Friday, February 07, 2025

 

Tracking algae species interactions to help predict harmful algae blooms





Hiroshima University




Harmful algal blooms, sometimes called HABs, occur when algae grow out of control. Algae are photosynthetic organisms that mostly live in water and rely on the sunlight for energy. Because of climate change, the frequency and intensity of harmful algal blooms are increasing globally. Researchers at Hiroshima University have uncovered new insights into how algae species interact with each other and their environment in coastal waters.

The research was published in Marine Pollution Bulletin on 15 December. 

“This study aimed to understand how harmful algal species interact with other phytoplankton and environmental factors like temperature and salinity. This understanding is crucial because harmful algal blooms have been increasing in frequency and intensity in Chile, causing substantial damage to the aquaculture industry, particularly salmon farming, which is vital to Chile’s economy as the world’s second-largest salmon producer,” said So Fujiyoshi, an assistant professor at Hiroshima University’s The IDEC Institute in Hiroshima, Japan.

The study analyzed these algal-algal species interactions through a statistical tool called empirical dynamic modeling, which can map relationships within a system using long-term data. This study used phytoplankton monitoring data that had been collected for 28 years to find out if temperature, salinity, or other phytoplankton species had an impact on the growth of Pseudo-nitzschia, one of the most common algal species groups found in harmful algal blooms. This species group is known to produce a neurotoxin called domoic acid. It contaminates shellfish and fish and can cause a rare illness called amnesic shellfish poisoning (ASP) if eaten. The symptoms of ASP include vomiting, nausea, diarrhea, headache, confusion, short-term memory loss, seizures, and, in rare cases, death.

“We discovered that Pseudo-nitzschia has complex interactions with other algal species. Our findings also suggest that salinity might have a more significant influence than temperature, which was previously thought to be a key factor. This discovery could improve our ability to predict harmful algal blooms,” said Fujiyoshi. 

The researchers emphasized that the empirical dynamic modeling method is only the start to understanding the interactions between Pseudo-nitzschia groups and other algal species. The next step would be real-world ecological observation.

Looking ahead, the research team hope to use what they learned to create a biological prediction model for harmful algal blooms. “The next steps would include additional environmental parameters, particularly nutrient variation due to upwelling, investigating the specific mechanisms behind how different phytoplankton species influence Pseudo-nitzschia, and developing these findings into a practical prediction model that could help protect aquaculture industry,” said Fujiyoshi.

Other contributors include Ishara Uhanie Perera at Yamaguchi University; Daiki Kumakura and Shinji Nakaoka at Hokkaido University; Carolina Medel, Oscar Espinoza-González, and Leonardo Guzmán at Instituto de Fomento Pesquero; Kyoko Yarimizu, Fumito Maruyama, Milko A. Jorquera, and Hansoo Lee at Hiroshima University; Felipe Tucca and Alexander Jaramillo-Torres at Instituto Tecnológico del Salmón; Yukako Tohsato at Ritsumeikan University; and Jacquelinne J. Acuña at Universidad de la Frontera. 

Science and Technology Research Partnership for Sustainable Development – Monitoring Algae in Chile, JSPS KAKENHI Fostering Joint International Research, and the JSPS Bilateral Program supported this research.

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About Hiroshima University

Since its foundation in 1949, Hiroshima University has striven to become one of the most prominent and comprehensive universities in Japan for the promotion and development of scholarship and education. Consisting of 12 schools for undergraduate level and 4 graduate schools, ranging from natural sciences to humanities and social sciences, the university has grown into one of the most distinguished comprehensive research universities in Japan. English website: https://www.hiroshima-u.ac.jp/en

 

Brain waves measure the effect of anti-alcohol campaigns



To evaluate the effectiveness of public video campaigns against risky alcohol consumption, psychologists from the Konstanz Cluster of Excellence "Collective Behaviour" use portable EEGs to examine the synchronization of brain activity in groups of viewers




University of Konstanz




Health campaigns, such as those against drug abuse or those promoting infection prevention measures during the coronavirus pandemic, are key public health tools and help protect the population. A recent campaign of the World Health Organization (WHO), for example, was launched in October 2024 under the motto "Redefine Alcohol". This call to action encourages people in Europe to reflect on the health effects of alcohol consumption, which, according to the WHO is currently directly responsible for one in eleven deaths in the European region.

