Belugas have to dive deeper for food as a result of sea ice loss
As sea ice loss contributes directly to polar bear population declines, less is known about how less sea ice impacts marine habitats and other wildlife.
A first-ever study found that beluga whales are diving deeper and for longer periods as a result of melting sea ice caused by climate change.
Researchers from the University of Washington examined how Arctic whale species like belugas are indirectly affected by sea ice loss in the Arctic.
Their research, published in the journal Diversity and Distributions, shows that beluga whales have changed their hunting patterns in the Arctic, but whether this is a positive for the species remains to be seen.
“I think this paper is novel in that we’re presenting some of the first indirect effects of sea ice loss for an Arctic whale species,” said Donna Hauser, the study’s lead author. “As changes in sea ice affect oceanographic properties, that could be affecting the distribution, abundance or species composition of prey for belugas.”
The researchers focused on two populations of belugas who spend their winters in the Bering Sea and travel north to hunt during the summer season in the Beaufort and Chukchi seas.
The populations were monitored and tracked with satellite-linked tags during their summer migrations, and the study includes two different periods where data was collected from.
The early period followed the belugas from 1993 to 2002 and the late period followed the populations from 2004 to 2012.
This allowed the researchers to observe how the changing landscape and sea ice loss affected the populations during their summer hunting season.
“We have documented loss of sea ice and reductions of habitat for Arctic marine mammals across most of the circumpolar Arctic, so this area is not unique,” said Kristin Laidre, a co-author of the research. “We’re seeing this ice loss broadly in all areas where belugas occur.”
For the population whose tags recorded dive depth, the Chukchi belugas, the loss of sea ice caused the later populations to dive deeper to get food.
Average dive depth between the early and late periods changed from 164 feet to 210 feet, and the Chukchi belugas dove around three times a day for longer periods than in earlier years.
The researchers say this change is likely because the prey that belugas hunt are affected by the loss of sea ice and have either been dispersed or driven deeper in response.
There’s also a possibility that this is good news for the beluga populations.
“Reduced sea ice cover over a longer period over the summer could mean improved foraging for belugas,” said Hauser. “But it’s also important to recognize these changes in diving behavior are energetically costly.”
Whether the loss of sea ice is benefitting beluga whale populations is still not yet clear, and further research will be needed in order to fully understand the indirect ramification sea ice loss has on Arctic habitats and wildlife.
Image Credit: Laura Morse/Alaska Fisheries Science Center, NOAA Fisheries Service
Sea urchins erode reef rock, may pose a threat of bioerosion
Sea urchins are spiny marine creatures that live in high densities on rocky temperate reefs. While also a hazard to barefoot beachgoers, researchers have reason to believe that these creatures may be a hazard to the reefs themselves. Although no experimental data had yet proved it, scientists had long wondered if urchins excavate the rock they reside on through their grazing activity. If so, they may pose a significant bioerosion threat to temperate reefs.
The authors of a new study published in the open-access journal PLOS ONE investigated this question through monitoring purple sea urchins (Strongylocentrotus purpuratus) on flattened rock surfaces in a lab. Using fine- and medium-grain sandstone, mudstone, and granite rocks taken from Californian reef sites naturally occupied by sea urchins, the researchers compared their lab measurements to field measurements.
Their results showed that sea urchins did visibly excavate the rock in the laboratory experiment. Excavation rates varied greatly by rock type – each urchin excavated roughly 32 grams of medium-grain sandstone in the course of a year, but granite excavation was 37 times slower. However, these differences were reflected in field measurements as well. The minor differences were that the granite pits were shallower and the sea urchins were flatter than their sandstone counterparts.
The researchers combined the laboratory rates with urchin density measurements, and estimate that on medium-grain sandstone reefs, urchins might produce almost 200 tons of sediment per hectare per year. Although excavation rates in the field might differ greatly from laboratory rates. Still, the authors believe that urchin-mediated bioerosion could be a significant factor in temperate reef coastal erosion.
