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)
Monday, October 21, 2024
Catching prey with grappling hooks and cannons
ETH Zurich
image:
Cryo-electron tomogram (left) and 3D model (right) of the onboard cannon of the hunting bacterium Aureispira.
Countless bacteria call the vastness of the oceans home, and they all face the same problem: the nutrients they need to grow and multiply are scarce and unevenly distributed in the waters around them. In some spots they are present in abundance, but in many places they are sorely lacking. This has led a few bacteria to develop into efficient hunters to tap into new sources of sustenance in the form of other microorganisms.
Although this strategy is very successful, researchers have so far found only a few predatory bacterial species. One is the soil bacterium Myxococcus xanthus; another is Vampirococcus, which sucks its prey dry like a vampire.
In a new study, researchers at ETH Zurich led by Martin Pilhofer, Professor at the Department of Biology, along with his colleagues Yun-Wei Lien and Gregor Weiss, have now presented another of these rare bacterial predators: the filamentous marine bacterium Aureispira.
Among the molecular structures that the researchers have identified in Aureispira are ones that resemble grappling hooks and serve a similar purpose. The bacterium also has a kind of bolt gun that it uses to kill its prey.
Like a pirate ship in search of a potential victim, Aureispira swiftly glides over solid surfaces towards its prey, such as Vibrio bacteria. If the attacker is itself free-floating in water, it waits for its prey to approach. As soon as there is close contact, the grappling hooks become entangled with the victim’s flagella, and it can no longer escape.
Within seconds, Aureispira fires its on-board cannons to punch holes in the Vibrio bacterium’s membrane. In collaboration with the laboratory of ETH Professor Roman Stocker, the researchers were able to show that the cell components that leak out of the victim are quickly taken up by the predator as food. “The whole scene resembles a pirate raid on another ship,” Pilhofer says with a grin.
It’s only when the nutrient concentration in its environment is low that Aureispira becomes predatory. As long as the supply of nutrients is sufficient, the pirate bacterium refrains from catching prey and stands down its arsenal of weapons. However, putting the bacterium on a diet awakens its desire to hunt and causes the cell to rebuild the cannons and grappling hooks. Scientists call this selectively predatory lifestyle ixotrophy. Together with Martin Polz's group at the University of Vienna, the researchers were also able to find evidence that this predatory lifestyle does not only occur in the laboratory but actually in marine samples.
New imaging reveals details
The researchers used several imaging techniques, including light microscopy and cryo-electron microscopy, to understand the function and molecular structure of the grappling hooks and cannons.
This method made it possible to preserve and analyse molecular structures free of artefacts and in their cellular context. With an enhanced version of the method, it’s even possible to determine the molecular structure of the proteins that make up the bacterium’s weapons. “All of these imaging techniques are available at ETH Zurich’s ScopeM competence centre, which made this study possible in the first place,” Weiss says.
What are the findings good for? “First and foremost, this is basic research driven by our curiosity,” Pilhofer says. He and his colleague Weiss have been working for ten years to elucidate contractile injection systems – the name given to the pirate bacteria’s on-board cannons.
In other predatory bacteria, contractile injection systems are often also loaded with toxins to kill the prey immediately. It’s conceivable that such bacterial bolt guns could be loaded with active ingredients for injection into individual cells with the help of a molecular machine.
Certain predatory bacteria are known to prey on cyanobacteria, or blue-green algae. That means they could be used to combat algal blooms or to stop mass propagation of Vibrio bacteria. “These bacterial predators are very efficient at what they do,” Weiss says.
Credit: Devin Bittner/FSU College of Arts and Sciences
Oct. 17, 2024
TALLAHASSEE, Fla. — Hurricanes are massive, complex systems that can span hundreds of miles as they swirl around the low pressure of the storm’s eye. In such a complicated situation, predicting how powerful a hurricane will grow is a difficult undertaking.
A new collaboration between researchers in South Korea and Florida State University is improving hurricane forecasting by incorporating the effects of sea spray into the models that predict hurricane behavior. The work was published in Environmental Research Letters.
“We know forecasts predicting hurricane tracks are pretty good most of the time, but the intensity forecasts have traditionally not been as good, and we're trying to figure out why,” said Mark Bourassa, a professor in the FSU Department of Earth, Ocean and Atmospheric Science and paper co-author.
