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Tag: Marine Science

  • Researchers Identify Unusually Large Bloom of Brown Algae in Gulf of Maine

    Researchers Identify Unusually Large Bloom of Brown Algae in Gulf of Maine

    Newswise — DURHAM, N.H.—Researchers at the University of New Hampshire, along with other regional partners, have been monitoring the development of an expansive algal bloom that has formed in the Gulf of Maine—stretching more than a hundred miles from Massachusetts to Maine. The brown, coffee-colored bloom consists mostly of phytoplankton, or microalgae, that is not new to the waters off the coast of New England. However, the scientists all agree this is the first time it has been seen at such high concentrations at this time of the year in the Gulf of Maine.

    The bloom, or rapid growth of the algae, is predominately made up of dinoflagellate phytoplankton Tripos muelleri and has been found mostly in the water column under the surface. It first caught the attention of UNH scientists in April when they noticed significant changes in the ocean carbon dioxide (CO2) and pH levels they regularly monitor off the coast of New Hampshire.

    “We were seeing the lowest CO2 levels and highest pH levels in surface water that we have observed in our twenty years of monitoring samples in the Gulf of Maine,” said Doug Vandemark, research professor at UNH’s Ocean Process Analysis Laboratory. “We thought it might be related to the warming water in the Gulf of Maine and then we started to hear reports about marine filters being clogged with brown algae and other general nuisances from people working along the coast. We knew it wasn’t a coincidence.”

    Even though the bloom species was not known to be dangerous it was unusual, so the UNH team took a proactive approach and began to collect additional water samples to increase their monitoring which included phytoplankton counts, eDNA, nutrients and carbon analyses. At the same time, they started to hear from other local scientists, marine operators and fishermen who were also documenting the unusual conditions throughout the Gulf of Maine. Together they assembled an informal consortium to share observations and data. The group now consists of over a dozen partners from Maine to Rhode Island and beyond. A partial list includes researchers at the National Oceanic and Atmospheric Administration (NOAA), Woods Hole Oceanographic Institution (WHOI), University of Maine, St. Joseph’s College of Maine, University of Massachusetts, Gulf of Maine Research Institute,  Bigelow Laboratory for Ocean Sciences and the Northeastern Regional Association of Coastal Ocean Observing Systems (NERACOOS).

    According to experts at WHOI’s Harmful Algal Bloom (HAB) observing network, the phytoplankton dominating this bloom, Tripos muelleri, does not produce a toxin and doesn’t present any known risks to humans or animals. However, high biomass blooms like this one have the potential to cause low oxygen conditions when they decay. This can negatively affect marine organisms, particularly ones inhabiting bottom waters and sediments. In general, seasonal blooms are a normal occurrence in high latitude marine ecosystems like the Gulf of Maine and are beneficial because the tiny plants provide food for animals and energy that fuels the ocean food web.

    “It’s completely normal to see this species in the waters of the Gulf of Maine but never at this intensity,” said Liz Harvey, associate professor of biological sciences. “At first it was intriguing but then it was larger than any of us had seen before and we thought wait this is different – and as researchers we want to understand the how and why and if it is a signal of a potentially changing Gulf of Maine.”

    Researchers say, in general, the high levels of phytoplankton seen in the spring usually decline in the summer months when nutrients that fuel the growth of phytoplankton decrease and animal populations like copepods, or small crustaceans, graze on them helping to reduce the bloom. However, this bloom of Tripos muelleri did not follow the traditional seasonal pattern. According to satellite imagery provided by NOAA, the phytoplankton bloom has steadily persisted since April and has been widespread, from Penobscot Bay to Martha’s Vineyard. It is still not clear why this bloom formed and how it has been sustained across such a large area. Scientists are considering a number of triggers during the spring including decreased wind, the mild winter and the fact that Gulf of Maine is one of the fastest warming regions in the world. The heavy regional rainfall this summer may have also contributed to the bloom’s uncommonly long duration.

    “We’re still looking for answers and there is more work to do,” said Chris Hunt, research assistant professor at UNH’s Ocean Process Analysis Laboratory. “We’ve documented the massive growth of this species and the resulting changes in oxygen, CO2 and pH, but we are all still working to figure out what the conditions were that triggered this bloom in the first place, allowed it to last for so long and what happens to all the cells and organic matter once the bloom is over?”

    Potential After Effects of the Bloom 

    The consortium of researchers has coordinated efforts to collect more water samples in the region over the coming months. Recent data shows that the bloom may be starting to fade along the shore but they are working to determine if this is also happening further offshore. The team is also attempting to monitor the Gulf of Maine closely for any signs of hypoxia, low oxygen conditions that can affect marine life. As the phytoplankton begins to fade, or die off, they sink to the bottom of the ocean and are consumed by bacteria, which can deplete oxygen and could have an effect on fish, shellfish and lobster. The last known time something like that happened with this same species along the East coast was almost fifty years ago in 1976 over the New York Bight when a large bloom created hypoxic conditions after it died off. This impacted commercial shellfish and fish stocks.

    “It is too soon to tell if this Tripos muelleri bloom might lead to a hypoxia event similar to the one in 1976,” said Vandemark. “What is important now is that we continue to monitor into the fall and then try to understand the bloom, any possible impacts and if we could expect more like it in the future.”

    The multi-pronged effort by the team of scientists to collect data includes UNH, joined by several other regional institutions that regularly collect water samples, to analyze key indicators like water temperature, salinity, chlorophyll, nutrients, CO2 and pH levels; continued tracking of the bloom by using satellite imagery of chlorophyll concentrations from NOAA; oxygen sensors on lobster traps deployed by commercial fishermen participating in the eMOLT program; and the collection of phytoplankton, zooplankton, nutrients, oxygen and carbon samples across the Gulf of Maine by NOAA’s NEFSC Ecosystem Monitoring surveys. The group of scientists will continue to monitor conditions over the next few months and are planning to meet as a working group in the fall to analyze all the data.

    Support for UNH Gulf of Maine monitoring is provided by the Gulf of Maine Marine Biodiversity Observation Network led by NERACOOS and the University of Maine which is funded by NOAA and the Bureau of Ocean Energy Management. Additional support is provided by NOAA’s Ocean Acidification program and the Office of Naval research.

    The University of New Hampshire inspires innovation and transforms lives in our state, nation and world. More than 16,000 students from all 50 states and 71 countries engage with an award-winning faculty in top-ranked programs in business, engineering, law, health and human services, liberal arts and the sciences across more than 200 programs of study. A Carnegie Classification R1 institution, UNH partners with NASA, NOAA, NSF and NIH, and received $260 million in competitive external funding in FY21 to further explore and define the frontiers of land, sea and space.

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    IMAGES FOR DOWNLOAD

    https://www.unh.edu/unhtoday/sites/default/files/phytonplankton_tripos_muelleri_002.png
    Caption: Image of phytoplankton Tripos muelleri under 4X magnification from a water sample taken at two meters in the ocean at the UNH CO2 buoy on July 23, 2023.
    Photo Credit: Liz Harvey / University of New Hampshire

    https://www.unh.edu/unhtoday/sites/default/files/satellite_images_chlorophyll_august_2023.png
    Caption: Satellite images of the Gulf of Maine compare chlorophyll concentrations from August 2023 to those from 2022.  The chlorophyll concentration in the left images shows high concentrations (yellow colors) throughout the region in 2023 (top row). The images of chlorophyll anomalies on the right, show chlorophyll concentrations in 2023 are up to 10 times greater than the long-term July average – indicating that the current concentrations of phytoplankton are unusually high.
    Image credit: Kimberly Hyde / NOAA Northeast Fisheries Science Center

    https://www.unh.edu/unhtoday/sites/default/files/water_sample_gom_may_2023_joe_vallino_whoi.jpg
    Caption: A nearshore Gulf of Maine water sample full of Tripos Muelleri collected in May 2023.  
    Photo credit: Joe Vallino / Marine Biological Laboratory

    https://www.unh.edu/unhtoday/sites/default/files/filters_clogged_with_phytoplankton_credit_katy_mcginnis_noaa.jpg
    Caption: Residue from phytoplankton spring bloom on filters collected in Gulf of Maine near Georges Bank by NOAA’s R/V Henry B. Bigelow in early May 2023.
    Photo credit: Katy McGinnis / NOAA

    University of New Hampshire

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  • Climate change: Emperor penguin breeding fails due to Antarctic sea ice loss

    Climate change: Emperor penguin breeding fails due to Antarctic sea ice loss

    Newswise — Four out of five emperor penguin colonies in the Bellingshausen Sea, Antarctica, saw no chicks survive to fledge successfully in the spring of 2022, reports a study published in Communications Earth & Environment. The study suggests that this complete breeding failure is a direct consequence of the unprecedented loss of sea ice recorded in the region in recent years due to climate change.

    Emperor penguin (Aptenodytes forsteri) colonies generally need stable ice attached to the land between April and January to ensure successful breeding and moulting. Any change in the extent of the Antarctic sea ice can affect their reproduction as chicks do not develop waterproof feathers until fledging.

    Peter Fretwell and colleagues used satellite images covering the period between 2018 and 2022 to monitor the presence of emperor penguins during the breeding season at five colonies in the Bellingshausen Sea in Antarctica. The colonies are known as Rothschild Island, Verdi Inlet, Smyley Island, Bryan Coast, and Pfrogner Point and range in size from around 630 pairs on Rothschild Island to around 3,500 pairs on Smyley Island.

    The authors found that four colonies — Verdi Inlet, Smyley Island, Bryant Coast, and Pfrogner Point —experienced total reproductive failure and were abandoned in the period after the sea ice broke up before the start of the fledging period in December 2022. The authors indicate that it is unlikely that any chicks survived to successfully fledge at these colonies. However, satellite images suggest that chicks did fledge successfully at Rothschild Island colony. The authors note that of the five colonies only Bryant Coast colony had been identified as having experienced total breeding failure prior to 2022.

    This is the first regional breeding failure of emperor penguins observed in the past 13 years in the region, and among the first evidence of the direct impact of Antarctic warming on the viability of emperor penguin populations.

    Scientific Reports

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  • Modeling ocean to understand natural phenomena

    Modeling ocean to understand natural phenomena

    BYLINE: Space Time Inc.