“What shocked us was the rate of bioerosion – particularly on sandstone,” says lead author Michael Russell of Villanova University. “In the course of feeding, sea urchins scrape the rock surface using their self-sharpening, regenerating teeth, which act as ‘rock picks’ and this process results in the excavation of pits.” While it may seem minor on an individual level, these small scrapings add up with high-density populations of urchins over time. The authors believe this issue is worth further investigation in order to help maintain our reefs.
Image Credit: Michael Russell
Climate models show future extreme weather for European cities
In an unprecedented study, researchers at Newcastle University have projected changes in heat waves, droughts, and flooding for every European city using all available climate models.
The experts are reporting that heat waves will become worse in all 571 cities and drought conditions will increase as well, particularly in southern Europe.
River flooding will become more frequent and severe, with the worst projections in northwestern European cities. In the best case scenario, 85 percent of cities in the UK with a river will still face increased flooding.
The team developed three possible future cases which they referred to as the low, medium, and high impact scenarios. Even for the lowest impact scenario, the number of heat wave days and maximum temperatures will rise for every city in Europe.
The high impact scenario predicts that 98 percent of European cities will experience more intense droughts in the future, and cities in southern Europe may face droughts that are 14 times worse than today.
“Although southern European regions are adapted to cope with droughts, this level of change could be beyond breaking point,” said lead author Dr. Selma Guerreiro.
“Furthermore, most cities have considerable changes in more than one hazard which highlights the substantial challenge cities face in managing climate risks.”
Study co-author Professor Richard Dawson says that the study has far-reaching suggestions in terms of how Europe adapts to climate change.
“The research highlights the urgent need to design and adapt our cities to cope with these future conditions,” said Professor Dawson.
“We are already seeing at first hand the implications of extreme weather events in our capital cities. In Paris the Seine rose more than 4 metres above its normal water level. And as Cape Town prepares for its taps to run dry, this analysis highlights that such climate events are feasible in European cities too.”
The Intergovernmental Panel on Climate Change (IPCC) will hold its first Cities and Climate Change Science Conference next month to emphasize the major roles that cities must play in climate change mitigation.
“A key objective for this conference is to bring together and catalyze action from researchers, policy makers and industry to address the urgent issue of preparing our cities, their population, buildings and infrastructure for climate change.”
The research is published in the journal Environmental Research Letters.
Another round of earthquakes reported at Yellowstone supervolcano
The Yellowstone supervolcano is making headlines yet again with a new swarm of earthquakes that started on February 8th.
In the past ten days, there have been more than 200 events, but seismologists say the activity is still weak and that there’s little to be alarmed about.
The United States Geological Survey (USGS) reported that none of the mini-quakes have been strong enough to be felt and are occurring roughly five miles below the surface.
“Swarms like this account for more than 50% of the seismic activity at Yellowstone, and no volcanic activity has occurred from any past such events,” says the USGS Yellowstone Volcano Observatory weekly column. “As of the night of February 18, over 200 earthquakes have been located in an area.”
The site of the activity coincided with last year’s Maple Creek Swarm, which resulted in approximately 2,400 earthquakes, and this current round may just be a continuation of that period of activity.
The Yellowstone Caldera underneath Yellowstone National Park is a hotbed of seismic activity.
Several faults lie beneath the wilderness reserve and swarms are not uncommon in areas like Yellowstone where small changes and stress along the faults create a string of earthquakes.
The geological processes responsible for the current swarm are a combination of movement along the fault lines and pressure changes deep below the surface.
“Swarms reflect changes in stress along small faults beneath the surface, and generally are caused by two processes: large-scale tectonic forces, and pressure changes beneath the surface due to accumulation and/or withdrawal of fluids (magma, water, and/or gas),” states the Yellowstone Observatory Column.