As hurricanes churn through the ocean, wind and waves at the surface disperse droplets of water into the air, known as sea spray. As these droplets of warm water evaporate, they cool while releasing heat and moisture into the atmosphere near the ocean surface. The heat lifts more moisture-laden air, a process that powers hurricanes.
The researchers looked at data from probes dropped by hurricane hunter airplanes and found there was a lot more thermal energy being transferred from the ocean into the air than they expected. That pointed to a potentially overlooked feature that was influencing storm intensity.
Previous studies into the role of sea spray in hurricane intensification relied on proxy measurements such as wind speed to approximate how sea spray reduces drag, which also increases the intensity in modeled storms. But those simplifications didn’t capture how spray increased the energy fueling storms, especially for wind speeds greater than 20 meters per second.
The weather model used by South Korean and FSU researchers included a wave model to provide greater accuracy for sea spray production and incorporated changes in the heat and moisture transferred to the atmosphere.
“It’s an amazing amount of energy that we've been missing in these storms,” Bourassa said. “When we incorporated data showing how sea spray changes the flow of heat and moisture in a storm, we found that intensity forecasts were remarkably better than they were when we ran the same model without that single change.”
To validate their findings, the research team analyzed four major Atlantic Ocean hurricanes — Ida (2021), Harvey (2017), Michael (2018), and Ian (2022) — which caused significant damage in the United States. With the help of colleagues in Korea, they also examined four Pacific Ocean typhoons.
Existing science is typically reliable at predicting a hurricane’s path, but meteorologists want to refine their modeling to better understand and forecast the intensity of storms. This research suggests that operational models could be modified to provide better intensity forecasts.
Future research motivated by this paper could focus on rapid intensification of storms, Bourassa said, helping to add another piece to the complicated puzzle that is hurricane forecasting.
Research team members from FSU were Chaehyeon Chelsea Nam, an assistant professor in the Department of Earth, Ocean and Atmospheric Science; DW Shin and Steven Cocke, research scientists at the FSU Center for Ocean-Atmospheric Prediction Studies; Sinil Yang of the APEC Climate Center, Republic of Korea; Dong-Hyun Cha of Ulsan National Institute of Science and Technology; and Baek-Min Kim of Pukyong National University, Republic of Korea.
This research was supported by the Korea Hydrographic and Oceanographic Agency, the Ministry of Oceans and Fisheries of Korea, the Korea Environment Industry & Technology Institute, Korea Ministry of Environment, the National Research Foundation of Korea, and the Korea Meteorological Administration Research and Development Program.
Unveiling the pivotal influence of sea spray heat fluxes on hurricane rapid intensification
Mpox in Africa was neglected during the previous outbreak, and requires urgent action and investment by leaders now to prevent global spread
PLOS
Mpox in Africa was neglected during the previous outbreak, and requires urgent action and investment by leaders now to prevent global spread, claim experts from The Independent Panel for Pandemic Preparedness and Response, ex-NZ Prime Minister Helen Clark, former Liberian President and Nobel Peace Prize winner Ellen Johnson Sirleaf, and other global health specialists.
Article Title: Mpox: Neglect has led to a more dangerous virus now spreading across borders, harming and killing people. Leaders must take action to stop mpox now
Author Countries: Australia, Belgium, Canada, Columbia, Kenya, Liberia, Mexico, New Zealand, Nigeria, Peru, Sweden, Switzerland, United Kingdom, United States
Funding: The Bill and Melinda Gates Foundation is supporting the ongoing work of The Independent Panel for Pandemic Preparedness and Response under INV-059481. CM, HEM, AN are consultants under this grant. CM led the writing and coordination of this manuscript. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing Interests: The authors have declared that no competing interests exist.
Why do we love carbs? The origins predate agriculture and maybe even our split from Neanderthals
Study co-led by UB finds the gene for starch-digesting saliva may have first duplicated more than 800,000 years ago, seeding the genetic variation that shapes our modern diet
University at Buffalo
image:
The lab of Omer Gokcumen helped analyze the genomes of 68 ancient humans for answers about our ability to begin breaking down starch in the mouth.
Credit: Meredith Forrest Kulwicki/University at Buffalo
BUFFALO, N.Y. —If you’ve ever struggled to reduce your carb intake, ancient DNA might be to blame.