    Newswise — Associate Professor Yoshi N. Sasaki, a specialist in Physical Oceanography, is involved in research into rising sea levels—particularly in coastal areas of Japan. He spoke about what he has learned so far about the relationship between ocean currents, sea level and climate change, what research he is currently focusing on, and the appeal of research that uses numerical modeling to uncover natural phenomena.

    Understanding future changes in sea level

    It is a common view among researchers that the global mean sea level is rising. The only question now is, by how much will it rise?

    The graph below shows global average sea level, with tide-gauge data since 1880 and satellite data since 1993. It shows that the water level rose at a rate of about 1.5 to 2 millimeters per year in the 20th century, but has increased at a faster rate of about 3 millimeters per year in the 21st century. This speed is expected to increase further in the future as global warming continues.

    Indeed, on the US coast, for example in Florida, many people live on low land, and sea levels are rising faster than in other areas of the ocean. In such areas, dike building and migration are already being considered.

    Researchers are now focusing on detailed predictions of what will cause sea level changes, when, in which areas, and to what extent.

    As this graph is a ‘global average,’ the actual situation at different locations is much more nuanced than this alone reveals. To clarify this, simulations using numerical models are being carried out.

    Sea level is the sum of multiple factors

    Sea level rise does not occur uniformly across the globe, but varies greatly from one ocean region to another. The causes also vary between global changes and changes in some ocean regions.

    There are two main causes of sea level rise on average across the globe. The first is the thermal expansion of seawater due to warming caused by global warming. The second is the melting of glaciers and ice sheets due to global warming. Water that was previously trapped on land as ice flows into the sea, increasing the mass of seawater and causing sea levels to rise.

    There are many different mechanisms by which sea level changes in different ocean regions. To give a few examples: one, variations in ocean circulation. Due to the physics of geostrophic currents, the sea level in the Northern Hemisphere is higher on the right side and lower on the left side in relation to the direction of the ocean currents. Two, changes in atmospheric pressure. Three, changes in the ground—the ground also sinks and rises, which changes the height of the coastal water table.

    In other words, to predict sea level in an area, a combination of these factors needs to be taken into account. Specifically, the effects of each of these factors can be added together to estimate the actual rise in sea level, to some extent.

    Understanding natural mechanisms using numerical models

    My research involves computer simulations, using regional ocean models of the US. In principle, the model can reproduce the state of the ocean by feeding it with observed data such as atmospheric winds and temperatures.

    For example, if we know that a change in water levels is caused by wind fluctuations, we can make predictions of future changes in water levels by knowing what the winds will be like in the future.

    Although I simply said ‘By wind fluctuations,’ it is about understanding the mechanisms of nature. For me, it’s something very enjoyable that satisfies my intellectual curiosity.

    Naturally, it is not a straightforward process. Models are very complex, and to understand the mechanism, the model must first be able to reproduce the phenomena accurately. Once that is done, a ‘simpler model’ that reproduces the same situation can be developed, revealing new principles hidden in nature. We need to look at the results of the complex models to find the essence of what is important.

    When I was doing research in the US, I discovered a new mechanism that changed the ocean circulation. To someone outside the field, it would have looked like just a diagram, but after working on it for a very long time, it suddenly looked like important information that no one had ever seen before. This is the best part of research.

    Water level fluctuations along the coast of Japan

    Water levels along the Japanese coast are also currently rising, but it is known that they did not rise all the way through the 20th century—they peaked once around 1950 and then fell.

    Our research has shown that the peak around 1950 was dominated by wind effects. In particular, it seems to have been caused by fluctuations in ocean circulation due to wind fluctuations from a low-pressure system called the Aleutian Low. On the other hand, the rise in recent years has been found to be primarily due to the effects of heat and other factors at the sea surface.

    Assessing the impact of typhoons and storm surges

    In the future, typhoons and extratropical cyclones are predicted to become stronger. So far, research has been conducted on how sea level changes on long-term time scales of a decade or more, but the possibility that short-term fluctuations, such as storm surges, could cause major damage cannot be ignored.

    In order to assess such impacts, we need to know exactly how typhoons and extratropical cyclones will strengthen in the future, and how this will affect sea levels. I am currently working on this with young students, and we are hoping to get this project off the ground.

    Sea level rise is one aspect of the wider ocean

    Right now, the resolution of ocean models for global warming simulations is approximately 100 kilometers, and can be narrowed down to 10 kilometers at the finest. This may be sufficient for some ocean regions, but it is not sufficient at all for some topographies, so I would like to create more detailed models and incorporate methods such as statistics and machine learning to estimate.

    On the other hand, there is also a conflict between effective measures and the economic aspects. For example, in the US,there were very specific discussions about the cost of migration to avoid the influence of sea level rise and the cost of building dikes, and which is better. Once you know certain things, the rest is no longer in the field of science, but in the field of politics or in the field of society. It’s about how much accuracy society demands.

    I myself would like to go back to the theme of ocean currents and look for more interesting and important phenomena caused by ocean currents once I have gone through sea level rise. I think there are still many interesting phenomena caused by ocean currents, such as ocean circulation. My dream for the future is to elucidate the mechanisms of these phenomena.

    Friendships gained in Hawaii

    After completing my doctoral studies at Hokkaido University, I chose a post-doctoral research fellowship at the University of Hawai’i in the US as my first job. The University of Hawai’i was one of the world’s strongest universities in marine research, but it was a big decision for me to do research abroad where Japanese was not spoken. It was a tough decision for me, as I was so committed to my research that I felt that if I did not achieve good results in Hawai’i, I would not be able to return to Japan. But it was very rewarding. As well as research, Hawai’i is a tourist destination, so a lot of researchers come here as visitors. I made a lot of acquaintances and connections in this environment, and it still helps me to build an international network.

    Hokkaido University

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  • The modern sea spider had started to diversify by the Jurassic, study finds

    The modern sea spider had started to diversify by the Jurassic, study finds

    BYLINE: Laura Thomas

    Newswise — An extremely rare collection of 160-million-year-old sea spider fossils from Southern France are closely related to living species, unlike older fossils of their kind.

    These fossils are very important to understand the evolution of sea spiders. They show that the diversity of sea spiders that still exist today had already started to form by the Jurassic.

    Lead author Dr Romain Sabroux from the University of Bristol’s School of Earth Sciences, said: “Sea spiders (Pycnogonida), are a group of marine animals that is overall very poorly studied.

    “However, they are very interesting to understand the evolution of arthropods [the group that includes insects, arachnids, crustaceans, centipedes and millipedes] as they appeared relatively early in the arthropod tree of life. That’s why we are interested in their evolution.

    “Sea spider fossils are very rare, but we know a few of them from different periods. One of the most remarkable fauna, by its diversity and its abundance, is the one of La Voulte-sur-Rhône that dates back to the Jurassic, some 160 million years ago.”

    Unlike older sea spider fossils, the La Voulte pycnogonids are morphologically similar (but not identical) to living  species, and previous studies suggested they could be closely related to living sea spider families. But these hypotheses were restricted by the limitation of their observation means. As it was impossible to access what was hidden in the rock fossils, Dr Sabroux and his team travelled to Paris and set out to investigate this question with cutting-edge approaches.

    Dr Sabroux explained: “We used two methods to reinvestigate the morphology of the fossils: X-ray microtomography, to ‘look inside’ the rock, find morphological features hidden inside and reconstruct a 3D model of the fossilised specimen; and Reflectance Transformation Imaging, a picture technic that relies on varied orientation of the light around the fossil to enhance the visibility of inconspicuous features on their surface.

    “From these new insights, we drew new morphological information to compare them with extant species,” explained Dr Sabroux.

    This confirmed that these fossils are close relatives to surviving pycnogonids. Two of these fossils belong to two living pycnogonid families: Colossopantopodus boissinensis was a Colossendeidae while another, Palaeoendeis elmii was an Endeidae. The third species, Palaeopycnogonides gracilis, seems to belong to a family that has disappeared today.

    “Today, by calculating the difference between the DNA sequences of a sample of species, and using DNA evolution models, we are able to estimate the timing of the evolution that bind these species together,“ added Dr Sabroux.

    “This is what we call a molecular clock analysis. But quite like a real clock, it needs to be calibrated. Basically, we need to tell the clock: ‘we know that at that time, that group was already there.’ Thanks to our work, we now know that Colossendeidae, and Endeidae were already ’there’ by the Jurassic.”

    Now, the team can use these minimal ages as calibrations for the molecular clock, and investigate the timing of Pycnogonida evolution. This can help them understand, for example, how their diversity was impacted by the different biodiversity crises that distributes over the Earth history.

    They also plan to investigate other pycnogonid fossil faunae such as the fauna of Hunsrück Slate, in Germany, which dates from the Devonian, some 400 million years ago.

    With the same approach, they will aim to redescribe these species and understand their affinities with extant species; and finally, to replace in the tree of life of Pycnogonida all the pycnogonid fossils from all periods.

    Dr Sabroux added: “These fossils give us an insight of sea spiders living 160 million years ago.

    “This is very exciting when you have been working on the living pycnogonids for years.

    “It is fascinating how these pycnogonids look both very familiar, and very exotic. Familiar, because you can definitely recognize some of the families that still exist today, and exotic because of small differences like the size of the legs, the length of the body, and some other morphological characteristics that you do not find in modern species.

    “Now we look forward to the next fossil discoveries – from the Jurassic and other geological periods – so that we can complete the picture!”

     

    Paper:

    ‘New insights into the sea spider fauna (Arthropoda: Pycnogonida) of La Voulte-sur-Rhône, France (Jurassic: Callovian)’ by Romain Sabroux et al in Papers in Palaeontology.

    University of Bristol

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  • Subaquatic Molecular Exchange

    Subaquatic Molecular Exchange

    Newswise — Corals and anemones engage in symbiotic relationships with algae and swap nutrients with them. A new study shows how this partnership is regulated at cell level.

    “Eat or be eaten” is not always the way things are in nature. It can be beneficial for different species to team up and pool their capabilities. Cnidarians such as corals and anemones were already committing to this kind of biological joint venture with algae from the dinoflagellate group 250 million years ago. Thanks to these symbioses, both sides are able to flourish in nutrient-poor waters where, in isolation, neither would stand a chance of surviving. Corals can thus lay the structural foundation for the most biodiverse of all marine ecosystems. They protect their dinoflagellate symbionts from predators and supply them with inorganic nutrients such as nitrogen and phosphorus. Conversely, the algae provide the coral with the products of their photosynthesis: carbohydrates, protein and fat.

