand requires comprehensive analyses of the agricultural sector, while tracking global environmental impacts calls for models representing trade with other regions individually. We focused on China in the global context, projecting the dynamic global future compared with other local models,”



The research predicts that demand for food in China will continue to steadily increase, especially the demand for livestock and livestock feed. To meet this demand, more land will be used for grazing and greenhouse gas emissions will increase. This also means an increasing reliance on food imports. By 2050, the paper predicts, as much as twice the agricultural land abroad will be needed to feed the growing nation.&nbsp;



By feeding China’s demand for food, the rest of the world will pay some of the environmental cost as well. On average, as much as 30 percent of a given country’s environmental challenges will be related to exports to China. In New Zealand for instance, 48 percent of agricultural land use and 33 percent of related greenhouse gases will be caused by China.&nbsp;



Various trade possibilities and greenhouse gas emissions will influence the extent of the environmental impacts associated with China’s food production. How those impacts are distributed will also depend on trade routes.&nbsp;



The researchers say that the focus should be on increasing the sustainability of agriculture at home in China. Livestock especially has a lot of room for improvement toward becoming truly sustainable.&nbsp;



“China’s rising demand for agricultural products is one of the greatest challenges on the way to reaching the Sustainable Development Goals, not only domestically, but also in China’s trading partners," said study co-author Peter Havlik.



"To reduce the global impacts, policies promoting both sustainable consumption and production need to be further pursued in China, and promoted globally, also through appropriate trade agreements."



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By <a href="mailto:zachfitzner@yahoo.com">Zach Fitzner</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

How China’s population boom will impact the environment

Few places in the world showcase the overgrowth of the...

Being able to distinguish one genetic population of plants from another is crucial for scientists working to preserve threatened populations. Until recently, lengthy and complex processes of <a href="https://www.earth.com/news/junk-dna-may-set-humans-apart-from-chimpanzees/">DNA</a> laboratory analyses were needed to be able to do this.&nbsp;



A research team from Chicago’s <a href="https://www.fieldmuseum.org/">Field Museum</a> has found a must faster method of identifying different plant populations, by using spectroradiometers - handheld devices that can record how plant leaves reflect light. As it turns out, different populations of plants reflect light differently, in ways that echo their genetic variation from each other.



“While trained biologists can usually walk into the field and identify species with their eyes, it takes expensive genetic analyses to reveal the populations - groups of individuals of the same species within a gene pool - that are so important for conservation and evolutionary research,” explained study co-lead author Dawson White, a postdoctoral researcher at the Field Museum.



“In this new study, we’ve shown that you can use light instead of DNA to define plant populations, at a similar level of detail. This new method is a lot faster and cheaper than genetic testing, which could dramatically increase our efficiency at mapping and monitoring biodiversity.”



Genetic research has shown that DNA variations among different populations of plants appear at a very fine scale. For instance, plants from one species from a mountaintop often form groups with slightly different DNA than plants from the same species located just a few miles away. When populations split, they usually don’t share pollen or seeds with each other and become genetically isolated.



Scientists generally use complex genetic analyses to distinguish such populations. However, this is an arduous task, which often takes weeks or even months. With the use of spectroradiometers - instruments that measure how much light reflects off a surface and what wavelengths the light contains – researchers can distinguish plants populations much faster.



“Leaves have evolved to interact with light, and these machines are recording differences in the light after photons have entered the leaves and been absorbed or bounced around based on different chemistry and structure,” explained White. “This instrument reads the visible and infrared light that bounces back off of the leaf, and that information can give you a tremendous amount of knowledge about the chemistry and structure of the leaf.”



According to the study, published in the journal <a href="https://nph.onlinelibrary.wiley.com/doi/abs/10.1111/nph.17731">New Phytologist</a>, the new method could prove revolutionary for attempts of conserving endangered plant populations.



