Million-year-old Arctic sedimentary record sheds light on climate mystery, researchers find

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Lake El´gygytgyn. Credit: UMass Amherst

New research, led by the University of Massachusetts Amherst and published recently in the journal Climate of the Past, is the first to provide a continuous look at a shift in climate, called the Mid-Pleistocene Transition, that has puzzled scientists. Kurt Lindberg, the paper’s first author and currently a graduate student at the University at Buffalo, was only an undergraduate when he completed the research as part of a team that included world-renowned climate scientists at UMass Amherst.

Somewhere around 1.2 million years ago, a dramatic shift in the Earth’s climate, known as the Mid-Pleistocene Transition, or MPT, happened. Previously, ice ages had occurred, with relative regularity, every 40,000 years or so. But then, in a comparatively short window of geological time, the time between ice ages more than doubled, to every 100,000 years. “It’s a real puzzle,” says Isla Castañeda, professor of geosciences at UMass Amherst and one of the paper’s co-authors. “No one really knows why this shift occurred.”

One of the big barriers to understanding the MPT is that very little data exists. The oldest Arctic ice cores only go back approximately 125,000 years. And older sedimentary cores are almost nonexistent, because as ice ages have come and gone, the advancing and retreating ice sheets have acted like enormous bulldozers, scraping much of the exposed land down to bedrock.

However, there is one place in the world, in far northeastern Russia, that is both above the Arctic Circle and which has never been covered by glaciers: Lake El’gygytgyn. This is where the world-renowned polar scientist, Julie Brigham-Grette, professor of geosciences at UMass Amherst and one of the paper’s co-authors, comes in.

In 2009, Brigham-Grette led an international team of scientists to Lake El’gygytgyn, where they drilled a 685.5 meter sediment core, representing approximately the last 3.6 million years of Earth’s history. Lindberg and his co-authors used the portion of this sedimentary core that spanned the MPT and looked for specific biomarkers that could help them ascertain temperature and vegetation. With this information, they were able to reconstruct, for the first time, climactic conditions in the Arctic during the MPT.

While the team did not solve the mystery of the MPT, they did make a few surprising discoveries. For example, an , or era when ice was in retreat, known as MIS 31 is widely recognized as having been abnormally warm—and yet the records at Lake El’gygytgyn show only moderate warmth. Instead, three other , MIS 21, 27 and 29 were as warm or warmer. Finally, the team’s research shows a long-term drying trend throughout the MPT.

“This couldn’t have been done without Lindberg’s enthusiasm,” says Castañeda. “I’ve always had lots of undergrads in my lab, and I love working with them. Kurt took off with this project, and did a wonderful job.”



More information:
Kurt R. Lindberg et al, Biomarker Proxy Records of Arctic Climate Change During the Mid-Pleistocene Transition from Lake El’gygytgyn (Far East Russia), Climate of the Past (2021). DOI: 10.5194/cp-2021-66

Citation:
Million-year-old Arctic sedimentary record sheds light on climate mystery, researchers find (2022, March 30)
retrieved 31 March 2022
from https://phys.org/news/2022-03-million-year-old-arctic-sedimentary-climate-mystery.html

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Improving predictions of ‘flesh-eating’ bacteria in Ala Wai Canal, Hawai’i

Field team casting off at the Ala Wai Harbor. Pictured: Kyle Conner, Zoe Glenn, Olivia Hughes, Ashley Hiʻilani Sanchez, Jessica Bullington, and Solomon Chen. Credit: Brian Glazer/ UH SOEST.

Recently published research led by University of Hawai’i (UH) at Mānoa scientists highlights the potential for using oceanographic sensors to make accurate predictions of Vibrio vulnificus, an infectious bacterium, in the Ala Wai Canal in Waikiki, Hawai’i. By assessing rainfall, water temperature, dissolved nutrients and organic matter the team now has the ability to forecast potential spikes in levels of the bacteria. 

V. vulnificus, a “flesh-eating” bacterium, lives naturally in the water of the Ala Wai Canal, but infections are rare. V. vulnificus has been relatively understudied in tropical ecosystems and further, the implications of climate change for this and other coastal human pathogens are generally unknown.

The research team collaborated with the UH Strategic Monitoring and Resilience Training in the Ala Wai Watershed (SMART Ala Wai Program) where at least 20 and six graduate students from the UH Mānoa School of Ocean and Earth Science and Technology participated in sample collection from the canal and processing at the Daniel K. Inouye Center for Microbial Oceanography: Research and Education.

Consistent with another recently published UH study, rainfall was found to be critically important for both elevating the pathogen’s abundance in the canal and transporting V. vulnificus to the adjacent Ala Wai Boat Harbor.