    Yet this happy marriage can only work if the ‘barter’ arrangement is precisely regulated. And although a successful exchange of nutrients is critical to the health of the corals and, hence, to the whole of the coral reef ecosystem, the molecular mechanisms that regulate communication within this partnership are still largely unknown. A new study in Current Biology now shows that a signal path from way back in the evolutionary process plays a crucial role in the ‘trade’ that takes place between algae and coral.

    Eaten but not digested

    “Most types of coral have to absorb new dinoflagellate symbionts from their environment in each new generation,” explains LMU biologist Professor Annika Guse, lead author of the new study. The symbionts are initially absorbed like food into the coral’s digestive cavity and from there into the host’s cells. During this process, a kind of bubble known as the symbiosome forms around the algae. The symbiosome is chemically similar to a lysosome – another cell organelle that plays a pivotal role in digestion. “The difference to the lysosome is that, in the symbiosome, the dinoflagellates remain intact,” Guse notes. In effect, the host eats its symbionts without digesting them. “We do not yet know exactly how the algae survive this process.” Inside the symbiosome, the algae then continue to photosynthesize and produce nutrients that they share with their host. All nutrients and communication processes between the partners must therefore penetrate the shell of the symbiosome, which is made up of membranes from both host and symbiont.

    A ‘cell tax’ between symbiont and host

    To do all this, the symbiotic partners evidently use a signal path known as the mechanistic target of rapamycin (mTOR), which regulates cellular metabolism in all eukaryotes as a function of environmental factors such as the availability of nutrients. It has already been proven for other species that mTOR is also used for nutritional symbioses: “Various insect hosts use mTOR signal transmission for their bacterial endosymbionts,” Guse says. “Evidence of the same path has also been found for legumes and their fungal partners.” The researchers therefore suspected that mTOR could also be involved in the partnership between cnidarians and dinoflagellates. “We have been able to prove that endosymbiontic corals use the mTOR signal path to incorporate nutrients from the symbionts in the host metabolism.” All the vital components of mTOR exist in both anemones and corals. Annika Guse and her colleagues investigated the extent to which this signal path is activated by the presence of algae partners from the Symbiodiniaceae family at different developmental stages in anemones of the genus Aiptasia. They also tested how inhibiting mTOR signal transmission affected the symbiotic function. “Our findings show that mTOR signal transmission is activated by the symbiosis, and that disruptions to the signal path impair symbiosis at both the cellular and the organismic level,” Guse explains. “With the aid of a specific antibody, we were also able to show that mTOR is localized on the membranes of the symbiosome.”

    Repurposing an age-old signal path

    Studying their findings, the biologists conclude that mTOR is of tremendous importance to the incorporation of nutrients in the host’s metabolism and to the stability of the symbiosis. Given that much of the energy consumed by symbiotic cnidarians comes from their symbiotic partners, it is plausible that the highly conserved mTOR signal path has ultimately been used for efficient nutrient sensing within the framework of symbiosis. Accordingly, Guse and her team propose a model in which the nutrients released by the algae activate mTOR signal transmission in the symbiosome and in the host tissue – similar to the sensing of nutrients from external sources.

    The activation of mTOR signal transmission was probably also an important step in the evolution of this symbiosis, allowing the algae to survive within the host cells. “The mTOR activity controls what is called autophagy, a very ancient immune reaction on the evolutionary scale that is triggered when pathogens penetrate the host and that leads to the destruction of the intruder,” the biologist explains. This, she believes, is the reason why some pathogens – and the bacterial endosymbionts of some insects, too – have developed mechanisms to bypass autophagic elimination. Early symbionts could have been ingested by a cnidarian and absorbed into its cells. Instead of being ejected or destroyed, however, they were retained as they supplied the host cell with nutrients, activating the mTOR signals and thereby stopping the process of autophagy. “We are only now beginning to understand how the complex interaction between host and algae works and was able to develop over a million years of co-evolution,” Guse says.

    https://www.lmu.de/en/newsroom/news-overview/news/underwater-molecular-barter.html

    Ludwig-Maximilians-Universitat Munchen (Munich)

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  • Subaquatic Molecular Exchange

    Subaquatic Molecular Exchange

    Newswise — “Eat or be eaten” is not always the way things are in nature. It can be beneficial for different species to team up and pool their capabilities. Cnidarians such as corals and anemones were already committing to this kind of biological joint venture with algae from the dinoflagellate group 250 million years ago. Thanks to these symbioses, both sides are able to flourish in nutrient-poor waters where, in isolation, neither would stand a chance of surviving. Corals can thus lay the structural foundation for the most biodiverse of all marine ecosystems. They protect their dinoflagellate symbionts from predators and supply them with inorganic nutrients such as nitrogen and phosphorus. Conversely, the algae provide the coral with the products of their photosynthesis: carbohydrates, protein and fat.

    Yet this happy marriage can only work if the ‘barter’ arrangement is precisely regulated. And although a successful exchange of nutrients is critical to the health of the corals and, hence, to the whole of the coral reef ecosystem, the molecular mechanisms that regulate communication within this partnership are still largely unknown. A new study in Current Biology now shows that a signal path from way back in the evolutionary process plays a crucial role in the ‘trade’ that takes place between algae and coral.

    Eaten but not digested

    “Most types of coral have to absorb new dinoflagellate symbionts from their environment in each new generation,” explains LMU biologist Professor Annika Guse, lead author of the new study. The symbionts are initially absorbed like food into the coral’s digestive cavity and from there into the host’s cells. During this process, a kind of bubble known as the symbiosome forms around the algae. The symbiosome is chemically similar to a lysosome – another cell organelle that plays a pivotal role in digestion. “The difference to the lysosome is that, in the symbiosome, the dinoflagellates remain intact,” Guse notes. In effect, the host eats its symbionts without digesting them. “We do not yet know exactly how the algae survive this process.” Inside the symbiosome, the algae then continue to photosynthesize and produce nutrients that they share with their host. All nutrients and communication processes between the partners must therefore penetrate the shell of the symbiosome, which is made up of membranes from both host and symbiont.

    A ‘cell tax’ between symbiont and host

    To do all this, the symbiotic partners evidently use a signal path known as the mechanistic target of rapamycin (mTOR), which regulates cellular metabolism in all eukaryotes as a function of environmental factors such as the availability of nutrients. It has already been proven for other species that mTOR is also used for nutritional symbioses: “Various insect hosts use mTOR signal transmission for their bacterial endosymbionts,” Guse says. “Evidence of the same path has also been found for legumes and their fungal partners.” The researchers therefore suspected that mTOR could also be involved in the partnership between cnidarians and dinoflagellates. “We have been able to prove that endosymbiontic corals use the mTOR signal path to incorporate nutrients from the symbionts in the host metabolism.” All the vital components of mTOR exist in both anemones and corals. Annika Guse and her colleagues investigated the extent to which this signal path is activated by the presence of algae partners from the Symbiodiniaceae family at different developmental stages in anemones of the genus Aiptasia. They also tested how inhibiting mTOR signal transmission affected the symbiotic function. “Our findings show that mTOR signal transmission is activated by the symbiosis, and that disruptions to the signal path impair symbiosis at both the cellular and the organismic level,” Guse explains. “With the aid of a specific antibody, we were also able to show that mTOR is localized on the membranes of the symbiosome.”

    Repurposing an age-old signal path

    Studying their findings, the biologists conclude that mTOR is of tremendous importance to the incorporation of nutrients in the host’s metabolism and to the stability of the symbiosis. Given that much of the energy consumed by symbiotic cnidarians comes from their symbiotic partners, it is plausible that the highly conserved mTOR signal path has ultimately been used for efficient nutrient sensing within the framework of symbiosis. Accordingly, Guse and her team propose a model in which the nutrients released by the algae activate mTOR signal transmission in the symbiosome and in the host tissue – similar to the sensing of nutrients from external sources.

    The activation of mTOR signal transmission was probably also an important step in the evolution of this symbiosis, allowing the algae to survive within the host cells. “The mTOR activity controls what is called autophagy, a very ancient immune reaction on the evolutionary scale that is triggered when pathogens penetrate the host and that leads to the destruction of the intruder,” the biologist explains. This, she believes, is the reason why some pathogens – and the bacterial endosymbionts of some insects, too – have developed mechanisms to bypass autophagic elimination. Early symbionts could have been ingested by a cnidarian and absorbed into its cells. Instead of being ejected or destroyed, however, they were retained as they supplied the host cell with nutrients, activating the mTOR signals and thereby stopping the process of autophagy. “We are only now beginning to understand how the complex interaction between host and algae works and was able to develop over a million years of co-evolution,” Guse says.

    Ludwig-Maximilians-Universitat Munchen (Munich)

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  • Even treated wastewater affects our rivers

    Even treated wastewater affects our rivers

    Newswise — Effluents from wastewater treatment plants have a dual effect: Some species disappear, while others benefit. Especially certain insect orders, such as stonefly and caddisfly larvae, are decimated. Certain worms and crustaceans, by contrast, can increase in number. A team from Goethe University Frankfurt led by Daniel Enns and Dr. Jonas Jourdan has corroborated this in a comprehensive study, which has now been published in the journal Water Research. They examined 170 wastewater treatment plants in Hesse in relation to species composition.

    Wastewater treatment plants are an indispensable part of our modern infrastructure; they have made a significant contribution to improving the quality of our surface waters. However, their ability to completely remove what are known as micropollutants from wastewater is mostly limited. These substances include, for example, active ingredients from pharmaceuticals and personal care products, pesticides and other synthetic substances enter waterbodies via the treated wastewater, placing an additional burden on rivers and streams. This exacerbates the challenges faced by already vulnerable insect communities and aquatic fauna. Previous studies – which have primarily focused on single wastewater treatment plants – have already shown that invertebrate communities downstream of such effluents are generally dominated by pollution-tolerant taxa.