“Now that we understand that each one of these mountaintops is genetically unique, that means that there are implications for conservation,” said study co-author Rick Ree. “If we want to try and maintain genetic diversity through time, especially given the shrinking habitats of alpine ecosystems due to climate change, then the implication that we should be sampling from every mountaintop.”



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Using light to identify plant populations

Being able to distinguish one genetic population of plants from...

The diet of land-based <a href="https://www.earth.com/news/scientists-explain-longevity-in-mammals/">mammals</a> is generally considered to be carnivorous, with creatures preying on other mammals within their territory. However, this is not always the case. Some mammals, such as the Brazilian jaguar, survive together harmoniously under unusual circumstances.



Researchers from <a href="https://oregonstate.edu/">Oregon State University</a> have been investigating the diet, population density, and social interactions of jaguars in a remote wetland area of Brazil.&nbsp;



Jaguars are expected to be solitary mammals, but the results of the study contradict the idea that social interactions among these animals are limited to mating and defending their territory. For example, the researchers documented adult males playing together.&nbsp;



The Brazilian population was also found to feed minimally on mammals, instead thriving on a diet of fish and aquatic reptiles.



The study was conducted by lead author Charlotte Eriksson, Professor Taal Leviwithin, and Professor Carlos Peres within a seasonally flooded area of the Northern portion of the Brazilian Pantanal, the largest freshwater wetland worldwide.



The researchers tracked a pack of the mammals in the region through motion-triggered video cameras and GPS collars. They collected samples of jaguar feces and observed the behavior of the animals while they played, fished and traveled.



Throughout the feces samples, the researchers identified nine prey items. The jaguars had diets that consisted of 55 percent aquatic reptiles, 46 percent fish,&nbsp; and only 11 percent mammals.&nbsp;



The jaguars demonstrated unusual social behaviors, moving liberally within the study area, and even playing with each other. The area of study presented a jaguar density of 12.4 per 100 square kilometers, a density which is around three times higher than the average found for other Jaguars in South American regions.&nbsp;



Across 59 camera stations that were operational for 8,065 days between 2014 and 2018, jaguars were detected on 95 percent of the cameras. Overall, the cameras captured 1,594 videos of 69 individual animals.



“Typically you see an apex predator very infrequently on camera because they move over really large areas,” said Eriksson. “Jaguars were the most frequently seen mammal on camera – which is really unusual.”



Throughout the study period, 80 social interactions were documented between adult jaguars, with 85 percent being between males and females and 12 being between same-sex jaguars. Nearly all of the same-sex interactions were male-to-male, with two males spending half an hour in front of a camera playing together.



The researchers believe that the abundance of fish and reptiles in the area is key to explaining this behavior: “If there is a lot of food around, there is less of a need to fight over it,” explained Eriksson.



The study has been published in the journal <a href="https://esajournals.onlinelibrary.wiley.com/journal/19399170">Ecology</a>.&nbsp;&nbsp;



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By <a href="mailto:calumvaughan05@gmail.com">Calum Vaughan</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Brazilian jaguars have an unexpected diet and social life

The diet of land-based mammals is generally considered to be...

According to a review of 88,125 climate-related studies, 99.9 percent of peer-reviewed articles agree that <a href="https://www.earth.com/news/climate-change-could-make-earth-inhospitable-by-2500/">climate change</a> is caused by humans. The literature was published from 2012 to November 2020.



In 2013, a similar analysis found that 97 percent of studies published between 1991 and 2012 supported the idea that human activities are the driving force behind climate change.



The findings are a stark contrast with public representatives and opinion polls which falsely suggest that a significant debate still exists among scientists over the causes of climate change. In 2016, for instance, the <a href="https://www.pewresearch.org/">Pew Research Center</a> found that less than 27 percent of U.S. adults believed that scientists agreed that climate change is caused by human activity.