It has long been known that humans carry multiple copies of a gene that allows us to begin breaking down complex carbohydrate starch in the mouth, providing the first step in metabolizing starchy foods like bread and pasta. However, it has been notoriously difficult for researchers to determine how and when the number of these genes expanded.
Now, a new study led by the University at Buffalo and the Jackson Laboratory (JAX), reveals how the duplication of this gene — known as the salivary amylase gene (AMY1) —may not only have helped shape human adaptation to starchy foods, but may have occurred as far back as more than 800,000 years ago, long before the advent of farming.
Reported today in the Oct. 17 advanced online issue of Science, the study ultimately showcases how early duplications of this gene set the stage for the wide genetic variation that still exists today, influencing how effectively humans digest starchy foods.
“The idea is that the more amylase genes you have, the more amylase you can produce and the more starch you can digest effectively,” says the study's corresponding author, Omer Gokcumen, PhD, professor in the Department of Biological Sciences, within the UB College of Arts and Sciences.
Amylase, the researchers explain, is an enzyme that not only breaks down starch into glucose, but also gives bread its taste.
Gokcumen and his colleagues, including co-senior author, Charles Lee, professor and Robert Alvine Family Endowed Chair at JAX, used optical genome mapping and long-read sequencing, a methodological breakthrough crucial to mapping the AMY1 gene region in extraordinary detail. Traditional short-read sequencing methods struggle to accurately distinguish between gene copies in this region due to their near-identical sequence. However, long-read sequencing allowed Gokcumen and Lee to overcome this challenge in present-day humans, providing a clearer picture of how AMY1 duplications evolved.
Ancient hunter-gatherers and even Neanderthals already had multiple AMY1 copies
Analyzing the genomes of 68 ancient humans, including a 45,000-year-old sample from Siberia, the research team found that pre-agricultural hunter-gatherers already had an average of four to eight AMY1 copies per diploid cell, suggesting that humans were already walking around Eurasia with a wide variety of high AMY1 copy numbers well before they started domesticating plants and eating excess amounts of starch.
The study also found that AMY1 gene duplications occurred in Neanderthals and Denisovans.
“This suggests that the AMY1 gene may have first duplicated more than 800,000 years ago, well before humans split from Neanderthals and much further back than previously thought,” says Kwondo Kim, one of the lead authors on this study from the Lee Lab at JAX.
“The initial duplications in our genomes laid the groundwork for significant variation in the amylase region, allowing humans to adapt to shifting diets as starch consumption rose dramatically with the advent of new technologies and lifestyles,” Gokcumen adds.
The seeds of genetic variation
The initial duplication of AMY1 was like the first ripple in a pond, creating a genetic opportunity that later shaped our species. As humans spread across different environments, the flexibility in the number of AMY1 copies provided an advantage for adapting to new diets, particularly those rich in starch.
“Following the initial duplication, leading to three AMY1 copies in a cell, the amylase locus became unstable and began creating new variations," says Charikleia Karageorgiou, one of the lead authors of the study at UB. “From three AMY1 copies, you can get all the way up to nine copies, or even go back to one copy per haploid cell.”
The complicated legacy of farming
The research also highlights how agriculture impacted AMY1 variation. While early hunter-gatherers had multiple gene copies, European farmers saw a surge in the average number of AMY1 copies over the past 4,000 years, likely due to their starch-rich diets. Gokcumen’s previous research showed that domesticated animals living alongside humans, such as dogs and pigs, also have higher amylase gene copy numbers compared to animals not reliant on starch-heavy diets.
“Individuals with higher AMY1 copy numbers were likely digesting starch more efficiently and having more offspring,” Gokcumen says. “Their lineages ultimately fared better over a long evolutionary timeframe than those with lower copy numbers, propagating the number of the AMY1 copies.”
The findings track with a University of California, Berkeley-led study published last month in Nature, which found that humans in Europe expanded their average number of AMY1 copies from four to seven over the last 12,000 years.
“Given the key role of AMY1 copy number variation in human evolution, this genetic variation presents an exciting opportunity to explore its impact on metabolic health and uncover the mechanisms involved in starch digestion and glucose metabolism,” says Feyza Yilmaz, an associate computational scientist at JAX and a lead author of the study. “Future research could reveal its precise effects and timing of selection, providing critical insights into genetics, nutrition, and health.”