While seismic activity is not uncommon and this present swarm is not yet a cause for concern, USGS seismologists get an opportunity to finetune their monitoring methods and research.
The Pacific Northwest is expected to become progressively warmer
The Intergovernmental Panel On Climate Change (IPCC) has developed a “business-as-usual” baseline case, which assumes that future development trends will follow those of the past with no significant policy changes.
In this scenario, atmospheric carbon dioxide (CO2) could rise in excess of 900 parts per million, which is more than double the current level of CO2 concentrations. Global mean temperatures will increase by between 1.5 and 7 degrees Celsius, and there will be less precipitation in the summer yet more in the winter.
The researchers teamed up with experts at the U.S. Forestry Service for their investigation into future climate conditions in the Pacific Northwest.
The study was focused on four types of outputs from over 30 climate models. Each climate projection was based on data which had been converted through a process called downscaling, a method of obtaining weather and climate information on a local scale.
The four climate projections predicted the same temperature rise in the region within 0.3 degrees Celsius.
“From a regional perspective, the differences in projected future changes are minor when you look at how much each projection says climate will change for the business-as-usual scenario,” said lead author Yueyang Jiang.
“The climate projections were created using different downscaling methods, but the projected changes in climate among them are similar at the regional scale.”
The researchers analyzed the climate of the recent past and compared it to three separate time frames between 2011 and 2100. Their goal was to characterize the differences to provide guidance for land managers and scientists who are evaluating the projected impacts of climate change on local resources.
Study co-author John Kim said that the analysis reveals “a fairly consistent high-resolution picture of climate change.”
The research team confirmed that the downscaling process had little or no effect on the accuracy of the data.
“So, individuals and organizations that are interested in how much climate may change for most parts of the region can use any of the datasets we examined,” said Kim.
The study is published in the journal Scientific Data.
Sea level rise is imminent, but we can control its severity
The Paris Climate Accord aims to reduce emissions and halt future temperature increases so that warming does not exceed 2 degrees Celsius.
But a new study from the Potsdam Institute for Climate Impact Research has outlined the likely sea level rise that will occur even if the Paris Climate Agreement goals are met and followed through.
There’s a certain point of no return where no matter what we do to combat climate change, the ramifications of past emissions will still be felt as the years go on.
This is not to say that the Paris Accord is a futile exercise. In fact, the new research shows that the sooner emissions reach their peak and decrease the less drastic sea level rise will be.
“Human-made climate change has already pre-programmed a certain amount of sea-level rise for the coming centuries, so for some, it might seem that our present actions might not make such a big difference – but our study illustrates how wrong this perception is,” said Matthias Mengel, the lead author of the study.
The results show that for every five years that emissions are not reduced between 2020 and 2035, sea level could rise an additional 20 centimeters.
If the goals of the Paris Climate Agreement are met and sustained until 2030, the researchers found that sea levels could rise between .7 and 1.2 meters.
For the study, the research team created a model of seal level rise and climate in order to test different scenarios where emissions peaked at different times using the goals and parameters set by the Paris Agreement.
There are many different factors including melting glaciers, expanding ocean water, warmer temperatures, and ice sheet loss that can contribute to sea level rise. The scientific community is still largely unsure of how ice sheets in the Antarctica And Greenland will be affected by climate change.
The results showed that even if the Paris Accord caps emissions right away, ice sheet loss from Antartica is still possible.
The research highlights the importance of taking immediate action against climate change and capping emissions, as delays would result in higher and higher sea level rise.
“The Paris Agreement calls for emissions to peak as soon as possible,” said Carl-Friedrich, a co-author of the study. “For millions of people around the world living in coastal areas, every centimeter can make a huge difference – to limit sea-level rise risks immediate CO2 reduction is key.”
1965: The year human-induced changes to Earth officially began
For the first time, researchers have found scientific evidence to pinpoint when mankind entered into the current geological age known as the Anthropocene. A radiocarbon spike located in the heartwood of a Sitka spruce tree represents the precise time in 1965 that humans changed our planet forever.