However, not all health campaigns achieve the desired effect. Having an objective measure of the effectiveness of health-related messages at the campaign development stage would thus be extremely valuable. To this end, psychologists from the Konstanz Cluster of Excellence "Collective Behaviour" led by Harald Schupp and Britta Renner are conducting studies measuring the brain activity of viewers who watch real video health messages against risky alcohol consumption.

In laboratory experiments using advanced imaging techniques such as functional magnetic resonance imaging (fMRI) or electroencephalography (EEG), the researchers have previously demonstrated that particularly strong messages lead to an increased synchronization of the viewers' brain activity. This means that, when watching the video, the participants' brain activity changes in a similar way – particularly in regions of the brain associated with higher-order processes such as attention, emotions and personal relevance.

From the lab to real-world application
The Konstanz researchers used simpler, portable EEGs for the first time in a recent study. They measured the brain waves of the viewers in a standard seminar room – i.e. outside an elaborately shielded laboratory – and of a whole group of participants at the same time. They demonstrated that the synchronization of brain waves while watching particularly strong video messages against risky alcohol consumption can also be measured under these real-world conditions and with the simplified, more cost-effective technical setup.

"This is an important step toward making the method more practical for public health applications. In the future, EEG studies in small 'neural' focus groups conducted outside university laboratories could contribute to the evidence-based development and selection of campaign materials, ensuring greater effectiveness of health campaigns," says Schupp.

Read more about the synchronization of brain waves in humans and the advantages of using neural measures in psychology over classical surveys in our Science Backstage series: https://www.campus.uni-konstanz.de/en/science-backstage-1/measuring-brain-waves-to-assess-the-effectiveness-of-health-campaigns

Key facts:

  • Original publication: MA Imhof, K.-P. Flösch, R. Schmälzle, B. Renner & H.T. Schupp (2024) Portable EEG in groups shows increased brain coupling to strong health messages. Social Cognitive and Affective Neuroscience; doi: 10.1093/scan/nsae087
  • Researchers from the Konstanz Cluster of Excellence "Collective Behaviour" investigate the effectiveness of video health messages against risky alcohol consumption using synchronous EEG measurements in small groups.
  • Effective video messages cause the brain activity of viewers to synchronize more strongly than less effective messages.
  • Harald Schupp is a professor of general and biological psychology at the University of Konstanz. As part of the Cluster of Excellence "Collective Behaviour", he is project leader in the areas of brain synchronization and decision-making as well as nutrition and communal eating.
  • Britta Renner is a professor of psychological assessment and health psychology at the University of Konstanz. She is co-speaker of the Cluster of Excellence "Collective Behaviour" and leads the research project "Collective Appetite".
  • Funding: German Research Foundation (EXC2117-422037984 and FOR 2374) and Messmer Foundation

Note to editors:
You can download a photo here:

Link: https://www.uni-konstanz.de/fileadmin/pi/fileserver/2025_extra/hirnstroeme_zeigen.jpg
Caption: Wireless EEG as used in the study. Here, a student at the University of Konstanz is trying out a standard EEG experiment (oddball) as part of a course.
Copyright: Karl-Philipp Maria Flösch

 

Twenty years on, biodiversity struggles to take root in restored wetlands



While the restoration of natural areas is high on political agendas, a comprehensive new study from the University of Copenhagen shows that – after more than two decades – biodiversity growth has stalled in restored Danish wetlands.



University of Copenhagen - Faculty of Science





While the restoration of natural areas is high on political agendas, a comprehensive new study from the University of Copenhagen shows that – after more than two decades – biodiversity growth has stalled in restored Danish wetlands. The results also suggest that time alone will not heal things because the areas are too small and dry, and nitrogen inputs from agriculture continue. According to the researchers, we need to learn from the past.


The benefits are clear: natural areas with high biodiversity absorb CO2 and can help struggling marine environments by reducing nitrogen emissions.

The establishment of wetlands ranks high among the green priorities of politicians in Denmark and many other countries. And with the new Green Tripartite Agreement between the government, industry, agriculture and environmental groups, Denmark plans to invest significantly in restoring natural areas in coming years, with the creation of new wetlands being a key focus.