Other UB authors on the study include PhD students Petar Pajic and Kendra Scheer.
The research was a collaboration with the University of Connecticut Health Center and was supported by the National Science Foundation and the National Human Genome Research Institute, National Institutes of Health.
Reconstruction of the human amylase locus reveals ancient duplications seeding modern-day variation
Article Publication Date
17-Oct-2024
Why do we love carbs? The origins predate agriculture and maybe even our split from Neanderthals
Study from The University of Buffalo and The Jackson Laboratory for Genomic Medicine finds the gene for starch-digesting saliva may have first duplicated more than 800,000 years ago, seeding the genetic variation that shapes our modern diet
Jackson Laboratory
image:
A graphiical representation of the amylase gene locus and how it evolved to influence how humans digest complex carbohydrates like bread and pasta.
If you’ve ever struggled to reduce your carb intake, ancient DNA might be to blame.
It has long been known that humans carry multiple copies of a gene that allows us to begin breaking down complex carbohydrate starch in the mouth, providing the first step in metabolizing starchy foods like bread and pasta. However, it has been notoriously difficult for researchers to determine how and when the number of these genes expanded. Now a new study led by The University of Buffalo (UB) and The Jackson Laboratory (JAX) showcases how early duplications of this gene set the stage for the wide genetic variation that still exists today, influencing how effectively humans digest starchy foods.
The study's findings, reported in the Oct. 17 advanced online issue of Science, reveal that the duplication of this gene—known as the salivary amylase gene (AMY1) —may not only have helped shape human adaptation to starchy foods, but may have occurred as far back as more than 800,000 years ago, long before the advent of farming.
"The idea is that the more amylase genes you have, the more amylase you can produce and the more starch you can digest effectively,” said the study's corresponding author, Omer Gokcumen, PhD, professor in the Department of Biological Sciences, within the UB College of Arts and Sciences. Amylase, the researchers explained, is an enzyme that not only breaks down starch into glucose, but also gives bread its taste.
Gokcumen and his colleagues, including co-senior author, Charles Lee, professor and Robert Alvine Family Endowed Chair at JAX, used optical genome mapping and long-read sequencing, a methodological breakthrough crucial to mapping the AMY1 gene region in extraordinary detail. Traditional short-read sequencing methods struggle to accurately distinguish between gene copies in this region due to their near-identical sequence. However, long-read sequencing allowed Gokcumen and Lee to overcome this challenge in present-day humans, providing a clearer picture of how AMY1 duplications evolved.
Ancient hunter-gatherers and even Neanderthals already had multiple AMY1 copies
Analyzing the genomes of 68 ancient humans, including a 45,000-year-old sample from Siberia, the research team found that pre-agricultural hunter-gatherers already had an average of four to eight AMY1 copies per diploid cell, suggesting that humans were already walking around Eurasia with a wide variety of high AMY1 copy numbers well before they started domesticating plants and eating excess amounts of starch.
The study also found that AMY1 gene duplications occurred in Neanderthals and Denisovans. “This suggests that the AMY1 gene may have first duplicated more than 800,000 years ago, well before humans split from Neanderthals and much further back than previously thought,” said Kwondo Kim, one of the lead authors on this study from the Lee Lab at JAX.
“The initial duplications in our genomes laid the groundwork for significant variation in the amylase region, allowing humans to adapt to shifting diets as starch consumption rose dramatically with the advent of new technologies and lifestyles,” said Gokcumen.
The seeds of genetic variation
The initial duplication of AMY1 was like the first ripple in a pond, creating a genetic opportunity that later shaped our species. As humans spread across different environments, the flexibility in the number of AMY1 copies provided an advantage for adapting to new diets, particularly those rich in starch.
"Following the initial duplication, leading to three AMY1 copies in a cell, the amylase locus became unstable and began creating new variations," said Charikleia Karageorgiou, one of the lead authors of the study at UB. “From three AMY1 copies, you can get all the way up to nine copies, or even go back to one copy per haploid cell."
