It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
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.
NEWPORT, Ore. – Rates of Chinook salmon bycatch in the Pacific hake fishery rise during years when ocean temperatures are warmer, a signal that climate change and increased frequency of marine heatwaves could lead to higher bycatch rates, new research indicates.
During years when sea surface temperatures were higher, including during a marine heatwave, Chinook salmon were more likely to overlap with the Pacific hake and raise the risk of bycatch as they sought refuge from higher temperatures.
The findings, based on 20 years of bycatch data and ocean temperature records, provide new insight into the ecological mechanisms that underlie bycatch, which is the incidental capture of a non-targeted species, said the study’s lead author, Megan Sabal.
“The impact of ocean warming on bycatch has potential cultural, economic and ecological consequences, as the hake and salmon fisheries are each worth millions of dollars and salmon are critical to both Indigenous tribes’ cultural heritage and healthy ecosystems,” said Sabal, who worked on the project as a postdoctoral scholar at Oregon State University.
Pacific hake, also known as Pacific whiting, is the largest commercial fishery by tonnage on the U.S. West Coast. The rate is low but bycatch remains a concern for the Chinook salmon population, said Michael Banks, a marine fisheries genomics, conservation and behavior professor at Oregon State University and a co-author of the study.
“The hake fishing industry is very sensitive to the impacts of bycatch on salmon and has been diligent in reducing it, but changing climate conditions might become an increasing issue,” he said.
Pacific hake school in midwater depths off the West Coast from southern Baja California to the Gulf of Alaska. Hake is commonly used in surimi, a type of minced fish used to make imitation crab.
Most hake fishing occurs at depths of 200 to 300 meters and Chinook salmon typically occupy more shallow depths. If changing water temperature affects salmon distribution, that could increase salmon bycatch, the researchers noted.
“Developing a mechanistic understanding of how environmental conditions might impact bycatch can help us prepare for the future and think about how to adapt current strategies to keep up with a changing world,” said co-author Kate Richerson of the National Oceanic and Atmospheric Administration’s Northwest Fisheries Science Center Newport Research Station.
To better understand the impacts of changing ocean conditions, the researchers tapped into 20 years of data collected through NOAA’s At-Sea Hake Observer Program. Observers are placed aboard hake catcher-processor vessels and motherships that receive catch to process and record information about fishing depth and location, species composition and more.
Sabal and her coauthors modeled observer data and genetic stock identification to show salmon moving lower into the water column during higher temperatures.
“These behavioral changes can provide important information for researchers and can also inform creative conservation solutions,” Sabal said.
The researchers also found that limiting night fishing, a common mitigation strategy to reduce bycatch, will likely become less effective when sea surface temperatures are warmer near the surface.
The findings suggest that new strategies may be needed to continue mitigating bycatch in the hake fishery, Banks said. As technology improves, fishermen and fishery managers might be able to forecast bycatch impacts based on real-time ocean condition information and make adaptive management decisions about fishing strategy based on those conditions.
“As the oceans and the world are changing, the conflict between the two fisheries is showing up in new ways,” he said, “and we may need to shift strategies based on this understanding.”
Banks is affiliated with OSU’s Department of Fisheries, Wildlife, and Conservation Sciences in the College of Agricultural Sciences and the Coastal Oregon Marine Experiment Station at Hatfield Marine Science Center. Sabal was affiliated with the Cooperative Institute for Marine Ecosystems and Resources Studies and the Coastal Oregon Marine Experiment Station while working on the project and now works for the Oregon Department of Fish and Wildlife as a quantitative fisheries scientist.
Additional coauthors are Taal Levi of OSU’s College of Agricultural Sciences and Paul Moran and Vanessa Tuttle at NOAA’s Northwest Fisheries Science Center in Seattle.
IMAGE: TO TRACK THE CHANGES IN OCEAN COLOR, SCIENTISTS ANALYZED MEASUREMENTS OF OCEAN COLOR TAKEN BY THE MODERATE RESOLUTION IMAGING SPECTRORADIOMETER (MODIS) ABOARD THE AQUA SATELLITE, WHICH HAS BEEN MONITORING OCEAN COLOR FOR 21 YEARS.view more
CREDIT: NASA AND JOSHUA STEVENS, USING LANDSAT DATA FROM THE U.S. GEOLOGICAL SURVEY AND MODIS DATA FROM LANCE/EOSDIS RAPID RESPONSE.
CAMBRIDGE, MA -- The ocean’s color has changed significantly over the last 20 years, and the global trend is likely a consequence of human-induced climate change, report scientists at MIT, the National Oceanography Center in the U.K., and elsewhere.
In a study appearing today in Nature, the team writes that they have detected changes in ocean color over the past two decades that cannot be explained by natural, year-to-year variability alone. These color shifts, though subtle to the human eye, have occurred over 56 percent of the world’s oceans — an expanse that is larger than the total land area on Earth.