However, new research from the University of Copenhagen’s Department of Biology emphasizes that these initiatives must be executed with careful consideration. The study, which is the first detailed investigation of biodiversity in restored wetlands in Denmark, describes the restoration of Danish wetlands as a "modest success." Despite decades of restoration efforts, biodiversity has stalled far from the goal line.

"Our study shows that species richness is significantly lower in restored wetlands than in original, natural wetlands. Furthermore, these areas are dominated by a few competitive species, while rarer and more vulnerable plants and mosses fail to establish themselves. In fact around one third of species found in near natural wetlands are missing, and it's all the rare species that are missing," explains Marta Baumane from the University of Copenhagen’s Department of Biology.

Few to no moss species were to be found after the restorations, and the species-rich genus “Carex”, typical of natural wetlands, were also underrepresented in restored wetlands. Researchers found only five common species of Carex in restored areas, compared to ten different species – several rare - in the near natural wetlands.

Baumane is the lead author of the study, now published in the scientific journal Journal of Applied Ecology. The researchers examined plant biodiversity using available data on wetlands across the Denmark and their own fieldwork at 72 different sites in three river valleys: Omme, Odense, and Tryggevælde. All of the wetlands studied were reestablished after 2000.

Time will not heal it

The results also make it clear that allowing for more time is not the solution to struggling biodiversity, as long as the underlying causes remain unchanged.

"If we waited another 20 years and returned, it is doubtful that we would see any significant improvements. Using the registry data, we can look back and find records showing that these areas have stagnated for the past 10 years. We must assume that this is due to a number of underlying factors that have yet to change. High concentrations of nitrogen remain in the soil and though the streams have been meandered again, they are often still in deep river channels, so the wetlands along them are too dry," says Marta Baumane.

In part, nitrogen residue comes from the land’s previous use for high-input farming, but it also continues to flow in from neighbouring areas with active farming.

At the same time, the research reports that many areas are too small and affected by incomplete watercourse restorations. These areas still show signs of dredged rivers and streams, as well as artificial drainage systems, which continue to dry out the land and, according to the researchers, prevent a natural ecosystem from developing in restored wetlands.

Grazers, meandered streams and an end to slurry drainage mark the way forward

Recognizing the problems should be the first step toward solving them if you ask the researchers. Based on their new research, Baumane and her colleagues highlight several concrete measures that could improve biodiversity in both older and more recently restored wetlands.

One of the key recommendations is the use of grazing animals. The study shows that grazed restored wetlands have significantly more plant species richness compared to areas that have been left unmanaged. Indeed, grazers create a more diverse landscape, with favourable conditions for a wider range of species.

"In particular, grazing reduces the overgrowth of tall grasses, which makes space for low-growing plant species and mosses that would otherwise be outcompeted," explains Marta Baumane.

At the same time, the researchers recommend that efforts be made to reduce the amount of nutrient-laden drainage water discharged from surrounding fields and ensure full restoration of watercourses so that the areas have the right conditions to become true wetlands.

Natural grazing, water conditions and less nutrients are easier to achieve in larger contiguous areas than in small isolated areas surrounded by agriculture. The researchers' recommendation to create larger areas also harmonizes with a final recommendation for future projects, namely that they are placed near existing natural areas with high biodiversity, from which plants and other organisms can spread to the new wetlands.

A failure to prioritize biodiversity

According to the researchers, the projects included in the study reflect a political approach to wetland restoration where the primary goal has been to reduce nutrient inputs into waterways so as to improve freshwater and marine environments. Essentially becoming open air waste water treatment plants. They point out that biodiversity is frequently mentioned in project descriptions, but without a clearly defined objective.

“If we continue to treat the country's natural areas one-sidedly as a technical solution to our nutrient and CO2 emissions, it will continue to cost us biodiversity,” emphasizes Marta Baumane, who is supported by co-author Professor Hans Henrik Bruun from the Department of Biology.

"To avoid repeating the same mistakes in new wetland areas, biodiversity should be prioritized in future projects, for example in connection with the Green Tripartite. If Denmark is to achieve its biodiversity goals, it requires a much more ambitious effort," he says.