The complicated legacy of farming
The research also highlights how agriculture impacted AMY1 variation. While early hunter-gatherers had multiple gene copies, European farmers saw a surge in the average number of AMY1 copies over the past 4,000 years, likely due to their starch-rich diets. Gokcumen’s previous research showed that domesticated animals living alongside humans, such as dogs and pigs, also have higher AMY1 copy numbers compared to animals not reliant on starch-heavy diets.
"Individuals with higher AMY1 copy numbers were likely digesting starch more efficiently and having more offspring,” Gokcumen said. “Their lineages ultimately fared better over a long evolutionary timeframe than those with lower copy numbers, propagating the number of the AMY1 copies."
The findings track with a University of California, Berkeley-led study published last month in Nature, which found that humans in Europe expanded their average number of AMY1 copies from four to seven over the last 12,000 years.
“Given the key role of AMY1 copy number variation in human evolution, this genetic variation presents an exciting opportunity to explore its impact on metabolic health and uncover the mechanisms involved in starch digestion and glucose metabolism,” said Feyza Yilmaz, an associate computational scientist at JAX and a lead author of the study. “Future research could reveal its precise effects and timing selection, providing critical insights into genetics, nutrition, and health.”
The research was a collaboration with the University of Connecticut Health Center and was supported by the National Science Foundation and the National Institutes of Health – National Human Genome Research Institute.
Journal
Science
Method of Research
Experimental study
Subject of Research
People
Article Title
Reconstruction of the human amylase locus reveals ancient duplications seeding modern- 2 day variation
Article Publication Date
17-Oct-2024
Drones prove effective way to monitor maize re-growth, researchers report
Journal of Remote Sensing
image:
Researchers used unmanned aerial vehicle to conduct a survey of maize lodging experiments in Hebei Province.
Maize, or corn, grows tall, with thin stalks that boast ears of the cereal grain used in food production, trade and security globally. However, due to rain, wind and other increasingly extreme weather events, the maize falls down, risking the entire crop. Called lodging, the physical fall results in shorter plants and overlapping leaves — both of which negatively impact the plant’s ability to grow.
Conventional lodging prevention and mitigation requires many agricultural technicians significant time to investigate the crop fields, according to a team of researchers based in China. They said that a potential solution could be a rapid, non-destructive method of remote monitoring, called Unmanned Aerial Vehicle (UAV)-based hyperspectral imaging. The team recently found that the method can accurately evaluate maize recovery without the time or expense of individuals physically inspecting the crops.
“UAV-based hyperspectral imaging technology revolutionizes the way we monitor and assess the recovery of lodging crops,” said first author Qian Sun, a doctor at Yangzhou University. “This advanced method allows for rapid, non-destructive evaluation of plant health and growth. This not only aids in better understanding the state of plants but also enhances overall crop management practices, potentially leading to more effective interventions and improved agricultural production.”
UAV-based hyperspectral imaging involves using drone-like vehicles that can fly with limited human input and examine the field. For every pixel in an image, the method determines the multiple spectral bands — a much more detailed understanding than human eyesight, which only sees across three bands of visible light.
The researchers used UAV-based hyperspectral imaging to assess canopy height and coverage, as well as physiological activity of maize, such as chlorophyll production — evidence of photosynthesis, an energy-producing process that may reduce if stalks are shorter or leaves are obscured by other plants after lodging. This two-prong approach is necessary for accurate assessment, the researchers said, as measuring just one variable provides an incomplete picture of the maize’s regrowth progress.
“This technique allows for more precise monitoring and assessment of lodging crop conditions compared to traditional methods,” said co-corresponding author Xiaohe Gu, a professor with the Research Center of Information Technology, Beijing Academy of Agriculture and Forestry Sciences. “In particular, this study proposed a comprehensive evaluation framework that combines the canopy structure and the physiological activity, delivering a precise and efficient means of assessing the recovery grades of lodging maize.”
They determined that their imaging approach could accurately assess both the canopy stature and the physiological activity, providing information to farmers who could then make adjustments to the crops to assist in their recovery.
“The ultimate goal is to revolutionize agricultural practices through the widespread adoption of UAV-based hyperspectral technology,” said co-author author Liping Chen, a professor with the Research Center of Information Technology, Beijing Academy of Agriculture and Forestry. “By making this advanced tool a standard component in crop monitoring, we aim to significantly enhance the accuracy and efficiency of assessing plant health and recovery. This will enable farmers and agronomists to manage crops more effectively, optimize interventions, and ultimately increase yield and productivity.”