Many scientists agree that we have entered into a new epoch marked by human-induced changes to the Earth, which is referred as the Anthropocene. In order for a new era to be declared, however, there has to be a clear, global signal that marks its official beginning.
The radioactive carbon spike, which was created by atmospheric thermonuclear bomb tests in the 50s and 60s, has provided experts with the proof that they have been searching for.
Study co-author Christopher Fogwill is a professor of Glaciology and Palaeoclimatology at Keele University.
“The impact that humanity’s nuclear weapons testing has had on the Earth’s atmosphere provides a global signal that unambiguously demonstrates that humans have become the major agent of change on the planet,” said Professor Fogwill.
“This is an important, yet worrying finding. The global atomic bomb signal, captured in the annual rings of this invasive tree species, represents a line in the sand, after which our collective actions have stamped an indelible mark, which will define this new geological epoch for generations to come.”
The Sitka spruce tree, located on Campbell Island in the Southern Ocean, is over 100 years old and native to the North American Pacific Coast. It was planted on the island in 1901 by the governor of New Zealand. The spruce is referred to as the “loneliest tree in the world” because it stands over 100 miles away from the nearest tree on the Auckland Islands.
“It seems somehow apt that this extraordinary tree, planted far from its normal habitat by humans has also become a marker for the changes we have made to the planet, it is yet further evidence, if that was needed, that in this new epoch no part of our planet remains untouched by humans,” said study co-author Mark Maslin.
Professor Chris Turney from the University of New South Wales is the study’s lead author.
“We were incredibly excited to find this signal in the Southern Hemisphere on a remote island, because for the first time it gave us a well defined global signature for a new geological epoch that could be preserved in the geological record,” said Professor Turney.
“Thousands of years from now this golden spike should still stand as a detectable marker for the transformation of the Earth by humankind.”
Although evidence of the radiocarbon peak had been previously found preserved in European trees, the signal did not yet qualify as the marker of a new epoch.
Now that the signature has also been identified in the Southern Hemisphere, it is considered an official signal because it is global, precise, and detectable in the geological record.
The study is published in Scientific Reports.
Grazing lands are extremely vulnerable to climate change
According to researchers at the University of Minnesota, precipitation variability over the past century has significantly affected 49 percent of the world’s grazing lands. Yearly changes in rainfall are limiting the ability of vegetation to support large herds of farm animals.
Across the globe, 800 million people depend on livestock for income and food security. Grasses and plants cannot flourish in a dry season and animals suffer as well, subsequently impacting the people who depend on these agricultural systems.
The researchers used climate data from 1901 to 2014 to map the progression of precipitation variability across the globe. Their model showed that some grazing lands had experienced gradual decreases in rainfall variability, but the predominant trend was found to be an increase in short-term rainfall fluctuations.
Lindsey Sloat is a postdoctoral research associate with IonE’s Global Landscapes Initiative and the study’s lead author.
“Visualizing precipitation variability trends allows us to identify grazing lands that have undergone large changes – and to learn from those places where people have managed to adapt well despite increased variability,” said Sloat.
Grazing lands already tend to be unsuitable for crops because they are either too dry or have poor soils, and some grazing lands are more inhospitable than others.
Study co-author Paul West explained that even small changes in rainfall patterns put these vulnerable grazing lands further at risk.
The researchers determined that regions with high year-to-year precipitation variability support lower livestock densities. They also found the most precipitation variability in areas where grazing is critical for food security.
In addition, the study revealed that global grazing lands endure 25 percent more year-to-year rainfall variability than the average global surface land area.
“This study is showing us that grazing is potentially highly vulnerable to climate change, right across the world, from Australia to Central Asia, sub-Saharan Africa and the Americas,” said co-author Mario Herrero.
The research is published in in Nature Climate Change.