 

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Facts: Moss is a strong indicator

Few - often no - moss species were found in the new wetlands studied. Research shows that the diversity of mosses is high in semi-natural areas, while dense grass vegetation in restored wetlands leaves no room for them. Mosses can therefore be important indicators of biodiversity in wetlands. The researchers suggest that mosses can be used to assess whether restoration projects are on the right track.


Facts: No natural wetlands in Denmark, only near-natural

Denmark is so extensively cultivated that even the wetlands that the researchers used as a reference, i.e. a natural basis for comparison, are also highly influenced by humans and could not be described as fully natural.

Even though these areas have not been cultivated, they are so small and isolated, surrounded by agriculture and without natural watercourses etc. that an actual natural state is not present. Instead, researchers coined the term “near-natural”.


Facts: About the Study

• The study aims to assess the restoration of wetlands.

  • More specifically, it examines how the area's fertilization history, stream restoration, grazing, and species pool in the surroundings influence the achieved plant diversity compared to near-natural wetlands.

• The study was conducted on two spatial scales: landscape and local site.

  • At the landscape level, monitoring data from 48 restored wetlands across Denmark were used (including data on grazing density, water conditions, soil type, and other variables).
  • At the local site level, researchers compared vegetation, soil moisture, and nutrient levels in wetlands in three river valleys: Omme, Odense, and Tryggevælde. In each valley, four types of wetlands were studied: restored wetland with grazing [RG], restored ungrazed [RU], near-natural grazed [NG], and near-natural ungrazed [NU].

 

Behind the research

The following researchers where part of the research project - all from the Department of Biology, University of Copenhagen:

Marta Baumane

Lars Baastrup-Spohr

Kaj Sand-Jensen

Irina Goldberg

Kenneth Thorø Martinsen

Hans Henrik Bruun

 

UCF researchers advance knowledge about juvenile sea turtle’s early life stage, informing conservation efforts


These findings challenge existing hypotheses and provide important data for assessing risks from human activity and informing conservation efforts



University of Central Florida

Loggerhead Turtle 

image: 

One of five wild-caught juvenile loggerhead sea turtles from the Gulf of Mexico tracked in this study, before tagging. (Photo courtesy of Kate Mansfield)

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Credit: Photo courtesy of Kate Mansfield





Biology researchers from the College of Sciences’ UCF Marine Turtle Research Group studied the dispersal movements of four juvenile sea turtle species, revealing that they may be active swimmers, rather than passive drifters, during their early life stage known as the "lost years." These findings challenge existing hypotheses and provide important data for assessing risks from human activity and informing conservation efforts.

The study, funded largely in part by Florida RESTORE Act Centers of Excellence Program, was published this week in the journal Proceedings of the Royal Society B, representing the largest satellite tracking dataset of wild-caught juvenile sea turtle behavior from the Gulf of Mexico during this life stage, spanning from 2011 to 2022.

“One of the main findings is where these sea turtles are and where they go in this life stage because we haven’t known much about it,” says Katrina Phillips ’22PhD, who led the study alongside Nathan Putman and Kate Mansfield. Phillips says understanding these movement patterns among juvenile sea turtles will help guide conservation efforts to protect critical habitats for these species.

After hatching, sea turtles are known to leave their nests on land and enter the ocean where they spend their early years. This shift from terrestrial to oceanic habitat marks a critical transition in their life cycle to a life stage that has been understudied.

According to Mansfield, co-author of the study, professor of biology at UCF, and director of the UCF Marine Turtle Research Group, we are still learning about this life stage and it’s more complex than assumed.

“We don't know what they're eating, about their health, if and when they associate with floating algae called sargassum, which provides some protection,” Mansfield says.

The team of researchers tagged 131 juvenile sea turtles — 94 green turtles, 28 Kemp’s ridleys, five loggerheads, and four hawksbills — and tracked their movements using satellite-equipped, solar-powered platform transmitter terminals. These movements were compared with those of oceanographic surface drifters, floating objects used to study how sea turtle movements are influenced by ocean currents.

Researchers believe juvenile sea turtles swim offshore as an adaptive behavior to avoid predators such as birds, sharks and other fish, which are more abundant near the shoreline. Their small size makes them particularly vulnerable, so offshore waters can provide a safer refuge.