Other co-authors on the study are Baoyuan Zhang, Xuxhou Qu and Yanglin Cui, all with the Research Center of Information Technology, Beijing Academy of Agriculture and ForestrySciences ; and co-corresponding author Meiyan Shu, College of Information and Management Science at Henan Agricultural University.
The National Key Research and Development Program of China supported this work.
Evaluation of Growth Recovery Grade in Lodging Maize via UAV-Based Hyperspectral Images
Materials of the future can be extracted from wastewater
A group of researchers is on the way to revolutionizing what biomass from wastewater treatment plants can be used for. Biopolymers from bacteria can be a sustainable alternative to oil-based products, and phosphorus and other minerals can also be harvested
"The perspective is enormous, because you’re taking something that is currently waste and making high-value products from it."
This is what Professor Per Halkjær Nielsen, Department of Chemistry and Bioscience at Aalborg University in Denmark, says about the results of a research project that utilizes surplus biomass in wastewater treatment plants in new ways. The focal point is biopolymers that can be described as long chains of molecules that are bound to each other and that are produced by living organisms, including bacteria. Today, synthetic polymers produced in the petrochemical industry from crude oil are used in many contexts including plastics, textile fibres, adhesives and paints. But with future production of biopolymers at wastewater treatment plants, it will be possible to extract a sustainable alternative to oil-based polymers through a waste product.
"In short, the work on biopolymers is about producing a lot of biomass in wastewater treatment plants that is actually bacteria that eat everything that enters the treatment plant so that only the pure water remains," explains Professor Per Halkjær Nielsen.
"Every single day, many tons of biomass are produced, depending on how big the treatment plant is, and this is typically converted in a biogas reactor so that you get energy out of it. A large part of the bacteria consists of biopolymers, i.e. the adhesive material around them, and biopolymers are in demand in the industry as a sustainable alternative to oil-based polymers."
Biopolymers can be used as a binding agent in paper and in building materials, and they can be used as a material for flocculation where small particles clump together and settle as part of the water purification of harbour sludge, lakes and wastewater treatment plants. An added bonus is that biopolymers from wastewater treatment plants appear to be fire-retardant. Thus, there is a potentially large market for biopolymers if they can be produced commercially in a sustainably way, and there is potential for this, according to the research project REThiNk.
In a wastewater treatment plant, there are several hundred different species of bacteria that produce many types of biopolymers with different properties. These bacteria use the biopolymers as an adhesive to form colonies and adhere to surfaces so they are not just flushed out of the treatment plant. These biopolymers can be extracted by changing the pH and temperature of the water to produce cellulose and gelatinous biopolymers that can be used for a variety of industrial products. The expectation is that it will be possible to create factories that produce biopolymers from Danish wastewater treatment plants, and the potential is great, since hundreds of thousands of tons of bacteria are produced annually in Denmark alone. As an added benefit, minerals and other valuable components can be harvested from the wastewater that arrives at the treatment plants, such as phosphorus which is on the EU's list of critical raw materials that may be difficult to obtain in the future.
The goal of the REThiNk project is to create the foundation for industrial scale-up in the short term so that in the long term there will be a real revolution in recycling biomass from wastewater treatment plants all over the world and not just in Denmark. It also requires mapping bacteria at wastewater treatment plants around the world so that it is possible to predict how each of them can play a role in biopolymer production, phosphorus extraction, etc.
"There is great potential if companies can see that the product can be used for something and thus want to invest in testing and developing it. And this requires that we build pilot scale plants so that we can produce not just grams, but kilograms and in a few years' time many tons. We can take 20-30 percent of the biomass and turn it into biopolymers that can replace petroleum products, but it actually also replaces seaweed. Today, many biopolymers are produced from seaweed from large kelp forests that are endangered. So if we can find other ways to extract biopolymers, it is a clear advantage for the environment and biodiversity as well," Per Halkjær Nielsen points out.
In the REThiNk project, Aalborg University is collaborating with Delft University in the Netherlands and Aarhus University, and the researchers have just published their results in the scientific journal Current Opinion in Biotechnology.