    Until now, however, it was unclear how ubiquitous these changes are. That is why a team of biologists from Goethe University Frankfurt has now studied extensively how wastewater from 170 wastewater treatment plants in Hesse has an impact on the species composition of invertebrates. This has prompted a change in the common conception that human-induced stressors reduce the number of species in a habitat and thus their diversity: Rather, the findings indicate that a shift in species composition can be observed. The researchers were able to identify significant shifts in the composition of the species community between sites located upstream and downstream of wastewater treatment plants. Some species were particularly affected by effluents from wastewater treatment plants – such as stonefly and caddisfly larvae, which disappear entirely in some places. Other taxa, such as certain worms and crustaceans, by contrast, benefit and are found in greater numbers. This change can be observed especially in streams and smaller rivers. Overall, wastewater treatment plants alter conditions downstream to the advantage of pollution-tolerant taxa and to the disadvantage of sensitive ones.

    How can we reduce water pollution?

    Modern treatment techniques such as ozonation or activated charcoal filtering can make water treatment in wastewater treatment plants more efficient, allowing a wider range of pollutants, including many trace substances, to be removed from the wastewater before it is released into the environment. Merging smaller wastewater treatment plants can also contribute to reducing the burden on the environment. Whatever measures are taken, it is important to make sure that upstream sections are not already degraded and are in a good chemical and structural condition.

     

    Publication: Enns D, Cunze S, Baker NJ, Oehlmann J, Jourdan J (2023) Flushing away the future: The effects of wastewater treatment plants on aquatic invertebrates. Water Research, 120388. doi.org/10.1016/j.watres.2023.120388

     

    Picture download: https://www.uni-frankfurt.de/141365425

    Goethe University Frankfurt

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  • Study Exposes Ecological Threats of Small-Scale Fisheries in Thailand

    Study Exposes Ecological Threats of Small-Scale Fisheries in Thailand

    Newswise — Marine conservation experts have revealed the extent of marine megafauna catch by small-scale fisheries, in Thailand for the first time.

    The Newcastle University study provides the first-ever estimate of the annual catch of marine megafauna species, including rays, sharks, sea turtles, dolphins, and dugongs, in Thailand’s small-scale fisheries – those fisheries using small boats, low tech equipment and often haul their fishing gear by hand.

    Published in the journal Aquatic Conservation: Marine and Freshwater Research, the results show estimated annual catches of 5.6 million rays, 457 thousand sharks, 2.4 thousand sea turtles, 790 small cetaceans, and 72 dugongs in Thailand’s small-scale fisheries.

    “We collected data using questionnaire interviews with 535 fishers in 17 provinces along the Gulf of Thailand and the Andaman Sea coasts in 2016 and 2017. Our results show that gillnets, especially crab gillnets and shrimp trammel nets, were responsible for most of the catch, posing a significant threat to marine megafauna in Thailand” said Dr Thevarit Svarachorn, who conducted the study during his PhD research at Newcastle University.

    Many of the species caught in these fisheries, like butterfly rays, wedgefish, and reef sharks, are already threatened with extinction. “These are shallow water species. They are very exposed to small-scale fisheries pressure, which are likely key drivers of their extinction risk around the world.” said co-author Dr Andrew Temple, Global Postdoctoral Fellow at King Abdullah University of Science and Technology.

    Senior author, Professor Per Berggren, Professor of Marine Megafauna Conservation at Newcastle University School of Natural and Environmental Sciences, said: “The study highlights the urgent need for regulating gillnet fishing, especially crab gillnets, to protect threatened megafauna from disappearing. These species are crucial for maintaining the health and productivity of the marine ecosystem.

    “Alternative fishing gears such as traps and pots should be considered to target the desired species without harming marine megafauna. Collaboration between fishers, manufacturers, and fisheries managers, along with training on best practices for releasing caught megafauna, could further reduce by-catch mortality.”

    The authors also recommend using LED lights on gillnets, acoustic deterrent devices, bycatch reduction devices and turtle excluder devices to help prevent megafauna bycatch.

    Newcastle University

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  • Long-Term Study Discovers Nitrogen Fixation Hotspots in Atlantic Seaweed

    Long-Term Study Discovers Nitrogen Fixation Hotspots in Atlantic Seaweed

    Newswise — A new study by researchers at the University of North Carolina at Chapel Hill examined nitrogen fixation among diazotrophs—microorganisms that can convert nitrogen into usable form for other plants and animals—living among sargassum. Sargassum, a brown macroalgae in the seaweed family, floats on the surface of the open ocean and provides habitat for a colorful array of marine life such as small fish, brine shrimp and other microorganisms. Previous studies have overlooked diazotrophs associated with sargassum, which could mean a historical underestimation of nitrogen fixation in the Atlantic nitrogen budget. The study, published today in PLOS ONE, found that nitrogen fixation in sargassum communities was significant.

    “The findings of this study are exciting, especially given much of the recent news regarding sargassum is about the negative effects of its overgrowth in Florida and the Caribbean,” said Lindsay Dubbs, a research associate professor and director of the Outer Banks Field Site at the UNC Institute for the Environment and research associate at East Carolina University’s Coastal Studies Institute. “We were able to show sargassum’s role in nitrogen fixation as meaningful in supporting marine productivity.”

    Nitrogen is critical for life. Plants and animals need it for growth. More nitrogen in the ocean means greater biological productivity and growth. Sargassum mats provide an important habitat for organisms to perform nitrogen fixation, but few studies have measured it in sargassum communities.

    “Only four studies have been published detailing rates of nitrogen fixation by epiphytes on pelagic sargassum and none in over 30 years,” said Claire Johnson, a Ph.D. student in the Department of Earth, Marine, and Environmental Sciences in the UNC College of Arts and Sciences and a graduate research assistant at the Coastal Studies Institute. “It’s really exciting for us to be able to contribute this long-term dataset which provides an updated view of this process and, in doing so, will hopefully bring attention to something which has been overlooked for decades.”

    The team compared the nitrogen fixation rate with other marine sources, including commonly studied nitrogen fixing organisms such as planktonic diazotrophs and coastal epiphytes—plants that grow on other plants—and found the sargassum communities outpaced them—contributing significantly to the marine nitrogen cycle and potentially to sargassum blooms.

    Collecting this type of data can be difficult, but the team’s proximity to the Gulf Stream from their lab at the Coastal Studies Institute on East Carolina University’s Outer Banks campus on Roanoke Island made it possible for them to make day-long trips to collect samples seasonally and process them quickly. The team was able to collect whole fronds of the seaweed and process them with minimal handling, better keeping the microorganisms intact for the study. Each piece was carefully managed in large tubs at the laboratory, where they collected data on nitrogen fixation rates. The team collected samples over a six-year period.

    Sargassum is typically abundant in the Caribbean Sea, Gulf of Mexico, Gulf Stream and Sargasso Sea. The team’s work in North Carolina provides a comprehensive view of how nitrogen fixation rates vary over time, but understanding how they could vary across a wider geographic range could be a next step for further research.

    “This research is even more critical now given the sargassum blooms in the South Atlantic,” said Johnson. “If nitrogen is being fixed by epiphytes on sargassum in this population on a scale anywhere near what we are seeing here, it would almost certainly have a significant impact on the Atlantic marine nitrogen budget.”

    “There is so much to be learned about this plant, the other life that it supports, and the factors that contribute to it becoming a nuisance in some places. I am optimistic that our long-term dataset will continue to reveal new insights about its importance and complexity,” Dubbs added.

    University of North Carolina at Chapel Hill

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  • Biosurfactants: A Promising Environmentally-Friendly Approach to Combat Oil Spills

    Biosurfactants: A Promising Environmentally-Friendly Approach to Combat Oil Spills

    Newswise — Can biosurfactants increase microbiological oil degradation in North Sea seawater?  An international research team from the universities of Stuttgart und Tübingen, together with the China West Normal University and the University of Georgia, have been exploring this question and the results have revealed the potential for a more effective and environmentally friendly oil spill response.

    Oil leaks into the oceans are estimated at approximately 1500 million liters annually worldwide. This leads to globally significant environmental pollution, as oil contains hazardous compounds such as polycyclic aromatic hydrocarbons that can have toxic or mutagenic effects on organisms. Oil spills, particularly catastrophic ones resulting in the rapid release of large quantities of oil into the oceans, such as tanker accidents or incidents at oil drilling platforms like Deepwater Horizon in 2010, are especially devastating.

    In such oil spill incidents, large quantities of chemical dispersants, ranging in the millions of liters depending on the amount of oil, are routinely applied to dissolve oil slicks, prevent oil from reaching coastlines, and enhance oil dispersion in the water. The hope is that microbial oil degradation will be enhanced as a result. This is because special microorganisms that are widespread in nature can feed on crude oil components and break them down into harmless substances. This special ability of microbes naturally cleans oil-contaminated areas.

    “In a study from the USA published in 2015, we demonstrated that – contrary to expectation – chemical dispersants in deep-sea water from the Gulf of Mexico can slow down microbial oil degradation,” says Prof. Sara Kleindienst, who worked at the University of Tübingen until 2022 and now works at the University of Stuttgart. “Since then, the topic has been at the center of controversial discussions, and there is still no simple answer to how oil spills can be combated more effectively,” emphasizes Prof. Sara Kleindienst.

    In the search for more environmentally friendly methods for dealing with oil spills, biosurfactants could offer a promising alternative to chemical dispersants. Biosurfactants are produced by microorganisms and can increase the bioavailability of oil components. This can thus enhance microbial oil degradation, which is crucial for purification.

    Experiments with seawater from the North Sea
    An international research team led by environmental microbiologist Professor Sara Kleindienst, with geomicrobiologist Professor Andreas Kappler (University of Tübingen) and biogeochemist Professor Samantha Joye (University of Georgia), compared the effects of biosurfactants and chemical dispersants. In the laboratory at the University of Tübingen, the researchers simulated oil spill conditions. For their experiment, they took over 100 liters of surface water from the North Sea close to the island of Helgoland. The seawater was treated with either the biosurfactant rhamnolipid or a dispersant (either Corexit 9500 or Slickgone NS), both in the presence and absence of oil. The research team used radioactive markers to track the degradation of the oil by the microorganisms in detail. “Our investigations using radioactively labeled hydrocarbons or a radioactively labeled amino acid showed that the highest rates of microbial hydrocarbon oxidation and protein synthesis occurred in the oil microcosms treated with rhamnolipid,” says Prof. Lu Lu, who previously worked at the University of Tübingen and now works at the China West Normal University.