In particular, the researchers found that tropical ocean regions near the equator have become steadily greener over time. The shift in ocean color indicates that ecosystems within the surface ocean must also be changing, as the color of the ocean is a literal reflection of the organisms and materials in its waters.
At this point, the researchers cannot say how exactly marine ecosystems are changing to reflect the shifting color. But they are pretty sure of one thing: Human-induced climate change is likely the driver.
“I’ve been running simulations that have been telling me for years that these changes in ocean color are going to happen,” says study co-author Stephanie Dutkiewicz, senior research scientist in MIT’s Department of Earth, Atmospheric and Planetary Sciences and the Center for Global Change Science. “To actually see it happening for real is not surprising, but frightening. And these changes are consistent with man-induced changes to our climate.”
“This gives additional evidence of how human activities are affecting life on Earth over a huge spatial extent,” adds lead author B. B. Cael PhD ’19 of the National Oceanography Center in Southampton, U.K. “It’s another way that humans are affecting the biosphere.”
The study’s co-authors also include Stephanie Henson of the National Oceanography Center, Kelsey Bisson at Oregon State University, and Emmanuel Boss of the University of Maine.
Above the noise
The ocean’s color is a visual product of whatever lies within its upper layers. Generally, waters that are deep blue reflect very little life, whereas greener waters indicate the presence of ecosystems, and mainly phytoplankton — plant-like microbes that are abundant in upper ocean and that contain the green pigment chlorophyll. The pigment helps plankton harvest sunlight, which they use to capture carbon dioxide from the atmosphere and convert it into sugars.
Phytoplankton are the foundation of the marine food web that sustains progressively more complex organisms, on up to krill, fish, and seabirds and marine mammals. Phytoplankton are also a powerful muscle in the ocean’s ability to capture and store carbon dioxide. Scientists are therefore keen to monitor phytoplankton across the surface oceans and to see how these essential communities might respond to climate change. To do so, scientists have tracked changes in chlorophyll, based on the ratio of how much blue versus green light is reflected from the ocean surface, which can be monitored from space
But around a decade ago, Henson, who is a co-author of the current study, published a paper with others, which showed that, if scientists were tracking chlorophyll alone, it would take at least 30 years of continuous monitoring to detect any trend that was driven specifically by climate change. The reason, the team argued, was that the large, natural variations in chlorophyll from year to year would overwhelm any anthropogenic influence on chlorophyll concentrations. It would therefore take several decades to pick out a meaningful, climate-change-driven signal amid the normal noise.
In 2019, Dutkiewicz and her colleagues published a separate paper, showing through a new model that the natural variation in other ocean colors is much smaller compared to that of chlorophyll. Therefore, any signal of climate-change-driven changes should be easier to detect over the smaller, normal variations of other ocean colors. They predicted that such changes should be apparent within 20, rather than 30 years of monitoring.
“So I thought, doesn’t it make sense to look for a trend in all these other colors, rather than in chlorophyll alone?” Cael says. “It’s worth looking at the whole spectrum, rather than just trying to estimate one number from bits of the spectrum.”
The power of seven
In the current study, Cael and the team analyzed measurements of ocean color taken by the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard the Aqua satellite, which has been monitoring ocean color for 21 years. MODIS takes measurements in seven visible wavelengths, including the two colors researchers traditionally use to estimate chlorophyll.
The differences in color that the satellite picks up are too subtle for human eyes to differentiate. Much of the ocean appears blue to our eye, whereas the true color may contain a mix of subtler wavelengths, from blue to green and even red.
Cael carried out a statistical analysis using all seven ocean colors measured by the satellite from 2002 to 2022 together. He first looked at how much the seven colors changed from region to region during a given year, which gave him an idea of their natural variations. He then zoomed out to see how these annual variations in ocean color changed over a longer stretch of two decades. This analysis turned up a clear trend, above the normal year-to-year variability.
To see whether this trend is related to climate change, he then looked to Dutkiewicz’s model from 2019. This model simulated the Earth’s oceans under two scenarios: one with the addition of greenhouse gases, and the other without it. The greenhouse-gas model predicted that a significant trend should show up within 20 years and that this trend should cause changes to ocean color in about 50 percent of the world’s surface oceans — almost exactly what Cael found in his analysis of real-world satellite data.
“This suggests that the trends we observe are not a random variation in the Earth system,” Cael says. “This is consistent with anthropogenic climate change.”
The team’s results show that monitoring ocean colors beyond chlorophyll could give scientists a clearer, faster way to detect climate-change-driven changes to marine ecosystems.
“The color of the oceans has changed,” Dutkiewicz says. “And we can’t say how. But we can say that changes in color reflect changes in plankton communities, that will impact everything that feeds on plankton. It will also change how much the ocean will take up carbon, because different types of plankton have different abilities to do that. So, we hope people take this seriously. It’s not only models that are predicting these changes will happen. We can now see it happening, and the ocean is changing.”
