It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Thursday, July 20, 2023
Shark shock – scientists discover filter-feeding basking sharks are warm-bodied like great whites
VIDEO: APPROXIMATELY 99.9% OF FISH AND SHARK SPECIES ARE “COLD-BLOODED”, MEANING THEIR BODY TISSUES GENERALLY MATCH THE TEMPERATURE OF THE WATER THEY SWIM IN – BUT RESEARCHERS HAVE JUST DISCOVERED THE MIGHTY BASKING SHARK IS A ONE-IN-A-THOUSAND EXCEPTION.view more
CREDIT: TRINITY COLLEGE DUBLIN
Approximately 99.9% of fish and shark species are “cold-blooded”, meaning their body tissues generally match the temperature of the water they swim in – but researchers have just discovered the mighty basking shark is a one-in-a-thousand exception. Instead, these sharks keep the core regions of their bodies warmer than the water like the most athletic swimmers in the sea such as great white sharks, mako sharks and tuna.
The latter examples are so-called “regional endotherms” and are all fast swimming, apex predators at the top of the food chain. Scientists have long reasoned that their ability to keep warm helped with this athletic predatory lifestyle, and that evolution had shaped their physiology to match their requirements.
However, an international team of researchers led by those from Trinity College Dublin, has now shown that gentle, plankton-feeding basking sharks are also regional endotherms despite having very different lifestyles to white sharks and tunas.
This surprising discovery has implications for conservation, as well as raising a plethora of ecological and evolutionary questions.
Haley Dolton, PhD Candidate in Trinity’s School of Natural Sciences, was lead author of the study that has just been published in international journal, Endangered Species Research. She said:
“The basking shark is a shining example of how little we know about shark species in general. That we still have lots to uncover about the second biggest fish in the world – such a huge, charismatic animal that most people would recognise it – just highlights the challenge facing researchers to gather what they can about species to aid in effective conservation strategies.
Basking sharks gained legal protection in Irish waters just last year, with the species having undergone significant population declines throughout the NE Atlantic in the last century. But they still face many challenges in the future.
Haley Doltonadded: “Regional endotherms are thought to use more energy, and possibly respond differently to ocean warming than other fish species. So lots more work will need to be done to work out how these new findings regarding an endangered species might change previous assumptions about their metabolism or potential distribution shifts during our climate crisis, which is something marine biologists are focusing on as our planet and its seas continue to warm.
“Hopefully this kind of research will continue the momentum needed to effectively protect these incredible animals in Irish waters and further afield.”
To make the discovery, the research team (including scientists from University of Pretoria, Marine Biological Association, Queen’s University Belfast, Zoological Society of London, University of Southampton, and Manx Basking Shark Watch) first undertook dissections of dead basking sharks that washed up in Ireland and the UK.
They found that the sharks have cruise-swimming muscles located deep inside their bodies as seen in white sharks and tunas; in most fish this “red” muscle is instead found toward the outside of the animals.
They also discovered basking sharks have strong muscular hearts that probably help generate high blood pressures and flows. Most fish species have relatively “spongy” hearts, whereas basking shark hearts are more typical of the regional endotherm species.
Next, the team designed a new low-impact tagging method to record body temperature of free-swimming basking sharks off the coast of Co Cork, Ireland. Researchers were able get close enough to 8 m basking sharks to safely deploy the tags, which recorded muscle temperature just under the skin for up to 12 hours before they automatically detached from the animals and were collected by the researchers.
These tags revealed that basking shark muscles are consistently elevated above water temperatures, and to almost exactly the same extent as their regionally-endothermic predatory cousins.
Nicholas Payne, Assistant Professor in Trinity’s School of Natural Sciences, was senior author of the study. He said:
“These results cast an interesting new light on our perception of form versus function in fishes because until now we thought regional endothermy was only found in apex predatory species living at high positions in the marine food web.
“Now we have found a species that grazes on tiny plankton but also shares those rather uncommon regional endotherm features, so we might have to adjust our assumptions about the advantages of such physiological innovations for these animals.