Plants first began covering the Earth 520 million years ago
Until now, it had been widely believed that plants first colonized the planet 420 million years ago, creating lush, green spaces across the continents that would later become suitable habitats for land animals.
But now, new research has found that plants actually spread across the Earth 100 million years earlier, calling into question our knowledge of early Earth and the evolution of its biosphere.
Previous theories of plants first appearing on land came from studies of the oldest plant fossils, which dated back 420 million years.
However, researchers from the University of Bristol, Cardiff University, and the Natural History Museum used molecular clock dating methods to find that these fossils are not proof of the first on Earth.
“The fossil record is too sparse and incomplete to be a reliable guide to date the origin of land plants,” said Mark Puttick, a lead author of the study. “Instead of relying on the fossil record alone, we used a ‘molecular clock’ approach to compare differences in the make-up of genes of living species – these relative genetic differences were then converted into ages by using the fossil ages as a loose framework.”
Their findings were published in the journal Proceedings of the National Academy of Sciences.
Molecular clock methodology combines evidence on the genetic differences between both fossils and living species.
By examining the genetic data, the researchers were able to pinpoint an evolutionary timeline based on shared ancestors of fossils and living plant species today.
The researchers also examined atmospheric data to understand how early plant species shaped the Earth’s climate.
“Previous attempts to model these changes in the atmosphere have accepted the plant fossil record at face value – our research shows that these fossil ages underestimate the origins of land plants, and so these models need to be revised,” said Jennifer Morris, a lead co-author of the study.
Taking all these factors into consideration, the more accurate estimate shows that plants likely first colonized Earth 520 million years ago.
The research team made sure to test if different relationships between early land plants changed their origin timeline.
“We used different assumptions on the relationships between land plants and found this did not impact the age of the earliest land plants,” said Philip Donoghue and Harald Schneider, leaders of the research.
“Any future attempts to model atmospheric changes in deep-time must incorporate the full range of uncertainties we have used here.”
The results show that land plants likely formed on Earth much earlier than previously thought and sheds new insight into Earth’s early climate and biosphere.
Biodiversity loss can cause snowball extinction effect
Biodiversity loss is occurring faster than ever due to habitat loss caused by human activity and anthropogenic climate change. In fact, one 2016 study found that biodiversity loss is reaching unsafe levels.
Biodiversity loss can cause a snowball effect where the extinction of one species leads to the extinction of others. This effect is known as an extinction cascade because one extinction can cause more due to the gap in the ecosystem.
Now, new research has found that extinction cascades have a higher likelihood of happening in areas where the loss of a species can’t be substituted by any others at the same level of the food chain. In other words, no other species can fill the empty slot.
Researchers from the University of Exeter conducted the study, and their findings show that even if one species loss doesn’t snowball into a cascade effect, the loss of biodiversity creates a higher risk of extinctions.
“Interactions between species are important for ecosystem (a community of interacting species) stability,” said Dirk Sanders, an author of the study. “And because species are interconnected through multiple interactions, an impact on one species can affect others as well.”
This new study shows that loss of one species through human activities isn’t the only concern, but that one species loss could lead to more.
The researchers wanted to see if more complex food webs provided a buffer against extinction cascades.
“It has been predicted that more complex food webs will be less vulnerable to extinction cascades because there is a greater chance that other species can step in and buffer against the effects of species loss,” said Sanders. “In our experiment, we used communities of plants and insects to test this prediction.”
For the study, the researchers removed a species of wasp from their plant and insect ecosystem.
The loss of the wasps led to other species’ loss. The results showed that smaller webs were more acutely affected compared to complex food webs.
“Our results demonstrate that biodiversity loss can increase the vulnerability of ecosystems to secondary extinctions which, when they occur, can then lead to further simplification causing run-away extinction cascades,” said Sanders.
It’s a dangerous snowball effect that could wreak havoc on crucial ecosystems. This study shows the necessity of preserving biodiversity and trying to reduce the instances of species loss during a time when extinction is peaking higher than ever.