A research team led by <a href="https://www.cornell.edu/">Cornell University</a> began by examining a random sample of 3,000 studies from the larger dataset and found that only four of them were skeptical about the role that human activities play in promoting global warming.&nbsp;



“We knew that [climate skeptical papers] were vanishingly small in terms of their occurrence, but we thought there still must be more in the 88,000,” said study lead author Mark Lynas,&nbsp;a visiting fellow at the <a href="https://allianceforscience.cornell.edu/">Alliance for Science</a> at Cornell University.



“To understand where a consensus exists, you have to be able to quantify it. That means surveying the literature in a coherent and non-arbitrary way in order to avoid trading cherry-picked papers, which is often how these arguments are carried out in the public sphere."



With the assistance of Simon Perry, a software engineer and volunteer at the Alliance for Science, the researchers created an algorithm that searched keywords from articles the team knew they were skeptical, such as “natural cycles,” “cosmic rays,” or “solar.” After applying the algorithm to the entire dataset, they found only 28 implicitly or explicitly skeptical papers, all published in minor journals.



“We are virtually certain that the consensus is well over 99 percent now and that it’s pretty much case closed for any meaningful public conversation about the reality of human-caused climate change,” said Lynas.&nbsp;



“It's critical to acknowledge the principal role of greenhouse gas emissions so that we can rapidly mobilize new solutions, since we are already witnessing in real time the devastating impacts of climate related disasters on businesses, people and the economy,” concluded study co-author Benjamin Houlton, Dean of the <a href="https://cals.cornell.edu/">College of Agriculture and Life Sciences</a> at Cornell.



The study is published in the journal <a href="https://www.pewresearch.org/">Environmental Research Letters</a>.



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

The debate is over: humans caused climate change

According to a review of 88,125 climate-related studies, 99.9 percent...

According to a new <a href="https://drive.google.com/file/d/1GBpG1A-Bf_quuU67OQgNmINwiYR0IM2r/view">report</a> published by United Nations’ <a href="https://globalabc.org/">Global Alliance for Buildings and Construction</a>, the economic consequence of the COVID-19 pandemic caused CO2 <a href="https://www.earth.com/news/feeding-cattle-seaweed-could-reduce-methane-emissions/">emissions</a> from buildings and construction to decrease significantly in 2020. However, the pandemic recovery spending has not sufficiently prioritized climate friendly approaches that would help decarbonize the building sector and mitigate greenhouse gas emissions in the future. 



Recent decades witnessed a large growth in the buildings sector, which caused a significant increase in greenhouse gas emissions. According to the UN report, this sector accounted for 37 percent of energy-related CO2&nbsp;emissions in 2020.&nbsp;



While the 2020 level of emissions was ten percent lower than in 2015, experts claim that the reduction was temporary and was associated with pandemic-related lockdowns, slower economies, and less construction activity. Unfortunately, the emission levels have already started to increase again in 2021 with the relaxation of restrictions.



“This year showed that climate change is an immediate direct threat to every community on this planet, and it is only going to intensify,” said Inger Andersen, Executive Director of the <a href="https://www.unep.org/">United Nations Environment Programme</a>.



“The buildings and construction sector, as a major source of greenhouse gas emissions, must urgently be decarbonized through a triple strategy of reducing energy demand, decarbonizing the power supply, and addressing building materials’ carbon footprint, if we are to have any chance of meeting the Paris Agreement goal of limiting global warming to 1.5C.”



In order to achieve the goal of net-zero emissions by 2050, the&nbsp;<a href="https://www.iea.org/">International Energy Agency</a>&nbsp;claims that direct building CO2&nbsp;emissions need to decrease by 50 percent, and that indirect building sector emissions will have to be reduced by 60 percent.&nbsp;



To reach this goal, increased efforts should be put in decarbonizing buildings while increasing their resilience. Governments should commit to further decarbonize the power, heating, and cooling energy supply, while investment in building efficiency should steadily rise and expand beyond direct government investment to private investors.&nbsp;



Furthermore, the scope and coverage of building energy codes related to design, heating, cooling, ventilation system, and appliances, also needs to increase. Finally, the interventions to reduce the climate impact of existing buildings should be combined with investments in adaptation and resilience measures.&nbsp;



Without taking all these factors into account, emissions related to buildings and construction activity will continue to rise and contribute to dangerous climate change.&nbsp;&nbsp;



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Building sector emissions are on the rise

According to a new report published by United Nations’ Global...