    The impact on the composition of microbial communities also differed significantly between the approaches using biosurfactants compared to chemical dispersants. “This result suggests that the use of biosurfactants may stimulate different microbial oil degraders, both in terms of growth and activity, which in turn can affect the cleanup process after oil spills,” says Prof. Lu Lu.

    “Our findings suggest that biosurfactants have great potential for use in future oil spills in the North Sea or similar nutrient-rich ocean habitats,” adds Prof. Sara Kleindienst. “A visionary continuation of our work would be the development of products based on biosurfactants that offer both effective and environmentally friendly approaches to combating oil spills.”

    University of Stuttgart

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  • Sea snake vision evolved to regain colour

    Sea snake vision evolved to regain colour

    Newswise — An international team of scientists examining the genetic history of sea snakes have found that the species has enhanced their colour vision in response to living in brighter and more colourful marine environments.

    “Our research has found that the annulated sea snake possesses four intact copies of the opsin gene SWS1,” said PhD candidate Isaac Rossetto, from the University of Adelaide’s School of Biological Sciences who led the study.

    “Two of these genes have the ancestral ultraviolet sensitivity, and two have evolved a new sensitivity to the longer wavelengths that dominate ocean habitats.

    “The earliest snakes lost much of their ability to see colour due to their dim-light burrowing lifestyle.

    “However, their sea snake descendants now occupy brighter and more spectrally complex marine environments. We believe that recent gene duplications have dramatically expanded the range of colours sea snakes can see.”

    The team examined published reference genomes to examine visual opsin genes across five ecologically distinct species of elapid snakes. They looked at the gene data of Hydrophis cyanocinctus, or the annulated sea snake, a species of venomous snake found in tropical and subtropical regions of Australia and Asia.

    The team included scientists from The University of Adelaide, The University of Plymouth and The Vietnamese Academy of Science and Technology. They published their findings in the journal Genome Biology and Evolution.

    Many animals have lost opsins throughout their genealogical history as they’ve adapted to new habitats, but it is very rare to see opsin gains.

    “Humans have a similarly expanded sensitivity to colours, while cats and dogs are partially colour-blind much like those early snakes,” said Mr Rossetto.

    “It’s quite unique and interesting that these snakes appear to be gaining and diversifying their opsins, when other land-to-sea transitioned animals have done the opposite.”

    “Basically, there’s only one other case within reptiles at all where we think this has happened.”

    Newly gained colour-vision opsins have also been recorded in the semi-aquatic Helicops snake.

    Evidence of colour vision in Hydrophis snakes was first published in 2020, but this new research shows it is the result of gene duplication rather than gene polymorphism. This means expanded colour vision is more common among the species than first thought.

    “With a polymorphism, it’s a bit of a lottery – only some individuals would have that extended colour sensitivity. But now we know that there are multiple gene copies which have diverged, so colour vision is expected to be seen in all members of these species,” said Mr Rossetto.

    University of Adelaide

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  • Sea ice melt, warming ocean temperatures and emergency response: Experts discuss the return of El Niño

    Sea ice melt, warming ocean temperatures and emergency response: Experts discuss the return of El Niño

    The University of Delaware boasts several experts who can talk about El Niño’s return and its wide-reaching impacts, from record-breaking temperatures to sea ice melt that has been shattering scientists’ expectations. 

    Wei-Jun Cai: Air-sea CO2 flux; carbon cycling in estuaries and coastal oceans; global changes; sensor development; acid-base and redox chemistry in aquatic environments.

    Andreas Muenchow: Polar oceanography; glacier-ocean interactions; Greenland.

    Xiao-Hai Yan: Known for using satellites in tracking the notorious weathermaker El Niño and in developing new techniques for monitoring global climate change and coastal responses.

    Mark Warner: Phytoplankton physiological ecology, reef coral physiology, algal-invertebrate symbioses, harmful algal blooms, climate change.

    Carlos Moffatt: Polar oceanography; glacier-ocean interactions; the dynamics of riverine outflows; physical-biological interactions in coastal regions.

    Tricia Wachtendorf: Can speak to the challenges for communities and emergency managers associated with unexpected conditions that may result from warming climates. 

    University of Delaware

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  • Warmer and murkier waters favour predators of guppies, study finds

    Warmer and murkier waters favour predators of guppies, study finds

    Newswise — Changes in water conditions interact to affect how Trinidadian guppies protect themselves from predators, scientists at the University of Bristol have discovered.

    Known stressors, such as increased temperature and reduced visibility, when combined, cause this fish to avoid a predator less, and importantly, form looser protective shoals.

    The findings, published today in the journal Proceedings of the Royal Society B, show guppies’ responses are more affected by the interaction of these stressors than if they acted independently.

    Natural habitats are facing mounting environmental challenges due to human activities such as land use changes, exploitation and climate change.

    Lead author Costanza Zanghi from Bristol’s School of Biological Sciences, explained: “Of all the possible environmental parameters that can stress a system, we decided to focus on increased temperature and water turbidity because previous research has shown that visual animals, like most fish, are greatly affected by them.

    “We know that warmer water affects fish swimming ability and hunger levels, and we also know that increased turbidity, such as haziness, can change how visual predators and prey interact with one another.

    “In this research we wanted to take these common stressors, which are known to be increasing in freshwater habitats globally, and see how visual fish would respond to one another when they are subject to these stressors at the same time.”

    “This is important and novel because sometimes, especially when multiple stressors modify similar behaviours in different ways, the overall outcome can be very different from what is shown by studies where only one stressor is tested. That’s because these stressors can interact in unpredictable ways.”

    The team observed the reciprocal responses between a predator and a shoal of prey under four treatments, optimal housing conditions (as a control), and in treatments where either temperature or cloudiness of water was increased. They were then tested with an interaction treatment where both temperature and turbidity were increased at the same time.

    This took several weeks of trials in the lab involving 36 predators and 288 prey fish. The animals were separated so they did not come to any harm.

    All the video recordings were then processed to obtain fine scale movements of all the fish so that the researchers could calculate the swimming speeds of all fish and how they related to one another: how close together the prey stayed and how far from the predator each prey tried to remain.

    Co-author Milly Munro, who joined the Ioannou Group specifically for this project said: “The opportunity to be involved in this study with the team was a great experience, and I am grateful having been awarded ASAB’s Undergraduate Scholarship funding. Designing and running the research alongside Costanza and the team was brilliant as my first academic research experience. I learnt a lot of valuable skills and insights into what it takes to produce and conduct a study of this kind, all I gained from this experience has truly aided me in current and future projects.”

    Zanghi said: “Incorporating multi-stressors in such experiments enhances the ecological relevance and applicability of findings.

    “In natural environments, organisms rarely experience isolated stressors but rather face complex combinations of stressors.

    “By investigating how organisms respond behaviourally to these realistic scenarios, the research becomes more applicable to conservation and management efforts.

    “It provides insights into how organisms may cope with and adapt to multiple stressors, aiding in the development of effective strategies for mitigating the negative impacts of environmental change.

    Now the team plan to test whether the decrease in anti-predator behaviour is as negative for the prey as it may seem and not a clever adaptation to allow prey fish to worry less about predators in an environment that keeps them safe. By using a wider range of predators, they will also investigate whether these changes can affect multiple species differently.

    Zanghi concluded: “This study is exciting as it introduces crucial ecological complexity in the context of predator-prey interactions.

    “By incorporating additional stressors and specifically testing the potential interactions between these factors, this study significantly contributes to our understanding of the dynamics between prey and their predators in a rapidly changing world.”

     

    Paper:

    Zanghi C, Munro M, Ioannou CC. 2023 ‘Temperature and turbidity interact synergistically to alter anti-predator behaviour in the Trinidadian guppy’ Proceedings of the Royal Society B 290: 20230961.

    University of Bristol

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  • Gadusol: Nature’s sunscreen

    Gadusol: Nature’s sunscreen

    Newswise — As outside activities become more popular with the changing seasons, people are looking to protect themselves from sunburns and melanomas, primarily using commercial sunscreens.

    However, humans aren’t the only species that have to worry about damage from exposure to the sun’s ultraviolet rays. Many creatures use sunscreen, just not the white lotions that humans are familiar with. Their sunblock is encoded in their DNA.

    For years, U biologist James Gagnon’s lab has studied gadusol, a chemical compound in fish, resulting in a new paper demonstrating how females excrete the compound on their eggs. The gadusol molecule was discovered in fish more than 40 years ago, and was originally thought to come from dietary sources. It has since been proven that gadusol is produced from metabolic pathways within the fish.

    With help from colleagues in the School of Biological Sciences and Department of Human Genetics,  doctoral student Marlen Rice is the lead author of the paper published this week. Gagnon, an assistant professor of biology who holds a prestigious Mario Cappecchi Endowed Chair, is listed as the senior author.

    Rice grew up on a farm an hour south of Salt Lake City and earned a degree in molecular biology at Utah State University.

    “The fun thing to me about biology is just the fact that [living] things are dynamic and they interact [with] their environment,” Rice said. “I like thinking about animals in relation to ecology.”

    He aspires to bridge the gap between the ecological and molecular fields. Rice’s lifelong passion for animals and his industry background inspired him to use laboratory tools to investigate ecological factors, starting with sunlight, which sustains all life, but also presents a danger.

    Ultraviolet exposure

    Nearly all life on Earth depends on the sun, whether it’s tapping its energy to produce food, or consuming other organisms. But exposure to ultraviolet radiation (UVR) comes at a cost. Wavelengths in UVB rays are especially dangerous, causing damage at a molecular level and leading to mutations in DNA. Excessive levels of UVR exposure can even kill cells, a process known as apoptosis, resulting in what we know as a sunburn. Even in the water, organisms are not safe because biologically harmful levels of UVB can penetrate more than 10 meters deep.

    Protection lies in sunscreens which absorb UV photons before they penetrate vulnerable cells and dissipate this absorbed energy as less harmful heat, according to Rice and Gagnon’s paper. They act as physical shields over precious genetic material in cells, preventing damage and mutations.

    Organisms across many habitats have developed adaptations, including nocturnal lifestyles and DNA repair mechanisms, to avoid and fix the harm associated with UV exposure. But some have evolved an ability to create their own chemical sunscreens.

    “Since sunlit habitats can have significantly nutritive advantages over dark environments and because no repair pathway is completely efficient, many organisms employ sunscreens to avoid UVR damage from occurring in the first place,” the paper said.