“It’s a bit like suddenly finding that cows have wings.”
IMAGE: AN ADULT MALE WITH DEEP TOOTH RAKE MARKSview more
CREDIT: DAVID ELLIFRIT / CENTER FOR WHALE RESEARC
Post-menopause female killer whales protect their sons – but not their daughters – from fights with other whales, new research shows.
Scientists studied “tooth rake marks” – the scarring left when one whale scrapes their teeth across the skin of another – and found males had fewer marks if their mother was present and had stopped breeding.
Only six species – humans and five species of toothed whales – are known to experience menopause, and scientists have long been puzzled about why this occurs.
The new study – by the universities of Exeter and York, and the Center for Whale Research – adds to growing evidence that post-menopause females boost the life chances of their offspring, especially males.
“These males had 35% fewer tooth marks than other males.
“For males whose mother was still breeding, we found no evidence that her presence reduced tooth rake injuries.
“We can’t say for sure why this changes after menopause, but one possibility is that ceasing breeding frees up time and energy for mothers to protect their sons.
“Tooth rake marks are indicators of physical social interactions in killer whales and are typically obtained through fighting or rough play.”
The study is part of long-term research on “southern resident” killer whales, which live off the Pacific coast of North America.
The body of evidence suggests that – instead of competing with their daughters to breed – female killer whales have evolved to pass on their genes by helping their children and grandchildren.
Commenting on why females focus efforts on their sons, Grimes said: “Males can breed with multiple females, so they have more potential to pass on their mother’s genes.
“Also, males breed with females outside their social group – so the burden of raising the calf falls on another pod.”
Southern resident killer whales feed on salmon and have no natural predators apart from humans, so tooth marks on their skin can only be inflicted by other killer whales.
This may happen within social groups, or when two pods meet.
Commenting on how mothers protect their sons, Professor Darren Croft, also from the University of Exeter, said: “We can’t say for sure.
“It’s possible that the older females use their experience to help their sons navigate social encounters with other whales.
“They will have previous experience of individuals in other pods and knowledge of their behaviour, and could therefore lead their sons away from potentially dangerous interactions.
“The mothers might also intervene when a fight looks likely.”
Professor Croft added: “The similarities with humans are intriguing.
“Just as in humans, it seems that older female whales play a vital role in their societies – using their knowledge and experience to provide benefits including finding food and resolving conflict.”
Professor Dan Franks, from the Department of Biology at the University of York, said: "Our findings offer captivating insights into the role of post-menopausal killer whale mothers.
“They perform protective behaviour, reducing the incidence of socially inflicted injuries on their sons.
“It's fascinating to see this post-menopausal mother-son relationship deepening our understanding of both the intricate social structures in killer whale societies and the evolution of menopause in species beyond humans."
The study was supported by the Natural Environment Research Council.
The paper, published in the journal Current Biology, is entitled: “Postreproductive female killer whales reduce socially inflicted injuries in their male offspring.”
An adult male with travelling with its post-reproductive mother
IMAGE: AN ADULT MALE ORCA WITH TOOTH RAKE MARKSview more
CREDIT: COPYRIGHT DAVID ELLIFRIT, CENTER FOR WHALE RESEARCH
Female killer whales live up to ninety years in the wild, and most live an average of twenty-two years after menopause. Scientists have long wondered why humans and some whale species spend a significant portion of their life not reproducing. Previous studies show that, even after having their last calf, killer whale mothers take care of their families by sharing the fish they catch. Now, in a study published on July 20 in the journal Current Biology, researchers note that these mothers can also provide social support to their sons by protecting them from being injured by other orcas.
“The motivation of this project was really to try and understand how these post-reproductive females are helping their offspring,” says first author Charli Grimes, an animal-behavior scientist at the University of Exeter. “Our results highlight a new pathway by which menopause is adaptive in killer whales.”
The research team studied southern resident orcas, a group of orcas that live off the Pacific Northwest coast. These killer whales live in matriarchal social units that consist of a mother, her offspring, and the offspring of her daughters. Although male orcas will outbreed with whales from other pods, both males and females stay in their unit of birth, with their mother, for life.