“We also found that measuring the amount of a particular kind of dissolved in the water significantly improved our model’s accuracy in predicting V. vulnificus abundance,” said lead author Jessica Bullington, who was pursuing her Master’s degree in the SOEST Department of Oceanography at the time of this work.

Lab team setting up to process samples at C-MORE. Pictured: Rayna McClintock, Han Quach, Brianna Ornelas, and Abigail Golder. Credit: Jessica Bullington/ UH SOEST

Ocean sensors provide necessary data

Water quality monitoring that involves collecting samples and analyzing them in a laboratory is expensive and often limited to select locations. Fortunately, there are oceanographic sensors that continuously monitor at the mouth of the Ala Wai Canal.

“What is really exciting about our research findings is the ability to use real-time and forecast data from the Pacific Islands Ocean Observing System (PacIOOS)—which includes water temperature, salinity, currents, and dissolved organic matter—to predict V. vulnificus abundance in the canal and harbor now and three days into the future,” said Bullington, who is now a doctoral student at Stanford University. “The next steps are to make these predictions accessible and communicate the risk of infection, both for short-term use and adaptation to the impacts of climate change.”

Warmer waters as climate changes

Because V. vulnificus abundance was higher when temperatures were warmer, and climate change is predicted to increase in the Ala Wai Canal, the researchers anticipate V. vulnifucus is likely to increase substantially in the canal in the coming decades.

By combining climate change projections of rainfall and air temperature with their computer model of bacteria dynamics, the team found that average V. vulnificus abundance in the may increase twice or three times current levels by the end of the century. Armed with this information, communities can make decisions on how to adapt to the changing conditions.

“Ultimately, we wanted to generate something that would be useful for people,” said Bullington. “This project is a great example of one of the many ways in which our departmental expertise can be of service for our local community and coastal management.”



More information:
Jessica A. Bullington et al, Refining real-time predictions of Vibrio vulnificus concentrations in a tropical urban estuary by incorporating dissolved organic matter dynamics, Science of The Total Environment (2022). DOI: 10.1016/j.scitotenv.2022.154075

Citation:
Improving predictions of ‘flesh-eating’ bacteria in Ala Wai Canal, Hawai’i (2022, March 30)
retrieved 31 March 2022
from https://phys.org/news/2022-03-flesh-eating-bacteria-ala-wai-canal.html

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New research highlights ‘significant gap’ in evidence about effectiveness of relationship education programs

Credit: CC0 Public Domain

Educators should have not have “high”‘ confidence in the quality of existing relationship education programs, because there is a lack of robust evaluation, experts have warned.

The findings from a new systematic review of relationship education programs provide evidence there is a “significant gap” in high-quality research into the outcomes of such programs. This is despite links between healthy relationships and good mental health and well-being, and the recent formalization of a larger role for relationship education in statutory guidance in England.

Researchers reviewed 20 relationship programs. All but one were developed in the US and 11 had been evaluated. Only three had followed participants for a year or longer and many programs and evaluations did not appear to be co-developed or designed with . Many evaluations had examined attitudes towards marriage, divorce or collaboration, with negative attitudes to divorce and cohabitation framed as . This may reflect policy in some US states to reinforce traditional attitudes.

Evaluations that had taken place were not high quality, with a lack of randomization, unbalanced samples and high attrition rates over time.

This “Beacon: Healthy Relationship” study was carried out by Simon Benham-Clarke, Georgina Roberts and Tamsin Newlove-Delgado from the University of Exeter and Astrid Janssens from the University of Southern Denmark and Odense University Hospital. It builds on evidence from the Shackleton Relationships Project, which showed an appetite among young people for more education at school (which they help to develop) about how to build positive relationships and handle “normal” relationship difficulties.

Simon Benham-Clarke said, “Because of a lack of good quality evaluation we were not able to conclude that any of the programs have a strong evidence base in terms of their impact on relationships skills or healthy relationship outcomes, particularly over the longer term.

“There needs to be more robust trials of relationships education programs, with their impact to be followed up over a long-term period. There should be a set of core measures to assess programs which connect directly to the desired outcomes and priorities for young people.”

The study, in the journal Pastoral Care in Education, says to improve relationship outcomes for young people it is critical that they are fully engaged in the development of new programs and the evaluation of such programs. However, the team found no evidence of young people’s involvement in program or evaluation development.

Dr. Newlove-Delgado explained, “We worked with a great group of young people on this research project. Young people want their voices heard and want to contribute to what they learn about relationships in schools. Both young people and relationship experts see relationship as having an important role in promoting and well-being, particularly through learning to cope with relationship breakdowns. They also want to learn skills which could help them maintain happy and over the longer term.”