    Mutant zebrafish

    Initially, Rice considered melanin as the primary sunscreen in aquatic life.  Melanin is produced in melanophores that migrate to cover parts of the brain and body as fish embryos mature.

    To test this hypothesis, Rice altered the genotype in zebrafish to knock out the gene for melanin production.  He found that zebrafish embryos died from UVR exposure at the same rate, regardless of whether or not their genotype was altered. There must be something else protecting the embryos.

    Through CRISPR-Cas9 gene editing, Gagnon’s lab created gadusol-deficient mutant zebrafish to test whether gadusol provide UV protection. Zebrafish were chosen for these experiments because they inhabit sunlit waters, produce gadusol and are amenable to genetic manipulation.

    He determined that gadusol is provided for zebrafish embryos by the mother, is the most effective sunscreen over other methods of protection and is lost evolutionarily in fish species when their embryos are not exposed to sunlight.

    “Transparency as camouflage”

    To demonstrate gadusol’s importance to the survival of larval fish, Rice delivered precise doses of UVB to both the mutant and unaltered zebrafish embryos and measured the effect on swim bladder inflation. When exposed to the same dose, the gadusol-deficient mutant fish were all unable to inflate their swim bladders, indicating that the UV exposure had caused significant developmental defects.

    A Boston-based beauty company is now looking to synthesize gadusol to create sunscreens that would be safer for both humans and marine environments. For fish, gadusol offers advantages over other sunscreens due to its invisibility. “Transparency as camouflage,” the study said, “is a common trait in aquatic animals, especially in the open ocean where there is nothing to hide behind.”

    Melanin’s main drawback is it absorbs most wavelengths in the visible light spectrum as well as the UVB spectrum, so it is detectable by predators. Sunlight, meanwhile, is just one of many challenges that aquatic ecosystems pose to their inhabitants.

    “The environment that they evolved in, which is filled with sunlight and viruses and predators and temperature switches and all this crazy stuff that doesn’t happen in our fish facility,” Gagnon said, “and so if you can bring a little bit of that into our laboratory, now we can apply what’s cool to more questions.”

    These environmental factors will guide the lab’s research with zebrafish moving forward. Rice is also curious about the evolutionary history of gadusol itself.

    “I’d really like to fill out on the tree of life how widespread gadusol is,” Rice said. “At some point, land vertebrates stopped using gadusol. I think evolutionarily it’d be really interesting to think about that. At what point did they move away?”

    The answers to these mysteries lie within—within DNA to be specific.

    “I really do love the idea of DNA. I think it’s a really beautiful thing,” Rice said, “the fact that it’s an unbroken chain of DNA replication and now lives inside of you.”

    The paper, titled “Gadusol is a maternally provided sunscreen that protects fish embryos from DNA damage,”  was published June 26 in Current Biology. It was funded with a grant from the National Institutes of Health. Other authors include Jordan Little and Julane Muchado, School of Biological Sciences, and Nathan Clark and Jordan Little with the U’s Department of Human Genetics.

     

    University of Utah

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  • Study estimates that gray whales near Oregon Coast ingest millions of tiny particles daily through their diet and feces.

    Study estimates that gray whales near Oregon Coast ingest millions of tiny particles daily through their diet and feces.

    Newswise — CORVALLIS, Ore. – Oregon State University researchers estimate that gray whales feeding off the Oregon Coast consume up to 21 million microparticles per day, a finding informed in part by poop from the whales.

    Microparticle pollution includes microplastics and other human-sourced materials, including fibers from clothing. The finding, just published in the journal Frontiers in Marine Science, is important because these particles are increasing exponentially and predicted to continue doing so in the coming decades, according to researchers Leigh Torres and Susanne Brander.

    Microparticle pollution is a threat to the health of gray whales, in addition to obstacles related to increased boat traffic and loss of prey.

    “These are quite scary numbers,” said Leigh Torres, an associate professor at Oregon State and an author of the paper. “I think they should raise concern for people who care about the marine environment or about their own environment and exposure to microplastics.

    “Little by little we are all getting exposed to more and more microplastics. That’s inescapable at this point across all ecosystems, including right off our coast here in Oregon.”

    Susanne Brander, an associate professor and ecotoxicologist at Oregon State and co-author of the study, said the findings reinforce the need to curb the release of microparticles because of the adverse impacts they have on organisms and ecosystems.

    “This issue is gaining momentum globally and some states, such as California, have taken important steps,” Brander said. “But more action needs to be taken, including here in Oregon, because this problem is not going away anytime soon.”

    The study focused on a subgroup of about 230 gray whales known as the Pacific Coast Feeding Group. They spend winters in Baja California, Mexico and migrate north to forage in coastal habitats from northern California to southern British Columbia from June through November.

    Since 2015, Torres, who leads the Geospatial Ecology of Marine Megafauna Laboratory in the OSU Marine Mammal Institute, and her team, including doctoral student Lisa Hildebrand, have used drones and other tools to study the health and behavior of this subgroup of gray whales off the Oregon Coast. As part of this work, they collect poop samples from the gray whales.

    For the new study, the researchers collected zooplankton, which are an important food supply for gray whales, and commercial and recreational fish.

     

    “We had determined the caloric content of several zooplankton species, so next we wanted to know what their microparticle loads might be to get a more complete picture of the quality of these prey items,” Hildebrand said.

    Brander, Hildebrand and members of Brander’s Ecotoxicology and Environmental Stress Lab analyzed the microparticle loads in 26 zooplankton samples collected from whale feeding areas and found microparticles in all of them. A total of 418 suspected microparticles were identified, with fibers accounting for more than 50% of them.

    Torres and Hildebrand then combined that data with known estimates of energetic requirements for lactating and pregnant female gray whales to quantify how many zooplankton and microparticles they consume in a day. That yielded estimates that lactating and pregnant whales consume between 6.5 million and 21 million microparticles per day.

    “It’s a wake-up call that whales are getting that much microplastic from what they eat,” Torres said. “It’s likely that humans are also getting a lot of microplastics from our own fish diet.”

    Torres notes that the microparticle consumption estimates are likely conservative because they only account for what the whales consume from zooplankton.

    Gray whales likely ingest more microparticles directly from the water and seafloor sediment because they are filter feeders that engulf large amounts of water while consuming prey and also use suction feeding to obtain prey from the seafloor.

    Analysis of the poop samples provided a window to what kind of microparticles these gray whales were digesting. The researchers analyzed five poop samples and found microparticles in all of them. Similar to zooplankton, the majority of the microparticles were fiber.

    The researchers also found that the microparticles in the poop were significantly larger than those found in the zooplankton, leading them to believe the larger particles came from the water or sediment, not the prey (too small to consume these larger particles).

    The findings raise concerns for Torres, whose past research has shown that this subgroup of gray whales is skinnier than other groups of gray whales.

    “These whales are already stressed out with boats driving around all the time and the risk of getting hit by one of those boats,” she said. “They might also have less prey around because of changes in the environment, like less kelp. And now the quality of the prey might be poor because of these high microplastic loads.”

    Brander and Torres are continuing their investigations by studying the effects of microfibers on zooplankton that are an important food source for whales and fish in Oregon waters.

    “That all can lead to being poorly nourished and having poor health,” Torres said, “That can lead to stunted growth, smaller body size, lower ability to have calves and animals not using this habitat anymore. All of those are areas of significant concern.”

    Other authors of the paper are Julia Parker, Elissa Bloom, Robyn Norman, Jennifer Van Brocklin and Katherine Lasdin. They are all from Oregon State and in the colleges of Agricultural Sciences, Engineering and Science. Brander is also affiliated with Oregon State’s Coastal Oregon Marine Experiment Station at the Hatfield Marine Science Center in Newport.

    Oregon State University

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  • New Early Toothed Whale Species Found

    New Early Toothed Whale Species Found

    Newswise — Have you ever wondered what the earliest ancestors of today’s dolphins looked like? Then look no further, meet Olympicetus thalassodon, a new species of early odontocete, or toothed whale, that swam along the North Pacific coastline around 28 million years ago. This new species is one of several that are helping us understand the early history and diversification of modern dolphins, porpoises and other toothed whales. The new species is described in a new study published in the open access journal PeerJ Life and Environment by Puerto Rican paleontologist Jorge Velez-Juarbe of the Natural History Museum of Los Angeles County.

    “Olympicetus thalassodon and its close relatives show a combination of features that truly sets them apart from any other group of toothed whales. Some of these characteristics, like the multi-cusped teeth, symmetric skulls, and forward position of the nostrils makes them look more like an intermediate between archaic whales and the dolphins we are more familiar with,” says Dr. Velez-Juarbe, Associate Curator of Marine Mammals at NHMLAC. 

    But Olympicetus thalassodon was not alone, the remains of two other closely related odontocetes were described in the same paper. The fossils were all collected from a geologic unit called the Pysht Formation, exposed along the coast of the Olympic Peninsula in Washington State and dated to between 26.5–30.5 million years. 

    The study further revealed that Olympicetus and its close kin belonged to a family called Simocetidae, a group so far known only from the North Pacific and one of the earliest diverging groups of toothed whales. Simocetids formed part of an unusual fauna represented by fossils found in the Pysht Formation and which included plotopterids (an extinct group of flightless, penguin-like birds), the bizarre desmostylians, early relatives of seals and walruses, and toothed baleen whales.

    Differences in body size, teeth and other feeding-related structures suggest that simocetids showed different forms of prey acquisition and likely prey preferences. “The teeth of Olympicetus are truly weird, they are what we refer to as heterodont, meaning that they show differences along the toothrow”, notes Dr. Velez-Juarbe, “this stands out against the teeth of more advanced odontocetes whose teeth are simpler and tend to look nearly the same.”

    However, other aspects of the biology of these early toothed whales remain to be elucidated, such as whether they could echolocate like their living relatives, or not. Some aspects of their skull can be related to the presence of echolocating-related structures, such as a melon. An earlier study had suggested that neonatal individuals could not hear ultrasonic sounds, so the next step would be to investigate the earbones of subadult and adult individuals to test whether this changed as they grew older.  