Using data from the Center for Whale Research’s annual photographic census of the orca population, the researchers looked for evidence of scarring on each catalogued whale’s skin. Killer whales have no natural predators other than humans, so a tooth mark that is able to puncture an orca’s skin was most likely inflicted by another orca.
The study found that, if a given male’s mother was still alive and no longer reproducing, that male would have fewer tooth marks than his motherless peers or his peers with a mother who was still reproducing.
“It was striking to see how directed the social support was,” says senior author Darren Croft (@DarrenPCroft), an animal-behavior scientist at the University of Exeter. “If you have a post-reproductive mother who’s not your mother within the social group, there’s no benefit. It’s not that these females are performing a general policing role. These post-reproductive mothers are targeting the support they are giving to their sons.”
The researchers still can’t say for certain what kinds of social conflicts are leading to tooth marks or how older females are protecting their sons against them. They do note that post-menopause females have the lowest incidence of tooth marks in the entire social unit, suggesting that they do not physically intervene in a conflict. If older orca females play a similar role to that of older women in human societies, they might be acting as mediators, preventing conflict from occurring in the first place. To explore this further, the researchers plan on completing an additional study by using drone footage to observe whale behavior from above.
“It’s possible that with age comes advanced social knowledge. Over time, they might have a better understanding of other social groups,” says Grimes. “Given these close mother-son associations, it could also be that she is present in a situation of conflict so she can signal to her sons to avoid the risky behavior they might be participating in.”
“We’ve got hypotheses, but we need to test them by seeing what’s happening under water when these different groups interact,” says Croft. “We’ve learned so much from this population, but we’ve still got so much to learn from them.”
This work was supported by the Natural Environment Research Council. The authors declare no conflicts of interest.
Current Biology (@CurrentBiology), published by Cell Press, is a bimonthly journal that features papers across all areas of biology. Current Biology strives to foster communication across fields of biology, both by publishing important findings of general interest and through highly accessible front matter for non-specialists. Visit:http://www.cell.com/current-biology. To receive Cell Press media alerts, contactpress@cell.com.
A post menopause female orca traveling with her adult son
IMAGE: THE STUDY WILL INCLUDE BOTH FIELD STUDIES AND COMPUTER MODELING AND WILL BE FOCUSED ON TWO SMALL STREAM BASINS THAT ARE HEAVILY INFLUENCED BY AGRICULTURE AS CASE STUDY WATERSHEDS. THE RESEARCHERS WILL MEASURE AND ANALYZE RIPARIAN BUFFER PERFORMANCE IN THE HEADWATERS OF MAHANTANGO CREEK IN DAUPHIN COUNTY AND IN THE HALFMOON CREEK WATERSHED IN CENTRE COUNTY.view more
CREDIT: TYLER GROH/PENN STATE.
UNIVERSITY PARK, Pa. — At a time when Pennsylvania is actively working to achieve water-quality improvements to meet the state’s obligations for cleaning up the Chesapeake Bay, a multidisciplinary Penn State research team is studying whether agricultural pollution-prevention devices called riparian buffers are working properly.
Riparian buffers — areas adjacent to streams or wetlands that contain a combination of trees, shrubs and grasses — are managed differently from the surrounding landscape to provide conservation benefits. In agricultural areas, buffers intercept sediment, nutrients, pesticides and chemicals of environmental concern in surface runoff and in shallow subsurface water flow to reduce the amounts that get into waterways.
The most recent Watershed Implementation Plan that Pennsylvania submitted to the U.S. Environmental Protection Agency includes 83,000 acres of new riparian buffers along streams on agricultural lands. The estimated cost to establish those buffers exceeds $20 million annually through 2025. Obviously, it would be helpful for state and federal officials to know how effective buffers really are, according to research team leader Heather Preisendanz, associate professor of agricultural and biological engineering.