A new study from the <a href="http://www.buffalo.edu/">University of Buffalo</a> has gone underground to investigate how forests will respond to the pressures of climate change. The experts report that what happens beneath the forest - particularly when it comes to <a href="https://www.earth.com/news/groundwater-has-a-larger-impact-on-ocean-chemistry-than-expected/">groundwater</a> availability - is very important in determining its fate.



According to the researchers, models used in forest mortality projections do not account for the sideways flow of water through soil. This is a strong indicator of the resilience of riparian forests in a warming climate.&nbsp;



“There hasn’t been a lot of attention on groundwater and how the movement of water from one location to another below ground can impact plants’ survival prospects, making some locations drier, and others wetter,” explained study lead author Dr. Xiaonan Tai.



“Groundwater is a hidden water source for ecosystems that people have neglected over the years: It is very hard to observe and quantify, just because we can’t see it. The contribution of our new research is to begin characterizing lateral groundwater processes and quantifying how much of a role they can have in terms of influencing the future of forests.”



The researchers incorporated information about groundwater into computational models that predict the future outcomes of forests.



“Our research will fundamentally change the way the Earth systems modeling community will think about the impacts of future climate change droughts on forests,” said Professor Scott Mackay.&nbsp;



“In essence, the various vegetation models out there today assume the world is flat. Our model changes the story by allowing for water to be moved laterally below the surface, while simultaneously modeling the physiological responses of trees on the landscape.”



The study examined the potential outcomes for a riparian cottonwood forest in Alberta, Canada, with a particular focus on the last 20 years of this century.



The results of the study suggests that the amount of water saved for future use may not be as great as expected.&nbsp;



“Once you introduce subsurface lateral water flow, there is still extra saved water, but that saved water won’t all stay local,” explained Dr. Tai. “Some of it will move away, and once it’s gone, plants won’t be able to use it in future droughts.”



In addition, models that fail to consider horizontal water flow may overestimate other mortality risks, noted Professor Mackay.



“Within the soil, water can move in all directions from areas of high water content to areas of low water content. This is pronounced in mountainous landscapes because water moves from high to low elevation, and in close proximity to water bodies, such as one finds in river floodplains."



“By moving the water around horizontally, locations that would otherwise be very dry when the rain stops are made wetter, while areas that are typically wet can afford to give up some water without harming the plants," explained Professor Mackay.



The study authors concluded that if scientists and policymakers want to understand whether riparian forests will survive future warming, they must think more about hydrology and the hard-to-see processes that occur beneath the forest floor.



The study is published in the journal <a href="https://iopscience.iop.org/journal/1748-9326">Environmental Research Letters</a>.



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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Secrets of forest mortality can be found underground

A new study from the University of Buffalo has gone...

A new study published in the journal&nbsp;<a href="https://journals.aps.org/prfluids/abstract/10.1103/PhysRevFluids.6.100502">Physical Review - Fluids</a> has found that marshes, which are ubiquitous along the world’s shorelines, could play a significant role in mitigating the damage caused by storms and <a href="https://www.earth.com/news/sea-levels-are-rising-at-an-alarming-rate/">sea level rise</a>.&nbsp;



By combining laboratory experiments that use simulated marsh plants in a large, 24-meter-long wave tank with mathematical modeling, a research team led by the <a href="https://www.mit.edu/">Massachusetts Institute of Technology</a> (MIT) discovered that marsh plants provide a positive feedback cycle that helps not only to stabilize but also build up delicate coastal lands, making them more resilient to extreme events caused by climate change.