About biopolymers: Polymers are substances that consist of molecules bonded to each other in long molecular chains. Biopolymers are formed by living organisms, one of the best known being cellulose from trees and plants. Synthetic polymers are artificially produced in the petrochemical industry based on crude oil and are used in plastics, textile fibres, adhesives and paints, among other things. The physical properties of polymers have an impact on what they can be used for (source: Lex.dk, https://denstoredanske.lex.dk/polymer).
American lobsters along Maine’s coast have relocated to new habitats, while the population simultaneously shrunk in abundance and grew older, according to a new study by University of Maine researchers.
For decades, the vast majority of adult lobsters resided in boulder shelter habitats. This knowledge helped inform longtime conservation efforts and regulations within the more than $740 million fishery.
A team of UMaine scientists, however, found that from 1995-2021, occupancy of boulder habitats dropped 60%. Meanwhile, the number of lobsters residing in sediment or featureless ledge habitats, both of which have little to no geological features to use as shelters, increased 633% and 280%, respectively. Lobster population density across all types of habitats declined too, meaning they are fewer in number and their populations are more spread out.
Water temperatures increased nearly 3 degrees Celcius from 1995-2021 across these habitats, according to researchers, showing how lobsters and their habitats are changing with the climate. Kelp abundance declined across lobster habitats, while diminutive algal turfs — small green mats containing multiple species of algae — increased.
“These differences in the way lobsters use their habitats provide context for the lobster stock assessment that helps to determine the health of the entire lobster population,” said Robert Jarrett, lead author of the study and marine biology Ph.D. student. “Some of the annual lobster surveys used in the assessment, like those from the Maine Department of Marine Resources, are restricted in the types of habitats that they can sample, so these findings about habitat help fill in some information gaps and show that over time the lobsters may be shifting between which surveys catch them better.”
Jarrett and his colleagues published their findings in the journal Marine Ecology Progress Series. Co-authors include Damian Brady, Agatha B. Darling Professor of Oceanography; Richard Wahle, former director of the Lobster Institute, and Bob Steneck, professor emeritus of oceanography, marine biology and marine policy.
The team investigated 20 sites along Maine’s coast, from York to Jonesport. They dove 10 meters below the surface to count and measure lobster, as well as to collect data on habitat and temperature. The team also reviewed historic data for the same sites dating back to the 1990s.
While overall population density has declined, the mean size of an adult lobster was greater in 2021 than in 1996. According to the study, the increase in mean size is partially the result of fewer juvenile lobsters residing in these habitats. While lobsters in the Gulf of Maine are now larger, the team observed that the majority, or 93%, were still smaller than 83 millimeters, the minimum legal size to be caught and sold — a promising sign for the fishery.
Lobsters are also now favoring open spaces within their habitats over rocky shelters than previously. The percentage of lobsters living under rocky shelters dropped 34% from 2000-2019, while those using no shelter at all increased 168%. The number of lobsters that reside underneath beds of algae have also grown 160%.
According to researchers, demographic shifts among Gulf of Maine lobsters — habitat, size and population density — may have resulted from a drop in baby lobsters surviving to the seafloor and less competition between individual lobsters. The lack of predators might have also influenced more lobsters to move away from boulders to more open habitats, forgoing rock shelters for cover with only algae to hide under.
“When you consider that this is one of the best studied commercially important marine species in the world, it is stunning that we keep getting surprised by our iconic lobster,” Steneck said.
This study is the latest example of how UMaine students and faculty are preserving and propelling the state’s blue economy, industries that use ocean resources for economic growth without jeopardizing the environment.
Through innovation and workforce development, the university broadens insight into ecological and sociological changes that affect the state’s coastal communities and businesses. Its faculty and students are also exploring opportunities for new sectors and markets and investigating potential resources to mitigate the ramifications of climate change.
Bolstering these efforts is the UMaine Marine Aligned Research, Innovation, and Nationally-recognized Education (MARINE) Initiative, which fosters collaboration and synergy among researchers, industry, government and communities. Together, they integrate and innovate transdisciplinary marine research, education and outreach to enhance the socioeconomic well-being of people in Maine and beyond.
“This study exemplifies how the University of Maine supports Maine’s blue economy. In a changing Gulf of Maine, sustainable management of the largest fishery in North America requires better understanding how lobsters are using habitat” said Brady, also the principal investigator of a National Science Foundation-funded Navigating the New Arctic project that supported this work