Farming with crushed rocks can help soak up carbon
The soil around volcanoes is some of the most fertile on Earth. When ash and sediment erupt from a volcano in a pyroclastic flow, these deposits can quickly break down in the surrounding soil and form mineral-rich dirt that is ideal for crops.
Now, new research has found that it’s possible to mimic this mineral-rich effect and also soak up carbon dioxide by adding crushed rocks to farmland. As the rocks dissolve in the soil, they release vital nutrients and create ideal conditions for agriculture.
The study was conducted by researchers from the University of Sheffield along with an international team of scientists and is the first of its kind to suggest mineral rich soils as a solution to help mitigate carbon emissions.
Their findings were published in the journal Nature Plants.
“Human societies have long known that volcanic plains are fertile, ideal places for growing crops without adverse human health effects, but until now there has been little consideration for how adding further rocks to soils might capture carbon,” said David Beerling, the lead author of the study.
The key, according to the study, lies in adding fast-acting silicate rock deposits, such as crushed basalt, to farmlands and soil. The minerals would add a barrier against pests and disease and aid in carbon capture.
Some added benefits of using this method, which is called enhanced rock weathering, are that it wouldn’t take away possible croplands or put a strain on water resources.
The silicate rocks could be added to any soils, but the study suggests that arable lands capable of being plowed for crops is the optimal place to start.
Several arable farms already put crushed limestone in the soil, so the materials and equipment needed to try enhanced rock weathering are already in place.
Enhanced rock weathering could help ensure future global food security and provide a new outlet for soaking up carbon.
“The magnitude of future climate change could be moderated by immediately reducing the amount of CO2 entering the atmosphere as a result of energy generation,” said Beerling. “Adopting strategies like this new research that actively remove CO2 from it can have a massive impact and be adapted very quickly.”
The researchers are hopeful their methods could be used to create nutrient soil that helps in mitigating the effects of climate change.
“Strategies for taking CO2 out of the atmosphere are now on the research agenda, and we need realistic assessment of these strategies, what they might be able to deliver, and what the challenges are,” said James Hansen from the Earth Institute at Columbia University, a co-author of the study.
Plastic found in 73 percent of northwest Atlantic deep sea fish
A troubling new study has found plastic particles in 73 percent of deep sea fish in the northwest Atlantic Ocean.
The study was performed by researchers at the National University of Ireland in Galway and examined 233 fish up to a depth of 1,970 feet below the surface.
The researchers noted that a large proportion of the fish studied were smaller fish found between 640 and 3,300 feet deep. When these fish are eaten by larger fish, such as mackerel or tuna, the plastic particles are passed along.
Plastic particles that seep into the environment, also known as microplastics, can be very harmful to fish and cause severe internal damage, inflammation, and impact their ability to eat. But the trouble doesn’t stop there. Microplastics can then be passed along to humans who consume the fish.
“Deep-water fish migrate to the surface at night to feed on microscopic plankton and this is likely when they are exposed to the microplastics,” explained Alina Wieczorek of the National University of Ireland in Galway and lead author of the study.
“Microplastic pollution has been in the news recently, with several governments planning a ban on microbeads used in cosmetics and detergents. The high ingestion rate of microplastics by mesopelagic fish we observed has important consequences for the health of marine ecosystems and bio-geochemical cycling in general.”
The widespread impact of plastic pollution continues to be felt around the world. As we reported, another recent study found that whales and filter feeders ingest 171 plastic items per day.
Last month, British Prime Minister Theresa May announced an ambitious plan to make the UK free of plastic waste over the next 25 years.
What remains clear is that the issue of plastic pollution will only continue to worsen until an organized and concerted effort is made to eradicate humans’ plastic dependency.
“We recorded one of the highest frequencies of microplastics among fish species globally,” Wieczorek said.