“When you go to a marsh, you often will see that the plants are arranged in zones,” explained study senior author Heidi Nepf, a professor of Fluid Mechanics at MIT. “Along the edge, you tend to have plants that are more flexible, because they are using their flexibility to reduce the wave forces they feel. In the next zone, the plants are a little more rigid and have a bit more leaves.” As the zones progress, the plants will gradually become leafier, stiffer, and more effective at absorbing wave energy.



Although the protective capacities of marsh plants against inclement weather have already been well-understood, this study is the first to incorporate details of plant morphology, such as the number and spacing of flexible leaves and stiffer stems, as well as the complex interactions of currents and waves coming from various directions, to find out how much marshland with what types of plants would be needed to provide optimal levels of protection. Furthermore, it can also provide a quantitative way to estimate the value provided by marshes.



&nbsp;“It could allow you to more accurately say, ‘40 meters of marsh will reduce waves this much and therefore will reduce overtopping of your levee by this much,’” said Nepf. “Someone could use that to say, ‘I’m going to save this much money over the next 10 years if I reduce flooding by maintaining this marsh.’ It might help generate some political motivation for restoration efforts.”



Professor Nepf is already trying to include some of these findings in coastal planning processes, by working on a practitioner panel at the <a href="https://thewaterinstitute.org/">Water Institute of the Gulf</a>, which serves the storm-ridden Louisiana coastline. “We’d like to get this work into the coastal simulations that are used for large-scale restoration and coastal planning,” she concluded.



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Marshes protect shorelines against inclement weather

A new study published in the journal&nbsp;Physical Review - Fluids...

As human activities alter the environment at an accelerating rate, scientists are scrambling to understand how animals will respond. A new study from the <a href="https://www.helsinki.fi/en">University of Helsinki</a> has investigated which human-induced environmental changes that <a href="https://www.earth.com/news/islands-are-not-evolutionary-dead-ends-for-animals/">animals</a> are the most sensitive to, and how these changes will alter their behavioral patterns.



"Currently, human-induced rapid environmental change (HIREC) is exposing organisms to novel selection pressures that are vastly different from those experienced previously," wrote the study authors.&nbsp;



"Whilst evolutionary responses to environmental change can occur quickly and buffer the ability of species to persist in a changing environment, behavioral responses are often the initial response of organisms to change."



The researchers noted that understanding how an animal's behavior will be modified by environmental change is critically important.&nbsp;



"In response to environmental change, organisms can adapt, relocate and/or acclimatise. First, populations can respond to changing environments at a genetic level, through evolutionary adaptation resulting from selection," said the researchers.



"Secondly, organisms can relocate via dispersal into habitats in different geographic spaces in response to environmental factors such as temperature and resource availability."&nbsp;



"Finally, organisms can acclimate through phenotypic plasticity, which may be physiological, morphological or behavioral."



According to the experts, behavioral plasticity allows organisms to respond to environmental changes very quickly by modifying their behavior to better suit the new conditions.



The study was focused on data from more than one hundred animal species, including fish, birds, insects, amphibians and mammals. The experts found that all of the behavioral traits examined - such as aggression, boldness, sociability and activity - were significantly changed by environmental changes.



“The biggest change was seen in the animals’ activity in exploring their environment. Animals have a strong response to all forms of environmental change, but climate change engendered the greatest change in animal behavior,” explained study co-author Petri Niemelä.



Beyond climate change, the researchers considered changes in carbon dioxide concentration, fluctuations in nutrient levels, and invasive species. Direct human impacts like urbanization were also modeled.&nbsp;



Overall, the experts concluded that modifications in activity or other behavior are often the initial response to climate change. They determined that more research is needed on individual populations to gain a better understanding of how animals respond to environmental changes.&nbsp;



“Behavioral change can serve as a buffer with which animals avoid the immediate negative effects of environmental change," said Niemelä.&nbsp;



"For instance, such change can compensate for low reproductive success or increased mortality caused by environmental change. By changing their behavior, animals can also gain more information on the altered environment.”