Questions have emerged about existing buffers’ capabilities, she explained. In a recent survey of 52 buffers at long-term agricultural research sites, 27 were underperforming by as much as 78%, damaged by breaches called concentrated flow pathways. These torrents of varying intensity undermine buffers’ integrity by “short circuiting” them, essentially enabling surface runoff to enter streams untreated.
Such short-circuiting can render the potential pollution-mitigation properties of buffers ineffective in the most extreme cases.
“If we're going to put such a large portion of our eggs into the buffers basket, then we want to make sure that they are performing the way we need them to,” Preisendanz said. “Pennsylvania is relying on forested buffers to meet 49% of its phosphorus-reduction goals and 16% of its nitrogen-reduction goals. If buffers underperform, then Pennsylvania and other states that use them as an integral component of watershed management plans will struggle to achieve load-reduction goals. We definitely need to understand how to make buffers as effective as possible to meet these goals.”
Funded by a three-year, $750,000 grant from the U.S. Department of Agriculture’s National Institute of Food and Agriculture, Preisendanz and colleagues in the College of Agricultural Sciences will evaluate the role that concentrated flow pathways play in undermining the ability of riparian buffers to mitigate excess nutrients, sediments and pesticides. The researchers will also develop solutions for restoring and maintaining buffer integrity.
The study will include both field studies and computer modeling. The team selected two small stream basins that are heavily influenced by agriculture as case study watersheds. They will measure and analyze riparian buffer performance in the headwaters of Mahantango Creek in Dauphin County and in the Halfmoon Creek watershed in Centre County. Both streams are impaired due to agricultural sources of sediment.
Modeling will include new, innovative methods of measuring the volume, intensity and path of runoff using modern GIS tools and drone image mapping. The researchers will evaluate runoff for nutrient, sediment, pesticides and chemicals of environmental concern, determining the extent to which “hot spots” for nutrients and pesticides overlap with concentrated flow pathways drainage areas.
“This will allow the team to identify the most vulnerable locations in the watersheds and offer appropriate solutions for minimizing the impact of these ‘hot spots’ on water quality,” Preisendanz said.
Finally, the researchers plan to conduct farmer surveys to evaluate the willingness of farmers to adopt runoff-control technologies and develop a coupled water quality and socioeconomic model that can inform watershed-scale decision making regarding adoption of new riparian buffers.
Results of the field-based studies will be used to develop and validate computer-based toolkits that can predict the occurrence of concentrated flow pathways, Preisendanz pointed out. “Overall, the results of this project will provide the data and tools needed to restore and maintain buffer integrity,” she said.
Other team members include Patrick Drohan, professor of pedology; Cibin Raj, associate professor of agricultural and biological engineering;Katherine Zipp, associate professor of environmental and resource economics; DanielBrent, assistant professor in the Department of Agricultural Economics, Sociology, and Education; Tyler Groh, assistant research professor in ecosystem science and management and watershed management specialist for Penn State Extension; and Tamie Veith, agricultural engineer with USDA-Agricultural Research Service Pasture Systems and Watershed Management Research Unit.
Also, Henry Kibuye, a graduate student studying bioenewable systems, has been assigned to this research project. He was selected as a recipient of the Extension Support Assistantship by Penn State Extension.
This illustration shows the fate and transport of pesticide after application in an agroecosystem. It shows how concentrated flow pathways play a major role in contaminating streams.
CREDIT
Penn State
New catalyst could dramatically cut methane pollution from millions of engines
Researchers demonstrate a way to remove the potent greenhouse gas from the exhaust of engines that burn natural gas.