“One of the longstanding assumptions, is that juvenile sea turtles stay far offshore. Researchers call this the ‘oceanic life stage,’ which means off the continental shelf in waters deeper than 200 meters,” Phillips says. “However, what we found was that the turtles in this life stage are crossing over the continental shelf into neritic zones a lot more than we expected.”

A continental shelf is the gently sloping, shallow underwater area that extends between the shoreline and the continental slope, where the seabed drops steeply into the deep ocean at the shelf break. This shelf includes the neritic zone, which is the part of the ocean closest to the coast, characterized by nutrient-rich waters and a high concentration of marine life.

Phillips says the sea turtles were found crossing over to shallower waters and closer to shore, but it did not appear that they were transitioning to their next life stage, where they typically move to shallow habitats and feed off the bottom. Instead, the turtles seemed to approach the shore, then turned to avoid it.

“That was interesting because we had these passive drifters that we released with them and many of them washed up shore and none of the turtles did,” Phillips says.  

She adds that if the turtles don't behave like passive particles drifting with the currents and can actively swim and control their position, then existing movement models could consider both factors to correct errors in projections.

Existing hypotheses about the early life stage of most sea turtle species suggested they live exclusively in oceanic environments, drift passively with ocean currents and typically do not return to their previous habitat once they transitioned to a new one. However, these assumptions lack research into actual movement behavior.

“Historically, all our information about this young life stage has been limited to opportunistic sightings of these little, hard-to-see animals from boats passing by, tracking work on hatchlings in the first 24 hours after leaving nesting beaches, or laboratory studies,” Mansfield says.

Previous work also focused on the North Atlantic and on loggerheads, a species that commonly nested on the east coast of the U.S.

“I think it’s important to get data from different places and put the puzzle together to get a bigger picture of what’s going on,” Phillips says. “Researchers tracking this species were finding that they were staying offshore. But now that turtles are tracked from more places, we are finding that there are more nuances to what goes on. Loggerheads, for instance, we found stay off the continental shelf located in the west coast of Florida.”

Mansfield says sea turtle tracking can be costly, labor intensive, and the technology has limitations.

“It’s really hard to follow and manually track a little turtle over time,” Mansfield says. “You have to fuel a boat with researchers who have a strong stomach to go into the ocean. Historically, technology just wasn’t there to put a tag on a turtle and use satellites to be able to remotely track where they went. Tags were battery powered and as big as a brick.”

Prior to her time at UCF, Mansfield figured out a method to safely tag and effectively track small turtles, thanks to more reliable tagging technology, which played a role in conducting this study and achieving its results. She also credits their partnership with Inwater Research Group in helping to catch and track smaller sea turtles.

This research into sea turtle movement during the “lost years,” provides data for conservationists to assess and manage risks from human activity.

“The Deepwater Horizon oil spill in 2010 was a bit of the origin story of this project,” Mansfield says. “If we have another oil spill, we need to know whether these animals [will be] transient through an area, stuck there due to currents, or if they’ll end up somewhere else.”

Data from this study is already driving conservation efforts, including a proposal for critical habitat designation under the Endangered Species Act for green sea turtles. This designation would complement earlier tracking data led by Mansfield, which established critical habitat for loggerheads — the sargassum algae nursery.

Mansfield and Phillips say if assumptions are that these animals are strictly oceanic, then they may not be protecting them completely or addressing what they need for their eventual recovery.

“If sea turtles are occurring on the continental shelf, we suggest renaming this life stage to ‘dispersal stage’ to account their behavior,” Mansfield says. “This is important nuance in their life history, and the new terminology reflects a better understanding of sea turtle behavior, revealing more about these lost years.”

Funding information

Funding and support for this research was provided in part by the NOAA Oil Spill Supplemental Spend Plan, NOAA Southeast Fisheries Science Center, Florida RESTORE Act Centers of Excellence Program administered through the Florida Institute of Oceanography, National Fish and Wildlife Foundation, Friends of Gumbo Limbo Gordon J. Gilbert Grant, Microwave Telemetry Christiane Howey Rising Scholar Award, U.S. National Science Foundation Graduate Research Fellowships Program, UCF Boyd Lyon Memorial Fellowship, National Research Council Research Associateship Program, and the University of Central Florida.