The study is published in the journal <a href="https://onlinelibrary.wiley.com/journal/16000706">Oikos&nbsp;</a>



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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Environmental change makes animals alter their behavior

As human activities alter the environment at an accelerating rate,...

Spread throughout the upper 100 meters of the <a href="https://www.earth.com/news/dragonflies-may-migrate-across-the-indian-ocean/">ocean</a>, microscopic phytoplankton are known to be as important in modifying the planet’s carbon cycle as all the land plants combined. With this in mind, a team of scientists from <a href="https://www.sun.ac.za/">Stellenbosch University</a> set out to establish whether phytoplanktonic organisms are active in the Southern Ocean during the Antarctic winter months.



Until their study, not much was known about the conditions that characterize the Southern Ocean during the winter, or whether phytoplankton become dormant during this time. The conditions turned out to be very challenging, with sub-zero temperatures and freezing, gale force winds - not to mention the enormous waves that sometimes towered as high as 20 meters.&nbsp;



Under these conditions, oceanic sampling is rarely conducted. Therefore, knowledge about the wintertime activity of the phytoplanktonic organisms has been very limited.&nbsp;



During July and August 2017, a research team from Stellenbosch University’s Center for Trace and Experimental Biogeochemistry (TracEx) conducted the most comprehensive winter study in the Southern Ocean to date.



Sampling was conducted from the South African polar research vessel SA Agulhas II and the trip was funded by the South African National Antarctic Program (SANAP), the Department of Forestry, Fisheries and the Environment (DFFE), and the National Research Foundation (NRF).&nbsp;



The scientists found that phytoplankton are indeed active during the icy cold, dark winter months. Dr Ryan Cloete, a postdoctoral fellow in SU’s Department of Earth Sciences and first author of two recent publications on the topic, says their findings are contrary to the general view that the Southern Ocean is biologically dormant during winter.



“Akin to leaves falling off trees during autumn because of unfavourable growth conditions, the assumption was that phytoplankton would also not be active during the winter. One of our major findings is that phytoplankton are indeed active during winter in the Southern Ocean, although not to the levels we see in summer. How phytoplankton are able to adapt to winter conditions is not well understood, and our research on trace nutrients is the first step in figuring out these adaption strategies,” he explains.



Apart from photosynthesizing, which results in a net intake of carbon dioxide and the production of oxygen into the atmosphere as a by-product, phytoplankton are critical producers in the oceanic food chain. They form food for zooplankton, such as krill, which are then eaten by fish, seals, penguins, whales and other consumers.



Dr. Cloete explained that the winter season in the Southern Ocean is extremely important for setting the biological stage for the spring and summer seasons.



“In winter, strong storms and winds serve to create a more unstable surface layer which penetrates beneath the stable summer surface waters, which are now depleted in nutrients after the growing season. This allows mixing with the nutrient rich waters found in the sub-surface waters," said Dr. Cloete.



"With the help of increased sunlight hours and calmer seas, this winter pulse of nutrients to the surface helps catalyze and sustain spring and summer phytoplankton blooms which, in turn, attracts whales, dolphins and penguins to the Southern Ocean."



“Observing winter systems is helping us understand various adaptation and survival strategies of phytoplankton under adverse growth conditions as well as nutrient recharge processes in extreme nutrient depleted surface waters at the end of the summer season. This is extremely important as the Southern Ocean circulation hub dictates that these waters are transported northwards, influencing ocean productivity throughout much of the global low-latitude ocean."



This global process involves the movement of large volumes of water, via the ocean’s current systems. At the poles, the cold and dense surface seawater sinks to the deep ocean, from where it flows in large ocean currents to eventually return to the surface through mixing and wind-driven upwelling in the warmer latitudes. Scientists call this the great ocean conveyor belt, and it can take water almost a thousand years to complete the journey. The Southern Ocean acts as a central hub whereby inflowing waters are modified and redistributed throughout the global ocean.