IMAGE: TODAY'S CATALYSTS FOR REMOVING UNBURNT METHANE FROM NATURAL GAS ENGINE EXHAUST ARE EITHER INEFFICIENT AT LOW, START-UP TEMPERATURES OR BREAK DOWN AT HIGHER OPERATING TEMPERATURES. A NEW SINGLE-ATOM CATALYST DEVELOPED BY SLAC NATIONAL ACCELERATOR LABORATORY AND WASHINGTON STATE UNIVERSITY SOLVES BOTH THESE PROBLEMS AND REMOVES 90% OF THE METHANE. THIS ILLUSTRATION DEPICTS INDIVIDUAL PALLADIUM ATOMS (WHITE) REMOVING METHANE (WHITE BUBBLES) AT THE SURFACE OF THE CATALYST.view more
CREDIT: CORTLAND JOHNSON/PACIFIC NORTHWEST NATIONAL LABORATORY
Individual palladium atoms attached to the surface of a catalyst can remove 90% of unburned methane from natural-gas engine exhaust at low temperatures, scientists reported today in the journal Nature Catalysis.
While more research needs to be done, they said, the advance in single atom catalysis has the potential to lower exhaust emissions of methane, one of the worst greenhouse gases, which traps heat at about 25 times the rate of carbon dioxide.
Researchers from the Department of Energy’s SLAC National Accelerator Laboratory and Washington State University showed that the catalyst removed methane from engine exhaust at both the lower temperatures where engines start up and the higher temperatures where they operate most efficiently, but where catalysts often break down.
“It’s almost a self-modulating process which miraculously overcomes the challenges that people have been fighting – low temperature inactivity and high temperature instability,” said Yong Wang, Regents Professor in WSU’s Gene and Linda Voiland School of Chemical Engineering and Bioengineering and one of four lead authors on the paper.
A growing source of methane pollution
Engines that run on natural gas power 30 million to 40 million vehicles worldwide and are popular in Europe and Asia. The natural gas industry also uses them to run compressors that pump gas to people’s homes. They are generally considered cleaner than gasoline or diesel engines, creating less carbon and particulate pollution.
However, when natural-gas engines start up, they emit unburnt, heat-trapping methane because their catalytic converters don’t work well at low temperatures. Today's catalysts for methane removal are either inefficient at lower exhaust temperatures or they severely degrade at higher temperatures.
“There’s a big drive towards using natural gas, but when you use it for combustion engines, there will always be unburnt natural gas from the exhaust, and you have to find a way to remove that. If not, you cause more severe global warming,” said co-author Frank Abild-Pedersen, a SLAC staff scientist and co-director of the lab’s SUNCAT Center for Interface Science and Catalysis, which is run jointly with Stanford University. “If you can remove 90% of the methane from the exhaust and keep the reaction stable, that’s tremendous.”
A catalyst with single atoms of the chemically active metal dispersed on a support also uses every atom of the expensive and precious metal, Wang added.
“If you can make them more reactive,” he said, “that’s the icing on the cake.”
Unexpected help from a fellow pollutant
In their work, the researchers showed that their catalyst made from single palladium atoms on a cerium oxide support efficiently removed methane from engine exhaust, even when the engine was just starting.
They also found that trace amounts of carbon monoxide that are always present in engine exhaust played a key role in dynamically forming active sites for the reaction at room temperature. The carbon monoxide helped the single atoms of palladium migrate to form two- or three-atom clusters that efficiently break apart the methane molecules at low temperatures.
Then, as the exhaust temperatures rose, the clusters broke up into single atoms and redispersed, so that the catalyst was thermally stable. This reversible process enabled the catalyst to work effectively and used every palladium atom the entire time the engine was running – including when it started cold.
“We were really able to find a way to keep the supported palladium catalyst stable and highly active and, because of the diverse expertise across the team, to understand why this was occurring,” said SLAC staff scientist Christopher Tassone.
The researchers are working to further advance the catalyst technology. They would like to better understand why palladium behaves in one way while other precious metals such as platinum act differently.
The research has a way to go before it will be put inside a car, but the researchers are collaborating with industry partners as well as with DOE’s Pacific Northwest National Laboratory to move the work closer to commercialization.
Along with Wang, Abild-Pedersen, and Tassone, Dong Jiang, senior research associate in WSU’s Voiland School, also led the work. The work was funded by the DOE Office of Science, and included research carried out at SLAC’s Stanford Synchrotron Radiation Lightsource (SSRL), Argonne National Laboratory’s Advanced Photon Source (APS) and the National Energy Research Scientific Computing Center (NERSC), which are all DOE Office of Science user facilities.