     

    PeerJ

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  • Large and In Charge

    Large and In Charge

    BYLINE: Kelly Craine

    Newswise — WACO, Texas (June 23, 2023) – Leopard seals are prehistoric, reptilian-looking marine predators often portrayed as scary villains in movies such as “Happy Feet” and “Eight Below,” but little is known about their basic biology. The combination of the extreme climate in Antarctica, the species’ solitary habits and their lethal reputation makes leopard seals one of the most difficult apex predators to study on Earth.

    In 2018 and 2019, Sarah Kienle, Ph.D., assistant professor of biology at Baylor University, and her colleagues collected movement and dive behavior data and samples from leopard seals off the Western Antarctic Peninsula. Their goal was to compile crucial baseline data on the ecology and physiology of this enigmatic species.

    Kienle and her colleagues published their first study on leopard seals in August 2022 in the journal Frontiers in Marine Science, in which they showed that leopard seals have flexible movement patterns and dive behaviors. This variability may offer leopard seals the resilience needed to survive the extreme climate and environmental disturbances occurring around Antarctica and beyond.

    Emily Sperou, a Ph.D. student at Baylor, is lead author of a new study examining the stress physiology of leopard seals.

    “Large and in charge: Cortisol levels vary with sex, diet and body mass in an Antarctic predator, the leopard seal” published this month in the journal Frontiers in Marine Science is the first in-depth study of leopard seal physiology.

    In this groundbreaking study, Sperou and colleagues, including Kienle, examined how cortisol – an important stress hormone – varies between leopard seals. Their study also shows that leopard seals have the highest cortisol concentrations of any pinniped, including seals, sea lions and walruses.

    ROLE OF CORTISOL

    As a stress hormone, cortisol is an essential biomarker in mammals that regulates physiological processes such as the immune system, reproductive function, and even behavior.

    Cortisol levels in mammals can fluctuate due to a wide variety of internal and external stressors ranging from the daily fight for survival to changes in diet. Sperou wanted to know how cortisol varied in leopard seals based on different ecological and life history traits, like sex, age, body size and diet.

     “Measuring and comparing cortisol concentrations provides important context for understanding the physiological responses of mammals,” Sperou said.

     THE STUDY

    The goals for this study were to establish baseline cortisol concentrations for leopard seals and assess how cortisol levels change among individual leopard seals within a single population. To do this, Sperou measured cortisol concentrations, body mass and diet from 19 leopard seals that were sampled in the 2018-2019 expedition.

    Prior to the latest Baylor research, only one previous study has been conducted on cortisol values in leopard seals. This earlier study only measured cortisol in four seals and did not include information on their sex or body size.  

    “The smaller your sample sizes and with no context for the animals, it’s hard to figure out what cortisol concentrations mean and how that compares to other individual seals and other species,” Kienle said.

    Sperou also compared the leopard seal cortisol levels to 26 other closely related carnivore species with comparable data, including pinnipeds, bears, badgers and otters.

    FINDINGS

     Leopard seals have extremely highest cortisol levels.

      • Leopard seals in this study have the highest cortisol levels ever reported for this species.
      • An adult male leopard seal now holds the record for the highest cortisol level in any pinniped and other closely related mammals.

     Leopard seal cortisol levels vary based on sex, body size and diet.

      • Females are significantly larger than males.
      • Females feed on higher energy level prey in the food chain than males.
      • Females have significantly lower cortisol concentrations than males.

     Leopard seals have cortisol values 1.25 to 50 times higher than closely related carnivores.

      • Leopard seals have higher cortisol levels than 26 other closely related mammal species, including seals, sea lions, walruses, bears, badgers and otters. OH MY!
      • Leopard seals, along with other Antarctic seals, have higher cortisol than other pinnipeds across the planet.
      • High cortisol may be a specialized adaptation within this group of Antarctic-living marine mammals.

     

    CONCLUSION

    Evaluating the physiology of leopard seals and how their physiology changes based on their life history and ecology provides critical information about the health of individual seals and their population. Leopard seals are one of the least studied apex predators on Earth but play a disproportionately large role in Antarctic ecosystem structure and function. 

    For Sperou, this groundbreaking study provides a strong foundation for assessing leopard seals’ physiology, which is fundamental for understanding their vulnerability to climate change.

    “It’s important we understand how these species are going to respond when their environment is rapidly changing,” Sperou said.

    What’s next for this team of leopard seal biologists?

    Kienle said the team is now focused on traveling to different areas around the southern hemisphere to sample leopard seals across their range. Her team will use these data to better examine their ecology and physiology at different scales – from individuals to populations to the entire species. Their ultimate goal is to understand the adaptive capacity of leopard seals and ensure the health and well-being of this amazing species now and in the future.

    ABOUT THE AUTHORS

    Sarah Kienle, Ph.D. is an assistant professor of biology at Baylor University and the principal investigator and director of the Comparative Animal Ecophysiology Lab (CEAL). Her research broadly focused on understanding how animals work in the context of their environment. 

    Emily Sperou,  Ph.D. candidate at Baylor University, is part of the research team at Dr. Kienle’ s Comparative Ecophysiology of Animals Lab (CEAL). She is broadly interested in investigating the links between organisms’ physiological systems to larger ecological processes.

    For her Ph.D. dissertation, Sperou is comparing intraspecific variation and behavioral flexibility in the ecology and physiology of leopard seals. This research will use a comparative approach to determine the relationships between behavioral patterns, life history traits, foraging ecology and physiological performance.

    In addition to Kienle and Sperou, the research team included:

     

    • Daniel E. Crocker, Department of Biology, Colorado State University, Fort Collins, CO
    • Renato Borras-Chavez, Department of Biology, Post Doctoral Research for the Comparative Animal Ecophysiology Lab at Baylor University, Waco, TX
    • Daniel P. Costa, Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA
    • Michael E. Goebel, Antarctic Ecosystem Research Division, Southwest Fisheries Science Center, National Oceanic and Atmospheric Administration (NOAA) Fisheries, La Jolla, CA, and Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA
    • Shane B. Kanatous, Department of Biology, Colorado State University, Fort Collins, CO
    • Stephen J. Trumble, Department of Biology, Baylor University, Waco, TX

     

    This work was funded by the National Science Foundation grant #1644256.

    COMPARATIVE ECOPHYSIOLOGY OF ANIMALS LAB

    The Comparative Ecophysiology of Animals Lab at Baylor University focuses on understanding how different animals work in the context of their environment. Researchers use quantitative analytical techniques to examine physiological and ecological factors that shape mammalian life history strategies. Research in this lab falls into three themes:

    • Characterizing relationship between animal form and function
    • Comparing trade-offs between different life history strategies
    • Examining flexibility in ecophysiological traits

    ABOUT BAYLOR UNIVERSITY

    Baylor University is a private Christian University and a nationally ranked Research 1 institution. The University provides a vibrant campus community for more than 20,000 students by blending interdisciplinary research with an international reputation for educational excellence and a faculty commitment to teaching and scholarship. Chartered in 1845 by the Republic of Texas through the efforts of Baptist pioneers, Baylor is the oldest continually operating University in Texas. Located in Waco, Baylor welcomes students from all 50 states and more than 90 countries to study a broad range of degrees among its 12 nationally recognized academic divisions.

    ABOUT THE COLLEGE OF ARTS & SCIENCES AT BAYLOR UNIVERSITY

    The College of Arts & Sciences is Baylor University’s largest academic division, consisting of 25 academic departments in the sciences, humanities, fine arts and social sciences, as well as 10 academic centers and institutes. The more than 5,000 courses taught in the College span topics from art and theatre to religion, philosophy, sociology and the natural sciences. Faculty conduct research around the world, and research on the undergraduate and graduate level is prevalent throughout all disciplines. Visit baylor.edu/artsandsciences.

     

     

     

    Baylor University

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  • Eddies: Impact on World’s Hottest Oceans

    Eddies: Impact on World’s Hottest Oceans

    Newswise — Water from the Pacific Ocean flows into the Indian Ocean via the Indonesia Archipelago Seas thanks to a vast network of currents dubbed the Indonesian Throughflow (ITF). The ITF acts as a heat and moisture conveyer belt, transporting warm and nutrient waters. Yet the ITF is neither a steady nor a straight path, but experiences fluctuations and turbulence as it passes through the various sea regions, straits, and passages.

    Currents can sometimes formulate into circular motions, forming a whirlpool-like phenomena. These are known as eddies, and they are prominent in areas where there are strong gradients in temperature, salinity, or velocity. Their rotating motion can cause nutrients from the colder, deeper waters to rise to the surface.

    To investigate the role eddies play in determining the path of the ITF, an international research group has harnessed a high-resolution ocean general circulation model that reproduces eddies. The group featured researchers from Tohoku University, JAMSTEC, Kyushu University, the University of Hawai`i at Mānoa, and the National Research and Innovation Agency of Indonesia.

    Details of their research were reported in the Journal of Geophysical Research – Oceans on May 14, 2023.

    The group’s model enabled them to calculate the transport of simulated particles in a daily-averaged flow field with eddies and a monthly-averaged flow field with smoothed eddy currents, respectively, and estimate the flow rate transported by the simulated particles.

    In the Sulawesi Sea, which is situated along the northeastern coast of Borneo and also borders the southern Filipino island of Mindanao, the Sulu archipelago, and Sulawesi Island’s western coast, the group found that large flow fluctuations occur, and seawater circulates over a wider area for an extended period. Seawater also rises from the middle to near the surface, which may cause significant changes in the water when flowing through due to turbulent mixing.
    On the eastern side of Sulawesi Island sits the Banda Sea, which surrounds the Maluku Islands and borders the islands of New Guinea and Timor. Here, the current fluctuation is slight, and the model predicted negligible influence from the eddies on the Indonesian Current.

    “Our results indicate that the path and residence time of the ITF, along with the mixing process of seawater, must be appropriately reproduced by an ocean general circulation model to gain further insights into and better predict sea surface temperature fluctuations in each region of the Indonesian Archipelago,” points out Toshio Suga, professor of physical oceanography at Tohoku University’s Graduate School of Science and co-author of the paper.

    Global warming’s progression is expected to change the ITF. Such changes could have profound repercussions for water temperatures in the Indonesia Archipelago and the Indian Ocean, El Niño and the Indian Ocean Dipole, and the frequency and scale of marine heatwaves that affect marine ecosystems and local weather. Therefore, it is vital to predict accurately such phenomena.

    Looking ahead, the group hopes to improve the accuracy of future predictions by clarifying the degree to which eddies impact the path and residence time of the ITF, something quantitatively linked to the determination of water temperature in these areas.