Researchers’ credentials

Phillips, doctoral graduate, integrative and conservation biology, UCF; postdoctoral researcher, University of Massachusetts Amherst

Katherine Mansfield, professor, Department of Biology, UCF; director, Marine Turtle Research Group; and Davis-Shine Endowed Professorship in Conservation Biology

Nathan Putman, senior scientist, LGL Ecological Research Associates


MSU researchers glean photosynthetic insights from volcanic hot springs




Michigan State University





Images

EAST LANSING, Mich. – Italy’s Phlegraean Fields is a hotspot of volcanic activity — an ever-shifting landscape pocketed with acidic hot springs. This huge caldera is a part of the Campanian volcanic arc, which includes Mount Vesuvius, whose eruption wiped out the Roman city of Pompeii in 79 C.E. Yet, despite the hostile and scalding conditions of this environment, some microorganisms thrive. And researchers at Michigan State University are taking notice, hoping to uncover new information about how a particular alga survives in such extreme conditions.

In a new paper published in Plant Physiology, researchers in the MSU-DOE Plant Research Laboratory and the Walker lab — in collaboration with the Shachar-Hill lab of the Department of Plant Biology — are studying Cyanidioschyzon merolae, or C. merolae, and its unique ability to photosynthesize its own food. Understanding how C. merolae operates in such extreme conditions can help scientists better extrapolate — or improve upon — the process of photosynthesis, a function vital to all life on Earth.

Science has only described a narrow slice of how nature has dealt with the same challenges, but in different ways,” said Berkley Walker, the principal investigator for this study. The paper “did a great job of determining that the way we commonly see something being done is not the way it has to be done.”

This study looks at the carbon-concentrating mechanism, or CCM, in C. merolae. Many photosynthetic organisms use a CCM to boost the efficiency of photosynthesis. The CCM acts as a delivery driver, taking carbon dioxide and placing it where it can be best utilized.

At present, the CCM is well understood in plants, but only well characterized for a handful of algae species. 

“C. merolae is a very simple organism, so it doesn’t have all the structures and abilities that people typically associate with how a carbon-concentrating mechanism works,” said Anne Steensma, graduate student in the Department of Plant Biology and the Molecular Plant Sciences graduate program. She is a co-first author of this study. “Our paper gets at what the . . . basic features that you need to build a carbon-concentrating mechanism are.”

Working with collaborators from the MSU Department of Statistics and Probability, the researchers devised mathematical models to simulate C. merolae. A lot of effort went into devising and refining this model of the algae so researchers can continue to use it in further studies.

“A big challenge in this study was figuring out how to make sense of how the many different parameters we were plugging into our model worked to interact with each other,” said Joshua Kaste, a co-first author on this paper alongside Steensma. “This made our collaboration with Dr. Chih-Li Sung and Junoh Heo in the statistics department vitally important.”

To create this model, the researchers input data that would allow the model to act as a C. merolae cell would in real life, or as close to it as possible. It’s a bit like giving an actor a script: You know the words the actor will say, but not every detail of their performance. The components of the CCM that the researchers best understand is the script, coding the computer to create a model of the mechanism to as much accuracy as possible.

Having this model allows the researchers to input new conditions to see how the algae might respond. For example, they can remove parts of the model and see if it breaks the function of the CCM. This can help researchers narrow which parts of the algae are vital to the CCM.

“This shows us the ‘minimal path forward’ for engineering a carbon-concentrating mechanism,” said Walker, who also serves as an associate professor in the PRL and the Department of Plant Biology. “The other way to look at it is that maybe we can improve this simple carbon-concentrating system in C. merolae and achieve even greater growth under the extreme environments that it lives under.”

This research was funded from the Division of Chemical Sciences, Geosciences and Biosciences, Office of Basic Energy Sciences of the United States Department of Energy (DOE) (grant number DE-FG02-91ER20021). Additional funding came from the DOE (grant number DE-SC0018269), the National Institute of General Medical Sciences of the National Institutes of Health, the National Science Foundation Research Traineeship Program and the National Science Foundation.

By Kara Headley

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