In addition, the Southern Ocean plays a fundamentally important role in regulating Earth’s climate. “It is estimated to store about 75 percent of the global oceanic uptake of excess heat and 35 percent of the global uptake of excess carbon from the atmosphere," said Dr. Cloete. "The Southern Ocean is also the only ocean that directly connects the three major ocean basins; the Pacific, Atlantic and Indian Oceans. In other words, what happens in the Southern Ocean has an impact on the global ocean.”



The findings are important because they give a more complete picture of the atmosphere-to-ocean carbon transfer cycle over all seasons. Global climate models are currently based predominantly on data from spring and summer seasons, so the addition of data from winter will make models more representative. For scientists, this is a step forward in analysing the sensitivity of this transfer to climate change.



Professor Alakendra Roychoudhury is a specialist in environmental and marine biogeochemistry at SU and head of the TracEx research group. He said that the findings reaffirm the&nbsp;<a href="https://theconversation.com/an-ocean-like-no-other-the-southern-oceans-ecological-richness-and-significance-for-global-climate-151084">Southern Ocean’s global influence</a>&nbsp;in regulating the climate and the marine food web.



“The earth system is intricately coupled through physical, chemical and biological processes with self-correcting feedback loops to modulate variability and negate climate change," said Professor Roychoudhury. "Our research is a prime example of this coupling where biochemical processes happening at microscopic level at the interface of water and microorganisms, is influenced by large scale ocean circulation and mixing."



The study is published in the journal <a href="https://www.journals.elsevier.com/marine-chemistry">Marine Chemistry</a>.



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By <a href="mailto:bosman@truewan.co.za">Alison Bosman</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

The Southern Ocean has a strong influence on the carbon cycle

Spread throughout the upper 100 meters of the ocean, microscopic...

Nearly half a million deaths each year are caused by mosquito-borne diseases. Recently, the Swedish startup <a href="https://www.molecular-attraction.com/">Molecular Attraction</a> developed a way of tricking mosquitoes into drinking poisoned beet juice that contains a molecule isolated from malaria-infected blood, and thus mimics the human blood that mosquitoes are so highly attracted to.&nbsp;



<a href="https://www.earth.com/news/climate-change-malaria-colder-areas/">Malaria</a> is an infectious disease caused by the Plasmodium falciparum parasite that commonly infects Anopheles mosquitoes, which in turn transmit it to humans. Victims develop fevers, headaches, chills, nausea, and vomiting, symptoms that often lead to severe organ damage and even death. Out of millions of people infected with malaria each year, almost 400,000 die, including a large number of children under the age of five.&nbsp;



Startup cofounder Noushin Emami, a professor of Molecular Biosciences at <a href="https://www.su.se/cmlink/stockholm-university">Stockholm University</a> was the first to discover that blood which contains the malaria parasite is more attractive to mosquitoes than regular blood. This appeared to be caused by the presence of a molecule called HMBPP which releases a smell that attracts mosquitoes and stimulates them to drink more blood.



“It turns out that HMBPP can force mosquitoes to drink almost anything, as long as the pH is right,” said Lech Ignatowicz, co-founder and CEO of Molecular Attraction. “The big advantage is that HMBPP doesn’t attract other insects or other species. So you can use it as a passive way of convincing mosquitoes to eat toxins.”



Unlike the harmful pesticides that have been sprayed on extended areas throughout history in order to eradicate mosquitoes, the new substance containing the HMBPP molecule is not damaging to the environment and is designed specifically for attracting the Anopheles mosquitoes that are responsible for spreading malaria. Moreover, it is not designed to eliminate mosquitoes completely – an important aspect, considering that they have fundamental roles in various ecosystems, regardless of their disease-carrying ability.



“We want to eliminate diseases they carry,” said Professor Ignatowicz. “And also limit the amount of mosquitoes in proximity to people. So we can create, let’s say, a mosquito-free zone around your house, but we shouldn’t eliminate them completely from your state.”



The company’s aim is to make this product, which “showed potential as an effector in environmentally friendly vector-control strategies,” accessible and affordable to a large number of people from the most vulnerable countries.