    Tohoku University

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  • Ancient viruses found in coral symbionts’ DNA

    Ancient viruses found in coral symbionts’ DNA

    Newswise — HOUSTON – (June 1, 2023) –A group of marine biologists from various countries has made a remarkable finding, uncovering the traces of ancient RNA viruses integrated into the DNA of symbiotic organisms residing within coral reefs.

    In a groundbreaking revelation, it has been revealed that the RNA fragments derived from viruses had infected the symbiotic organisms as far back as 160 million years. The astonishing discovery, highlighted in a recent open-access publication in the journal Communications Biology by Nature, holds immense potential for enhancing our understanding of the ongoing battle against viral infections in corals and their associated organisms. This finding has taken scientists by surprise since the integration of RNA viruses into the DNA of their host organisms is an uncommon phenomenon.

    Through the study, it has been revealed that endogenous viral elements (EVEs) are prevalent in the genetic makeup of coral symbionts. These symbionts, known as dinoflagellates, are single-celled algae residing within corals, imparting vibrant colors to their hosts. The identification of EVEs reinforces recent findings that viruses, not limited to retroviruses, have the ability to incorporate fragments of their genetic material into the genomes of their host organisms.

    “Then how did it happen?” inquired Adrienne Correa, one of the co-authors of the study from Rice University. She further explained, “While it might seem accidental, researchers are increasingly discovering that such occurrences are more common than previously thought. These ‘accidents’ have been identified in various hosts, ranging from bats and ants to plants and algae.”

    The presence of an RNA virus within coral symbionts came as an unexpected revelation.

    “I found this project particularly intriguing,” expressed Alex Veglia, the lead author of the study and a graduate student in Correa’s research team. Veglia continued, “Based on our current understanding, there is truly no logical explanation for the presence of this virus within the genome of the symbionts.”

    The research, funded by the Tara Ocean Foundation and the National Science Foundation, was spearheaded by Correa, Veglia, along with two scientists from Oregon State University: postdoctoral scholar Kalia Bistolas and marine ecologist Rebecca Vega Thurber. By unraveling crucial insights, this study offers valuable clues for scientists to enhance their comprehension of the ecological and economic ramifications of viruses on reef well-being.

    During their investigation, the researchers did not detect any endogenous viral elements (EVEs) derived from RNA viruses in the samples of filtered seawater or within the genomes of dinoflagellate-free stony corals, hydrocorals, or jellyfish. However, EVEs were found extensively in coral symbionts gathered from numerous coral reef locations. This indicates that the pathogenic viruses were, and likely still are, selective in their choice of target hosts.

    Correa, an assistant professor of biosciences, emphasized the vast diversity of viruses that exist on our planet. She explained, “While we have extensive knowledge about certain viruses, the majority of viruses remain uncharacterized. We may be able to detect their presence, but we are still unaware of their host organisms.”

    Correa highlighted the various methods by which viruses, including retroviruses, can replicate through host infections. She stated, “One intriguing aspect of our study is that this RNA virus is not classified as a retrovirus. Considering this, one wouldn’t anticipate it to integrate into the host’s DNA.”

    Correa remarked, “Over the past several years, we have observed a multitude of viruses within coral colonies, but it has been challenging to definitively determine their specific targets.” She further stated, “Therefore, this discovery provides us with the most reliable and conclusive data regarding the actual host of a virus associated with coral colonies. With this knowledge in hand, we can now delve into understanding why the symbiont retains that DNA or a portion of the genome. The question arises: Why hasn’t it been lost over time?”

    The revelation that the endogenous viral elements (EVEs) have been preserved over millions of years implies that they might hold some advantageous role for the coral symbionts. It also suggests the existence of a mechanism that actively promotes the genomic integration of EVEs.

    Veglia expressed the multitude of possibilities for further exploration, such as investigating whether these elements serve as antiviral mechanisms within dinoflagellates and assessing their potential impact on reef health, particularly in the context of rising ocean temperatures.

    Veglia raised important questions related to the potential influence of rising seawater temperatures on the presence of endogenous viral elements (EVEs) within Symbiodiniaceae species. He pondered whether the presence of EVEs in their genomes enhances their ability to combat infections caused by present-day RNA viruses. These queries emphasize the need for further research to unravel the intricate connections between EVEs, symbiont genomes, and the response to viral infections under changing environmental conditions.

    “In another study, we demonstrated that there is a rise in RNA viral infections during episodes of thermal stress in corals. Hence, there are numerous interconnected factors at play. The current discovery provides another valuable piece to complete the puzzle,” Veglia explained. The intricate relationship between thermal stress, viral infections, and coral health requires comprehensive examination to gain a holistic understanding of the dynamics involved.

    Correa cautioned against making assumptions about the virus having a negative impact, but she also noted that there is evidence suggesting its increased productivity under conditions of temperature stress. This highlights the complexity of the situation and the need for further investigation to better understand the potential effects of the virus on coral health.

    Thurber holds the distinguished position of Emile F. Pernot Professor in the Department of Microbiology at Oregon State University.

    The study included more than 20 co-authors from the University of Konstanz, Germany; the Institute of Microbiology and Swiss Institute of Bioinformatics, Zürich; the University of Perpignan, France; the Scientific Center of Monaco; the Université Paris-Saclay, Evry, France; the Tara Ocean Foundation, Paris; the University of Maine; Sorbonne University, France; the University of Tsukuba, Japan; Paris Science and Letters University, France; the University of Paris-Saclay; the Weizmann Institute of Science, Rehovot, Israel; Côte d’Azur University, Nice, France; the European Bioinformatics Institute, University of Cambridge, England; Ohio State University; and the National University of Ireland, Galway.

    National Science Foundation support was provided by three grants (2145472, 2025457, 1907184).

    -30-

    Peer-reviewed paper:

    “Endogenous viral elements reveal associations between a non-retroviral RNA virus and symbiotic dinoflagellate genomes” | Communications Biology | DOI: 10.1038/s42003-023-04917-9

    Authors: Alex J. Veglia, Kalia S.I. Bistolas, Christian R, Voolstra, Benjamin C. C. Hume, Hans-Joachim Ruscheweyh, Serge Planes, Denis Allemand, Emilie Boissin, Patrick Wincker, Julie Poulain, Clémentine Moulin, Guillaume Bourdin, Guillaume Iwankow, Sarah Romac, Sylvain Agostini, Bernard Banaigs, Emmanuel Boss, Chris Bowler, Colomban de Varga, Eric Douville, Michel Flores, Didier Forcioli, Paola Furla, Pierre Galand, Eric Gilson, Fabien Lombard, Stéphane Pesant, Stéphanie Reynaud, Matthew B. Sullivan, Shinichi Sunagawa, Olivier Thomas, Romain Troublé, Didier Zoccola, Adrienne M.S. Correa, and Rebecca L. Vega Thurber

    https://doi.org/10.1038/s42003-023-04917-9

     

     

    Rice University

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  • Time to ditch flaky white fish obsession

    Time to ditch flaky white fish obsession

    Newswise — New research highlights the implications for our future food security as the UK faces a growing disparity between the fish we catch and the fish we desire to consume.

    In a groundbreaking study published in the international peer-reviewed journal Reviews in Fish Biology and Fisheries, researchers from the University of Essex and the Centre for Environment Fisheries and Aquaculture Science (Cefas) present a thorough and extensive analysis. This study, spanning 120 years, provides valuable insights into the ways major policy shifts have shaped the landscape of seafood production, trade, and consumption in the UK.

    The study reveals that altering our preference for imported flaky white fish, such as cod and haddock, to species that are abundant in our local waters, like herring and mackerel, would not be sufficient to fulfill the UK’s domestic demand or align with the government’s guidelines for healthy eating. It emphasizes that even with such a change in fish consumption habits, UK seafood production would remain insufficient.

    Luke Harrison, the lead researcher from Essex’s School of Life Sciences, elaborated on the study, stating that their findings shed light on the impact of policy changes in the mid-1970s. Specifically, the establishment of Exclusive Economic Zones (EEZ) and the UK’s membership in the European Union contributed to a significant disparity between the seafood produced within the country and the seafood consumed domestically.

    The widening gap between seafood availability and consumption, which has been intensified by declining stocks due to fishing, climate change, and habitat degradation, surpasses any previous disparities observed, even during times of global conflict like the two world wars. This discrepancy has led to an escalating dependence on seafood imports and a decline in domestic catches.

    Fish has emerged as one of the highly traded food commodities globally, and the UK has witnessed a significant surge in seafood imports, a trend that was relatively minimal before the 1970s. Presently, the majority of fish consumed in the UK is imported, while a significant portion of the fish produced within the country is exported from both fisheries and aquaculture. The UK’s preference for large, flaky fish originated in the early 1900s when the nation enjoyed a prosperous distant-water fishery.

    Nevertheless, in present times, these desirable species are caught in limited quantities within UK waters. Conversely, abundant and cost-effective bony species, notably mackerel and herring, are caught in substantial quantities. However, instead of being primarily consumed domestically, these species are primarily exported to the Netherlands and France.

    Dr. Georg Engelhard, a co-author from Cefas, elaborated on the matter, emphasizing that the increasing popularity of tuna, shrimps, and prawns among UK consumers indicates a failure to adapt eating habits in response to the changing availability of local seafood over time. Despite notable shifts in the local seafood landscape, consumer preferences have remained largely unaltered.

    Following the establishment of Exclusive Economic Zones (EEZs) and the UK’s accession to the European Union in the mid-1970s, there has been a sharp decline in domestic landings of fish in the UK. The figures demonstrate a significant decrease, with landings plummeting from 869 thousand tonnes in 1975 to 349 thousand tonnes in 2020.

    Presently, the UK population consumes 31% less seafood than what is recommended by government guidelines. Even if local species were to become more popular, the combined production from domestic fisheries and aquaculture would still fall short by 73% of the recommended levels, even when accounting for imports.

    Dr. Anna Sturrock, the senior author from Essex’s School of Life Sciences, further commented, stating that in light of climate change, rampant overfishing worldwide, and potential trade barriers, it is crucial to promote locally sourced seafood and offer clearer guidance on non-seafood alternatives. By doing so, we can effectively address national food security concerns while also striving to achieve health and environmental objectives.

    University of Essex

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