The review recommends that future programs are co-created with young people, teachers and experts, and integrated into a -informed curriculum and wider prevention programs in schools and communities. Programs should be evaluated over the longer term and assessed for feasibility and acceptability in and community settings.



More information:
Simon Benham-Clarke et al, Healthy relationship education programmes for young people: systematic review of outcomes, Pastoral Care in Education (2022). DOI: 10.1080/02643944.2022.2054024

Citation:
New research highlights ‘significant gap’ in evidence about effectiveness of relationship education programs (2022, March 30)
retrieved 31 March 2022
from https://phys.org/news/2022-03-highlights-significant-gap-evidence-effectiveness.html

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Sea sponges need oxygen, as fish and people do

Processed wool sponge. Credit: Nicola Smith

The inconspicuous sea sponges are Earth’s oldest multicellular animals and have filtered the oceans for nearly 900 million years, long before the first plants appeared on land. New research appearing in the journal Fishery Bulletin, published by the National Oceanic and Atmospheric Administration, indicates that their growth depends on their oxygen supply in a manner similar to more complex animals such as fishes.

Researchers from the University of British Columbia and Florida International University explain that a “dimensional tension” is at play as sponges grow because they are forced to rely on the two-dimensional cross-section of their inhalant pores to supply their tridimensional growing bodies with dissolved in water.

By analyzing data from new and previous studies on sponges, and estimating their growth parameters, the researchers suggest that such respiratory stress in the central portion of spherical sponges, such as those that are commercially harvested, limits their maximum size. Past this size, sponges change from near-spherical to vase-shaped forms. The central, oxygen-poor part of near-spherical sponges is, however, rich in anaerobic microbes—those that do not require molecular oxygen to survive.

“This means that sponges have evolved in a way that allows them to nurture complex microbial communities within themselves to deal with the geometric constraints imposed on their physiology,” said Dr. Daniel Pauly, lead author of the study and principal investigator of the Sea Around Us initiative at UBC’s Institute for the Oceans and Fisheries.

“These are similar to the human gut microbiome and can be equivalent to 40% of the sponge wet body weight. High densities of microbes confer multiple beneficial functions for the sponge, such as metabolic regulation,” Dr. Pauly said.

The UBC researcher is the person behind the Gill Oxygen Limitation Theory, which explains the links between growth and respiration in fish and other water-breathing animals.

“Sponges originated over 800 million years ago in the Pre-Cambrian. At that time, atmospheric oxygen levels were only about 50% of what they are today. Although global oxygen stores later increased with the evolution of multicellular plants, for 500 million years sponges evolved in a world depauperate of oxygen. In the absence of tissues or organs specialized for oxygen acquisition, sponge morphology was likely strongly constrained by physiological oxygen demand,” said Dr. Mark Butler, of Florida International University, a co-author of the study.

Wool sponge. Credit: Mark Butler

Understanding the growth and evolution of these ancient organisms is important because they serve important ecological functions in marine ecosystems, including in coral reefs.

Sponges are responsible for regulating the exchange of energy, mass, and nutrients between habitats through filtration and nutrient cycling; enhancing habitat complexity; altering sediment structures; contributing to underwater soundscapes and providing food for spongivorous species.

“Sponges are also important to fisheries,” said Dr. Nicola Smith, another co-author of the study and a researcher at UBC’s Institute for the Oceans and Fisheries. “In the Caribbean, the export of marine sponges began in the mid-1800s as they were used for personal hygiene, house and car cleaning, medical surgery, glazing pottery, and cleaning industrial machinery, among other uses. Today, international demand for commercially harvested sponges is driven primarily by the cosmetic, biomedical and aquarium trades.”

Data from the Food and Agriculture Organization of the United Nations show that nearly 40,000 tons of processed sponges were exported by two dozen countries from 1950 to 2019, corresponding to 1 million tons in live weight.

“When it comes to the number of countries exploiting sponge populations and their catches, the FAO numbers are likely underestimates,” Dr. Smith said. “Also, the effects of commercial fisheries on sponge communities are largely unknown, although in south Florida, management limitation of harvest to the use of artisanal techniques appears to have produced a sustainable fishery. In the past, however, many sponge fisheries have been so overexploited that they collapsed.”

Following this study, the researchers will join forces with other colleagues to perform a detailed reconstruction of the catches of commercial sponges around the world.



More information:
Daniel Pauly et al, Growth and related traits of the sheepswool sponge (Hippospongia lachne): practical and theoretical considerations, Fishery Bulletin (2022). DOI: 10.7755/FB.120.2.1 spo.nmfs.noaa.gov/sites/defaul … h-bull/1202pauly.pdf

Citation:
Sea sponges need oxygen, as fish and people do (2022, March 30)
retrieved 31 March 2022
from htt

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