This article has been adapted from a press release written by Washington State University.
SLAC is a vibrant multiprogram laboratory that explores how the universe works at the biggest, smallest and fastest scales and invents powerful tools used by scientists around the globe. With research spanning particle physics, astrophysics and cosmology, materials, chemistry, bio- and energy sciences and scientific computing, we help solve real-world problems and advance the interests of the nation.
SLAC is operated by Stanford University for the U.S. Department of Energy’sOffice of Science. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time.
A catalyst using a single or just a few palladium atoms removed 90% of unburned methane from natural gas engine exhaust at low temperatures in a recent study. While more research needs to be done, the advance in single atom catalysis has the potential to lower exhaust emissions of methane, one of the worst greenhouse gases that traps heat at about 25 times the rate of carbon dioxide.
Reporting in the journal, Nature Catalysis, a research effort between Washington State University and SLAC National Accelerator Laboratory showed that the single-atom catalyst was able to remove methane from engine exhaust at lower temperatures, less than 350 degrees Celsius (662 degrees Fahrenheit), while maintaining reaction stability at higher temperatures.
“It’s almost a self-modulating process which miraculously overcomes the challenges that people have been fighting – low temperature inactivity and high temperature instability,” said Yong Wang, Regents Professor in WSU’s Gene and Linda Voiland School of Chemical Engineering and Bioengineering and a corresponding author on the paper.
Natural gas engines are used in about 30 million to 40 million vehicles worldwide and are popular in Europe and Asia. The gas industry also uses them to run compressors that pump natural gas to people’s homes. They are generally considered cleaner than gasoline or diesel engines, creating less carbon and particulate pollution.
However, when these natural gas-powered engines start up, they emit unburnt, heat-trapping methane because their catalytic converters don’t work well at low temperatures. The catalysts for methane removal are either inefficient at lower exhaust temperatures or they severely degrade at higher temperatures.
“There’s a big drive towards using natural gas, but when you use it for combustion engines, there will always be unburnt natural gas from the exhaust, and you have to find a way to remove that. If not, you cause more severe global warming,” said co-author Frank Abild-Pedersen, a staff scientist at SLAC National Accelerator Laboratory. “If you can remove 90% of the methane from the exhaust and keep the reaction stable, that’s tremendous.”
A single-atom catalyst with the active metals singly dispersed on a support also uses every atom of the expensive and precious metals, Wang added.
“If you can make them more reactive, that’s the icing on the cake,” he said.
In their work, the researchers were able to show that their catalyst made from single palladium atoms on a cerium oxide support efficiently removed methane from engine exhaust, even when the engine was just starting.
They found that trace amounts of carbon monoxide that are always present in engine exhaust played a key role in dynamically forming active sites for the reaction at room temperature. The carbon monoxide helped the single atoms of palladium migrate to form two- or three-atom clusters that efficiently break apart the methane molecules at low temperatures.
Then, as the exhaust temperatures rose, the sub-nanometer-sized clusters re-dispersed to single atoms again so that the catalyst was thermally stable. This reversible process enables the catalyst to work effectively and uses every palladium atom the entire time the engine was running – including when it started cold.
“We were really able to find a way to keep the supported palladium catalyst stable and highly active and because of the diverse expertise across the team, to understand why this was occurring,” said Christopher Tassone, a staff scientist at SLAC National Accelerator Laboratory and co-author on the paper.
The researchers are working to further advance the catalyst technology. They would like to better understand why palladium behaves in one way while other precious metals such as platinum act differently.
The research has a way to go before it will be put inside a car, but the researchers are collaborating with industry partners as well as with Pacific Northwest National Laboratory to someday move the work closer to commercialization.
In addition to Wang, Abild-Pedersen, and Tassone, Dong Jiang, senior research associate in the Voiland School, also led the work. The work was funded by the U.S. Department of Energy’s Office of Basic Energy Sciences.