The study is published in the journal <a href="https://go.skimresources.com/?id=55199X1584066&amp;isjs=1&amp;jv=15.2.0-stackpath&amp;sref=https%3A%2F%2Fwww.dailymail.co.uk%2Fsciencetech%2Farticle-10097095%2FScientists-trick-malaria-carrying-mosquitoes-drinking-toxic-beet-juice-think-blood.html&amp;url=https%3A%2F%2Fwww.nature.com%2Farticles%2Fs42003-021-02689-8&amp;xguid=&amp;xs=1&amp;xtz=-180&amp;xuuid=8008718213b68f3ccd40c0307a12e72b&amp;xjsf=other_click__auxclick%20%5B2%5D">Communications Biology</a>.&nbsp;



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Mosquitoes can be tricked into drinking toxic substances

Nearly half a million deaths each year are caused by...

While restrictions are eased and borders are opened across the globe, new research shows that the emergence of the Delta and "Delta Plus" variants of SARS-CoV-2 could result in the <a href="https://www.earth.com/news/the-pandemic-has-had-an-enormous-impact-on-public-health-services/">pandemic</a> being prolonged further if strategic "heterologous vaccination" is not put in action.



The researchers studied the mutations present in Delta and Delta Plus, concluding that the Delta was immune to one-in-four antibody groups produced by natural immunity and vaccines, with Delta Plus being resistant to one out of two.



"It is conceivable that by fusing cells in the respiratory tract, the Delta variant may spread more efficiently and induce more damage. This could contribute to a more severe course of COVID-19," explained study lead author Arora Prerna.



However, it was discovered that individuals vaccinated with a single dose of both Oxford-AstraZeneca and BioNTech-Pfizer showed significantly higher immunity than those with two doses of Oxford-AstraZeneca.



The research team used cell culture experiments to come to this conclusion, finding that Delta is most resistant against the monoclonal antibody balmlanivimab, with Delta Plus being resisting to both balmlanivimab and etesimab. As a result, Delta and Delta Plus were less well inhibited by antibodies from vaccinated and infected individuals when compared to the original COVID-19 virus, resulting in the rapid spread of the variants.



"This means that vaccination likely confers comparable protection against Delta and Delta Plus and that Delta Plus is not significantly more dangerous than Delta," explained Stefan Pöhlmann.



Across Europe, BioNTech-Pfizer is the most commonly used vaccine, followed by Oxford-AstraZeneca. In Germany, rare side effects associated with Oxford-AstraZeneca have resulted in the recommendation that BioNTech-Pfizer is used as the second vaccination dose to anyone who has already received a dose of Oxford-AstraZeneca, a strategy known as ‘heterologous vaccination’



"Our results are consistent with the observation that vaccination efficiently protects against the development of severe disease after infection with the Delta variant, but frequently fails to completely suppress infection," said Stefan Pöhlmann.



"In light of the efficient protection against severe disease, the goal continues to be a high vaccination rate. This can prevent the health care system from being overwhelmed in case of increased spread of Delta and closely related viruses during the winter months."&nbsp;



"Our studies show that heterologous vaccination induces significantly more neutralizing antibodies to Delta than two vaccination shots with Oxford-AstraZeneca. Individuals who have received such a heterologous vaccination may have a very good immune protection against Delta and Delta Plus," said Markus Hoffmann.



The study was conducted through a collaboration between the <a href="http://goettingen-campus.de/dpz">German Primate Center’s Leibniz Institute for Primate Research in Göttingen</a>, the Hannover Medical School, The University of Göttingen Medical Center, and the Friedrich-Alexander University of Erlangen-Nürnberg.



The research is published in the journal <a href="https://www.cell.com/cell-reports/home">Cell Reports</a>.&nbsp;



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By <a href="mailto:calumvaughan05@gmail.com">Calum Vaughan</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Delta variants could further prolong the Covid pandemic

While restrictions are eased and borders are opened across the...