IMAGE: ILLUSTRATION: MARE IMBRIUM TAKEN FROM APOLLO 17 IN 1972. LEFT OF CENTRE IS THE PYTHEAS CRATER. NEAR THE TOP IS THE COPERNICUS CRATER.view more
CREDIT: CREDIT NSSDC. FULL CREDIT INFO AT: HTTPS://NSSDC.GSFC.NASA.GOV/IMGCAT/HTML/OBJECT_PAGE/A17_M_2444.HTML
Scientists have ‘reset the clock’ for craters on the Moon, meaning that parts of its surface – which characterise the children’s story of the Man in the Moon - are around 200 million years older than had been thought.
Researchers from Norway and France have found a way of coordinating and recalibrating two conflicting systems of dating the surface of the Moon. This new evaluation shows that large parts of the crust of the Moon are around 200 million years older than had been thought and allows the scientists to clarify the sequence of events in the evolution of the Moon’s surface.
The Moon is now geologically pretty inactive, meaning that the craters from asteroids and comets which bombarded the Moon throughout time have not been eroded away; Earth has received a similar barrage throughout time, but the movements on the surface of the Earth will have masked these impacts.
Presenting* the work at the Goldschmidt Geochemistry Conference in Lyon, Professor Stephanie Werner (of the Centre for Planetary Habitability, University of Oslo) said:
“Looking at the signs of these impacts on the Moon shows what Earth would be like without the geological churning of plate tectonics which took place here on Earth. What we have done is to show that large portions of the lunar crust are around 200 million years older than had been thought”.
Researchers have known that the standard way of measuring the age of the surface of the Moon – a process known as crater counting – gave quite different results to that seen when examining rocks from the Apollo missions, especially for the light areas of the moon, the Highlands.
“We decided that we had to reconcile these differences, and that meant correlating individually dated Apollo samples to the number of craters in the sample site surrounding area – in effect, resetting the crater clock. We also correlated them against spectroscopy data from various Moon missions, especially the Indian Chandrayaan-1, to be sure which Apollo sample “belongs” to the surface in which we counted craters. This was a lot of work; we began this project in 2014. We found that by doing this we could resolve the discrepancy and push back the age of the surface of the Moon by up to 200 million years”.
As an example, the age of the Imbrium Basin, filled with the ‘lunar sea’, the Mare Imbrium (visible in the top left of the Moon), which was probably created by the collision of an asteroid impactor around the size of Sicily, goes back from 3.9 billion years ago, to 4.1 billion years ago. The researchers stress that this does not change the estimates of the Moon’s age itself, just the estimate of its surface. The new system of dating changes the age of all areas of the Moon’s surface - not uniformly, but with the oldest surfaces showing greatest changes.
Professor Werner said “This is an important difference. It allows is to push back in time an intense period of bombardment from space, which we now know took place before extensive volcanic activity that formed the “Man in the Moon” patterns - the mare volcanic plains including Mare Imbrium. As this happened on the Moon, the Earth was almost certain to have also suffered this earlier bombardment too”.
Prof. Audrey Bouvier (University of Bayreuth, Germany) commented “The Moon provides unique records of the early bombardment history. We have had three successful lunar sample return programs (Apollo, Luna, and Chang’e) which have associated rocks with their sampling locations on the Moon. By combining the latest spacecraft observations with impact events recorded by lunar rocks, Prof. Werner and her colleagues have greatly pushed back the records of heavy bombardment onto the terrestrial planets.
Such a heavy bombardment period must have affected the origin and early evolution of life on Earth and potentially other planets such as Mars. Bringing back rock samples from Jezero Crater on Mars will be the next giant leap forward to search for signs of ancient life on another planet in the Solar System, and when”.
This is an independent comment, Professor Bouvier was not involved in this work.
NOTES
Conference Abstract 15810 Lunar Time Travels – Introduction to a Revised Cratering Chronology Model Stephanie C Werner, Benjamin Bultel, Tobias Rolf
The work on which this presentation is based is in press at the peer reviewed publication The Planetary Science Journal:
Bultel, B. S.C. Werner (2023) Sample-Based Spectral Mapping Around Landing Sites on the Moon - Lunar Time Scale Part 1. The Planetary Science Journal, in press.
Werner, S.C., B. Bultel, T. Rolf (2023) Review and Revision of the Lunar Cratering Chronology - Lunar Time Scale Part 2. The Planetary Science Journal, in press.
The Goldschmidt Conference is the world’s main geochemistry conference. It is a joint congress of the European Association of Geochemistry and the Geochemical Society (US). It takes place in Lyon, France, from 9-14 July. Almost 5000 delegates are expected to attend. https://conf.goldschmidt.info/goldschmidt/2023/goldschmidt/2023/meetingapp.cgi
JOURNAL
The Planetary Science Journal
ARTICLE TITLE
(1) Sample-Based Spectral Mapping Around Landing Sites on the Moon - Lunar Time Scale Part 1 (2) ) Review and Revision of the Lunar Cratering Chronology - Lunar Time Scale Part 2.
Update 173 – IAEA Director General Statement on Situation in Ukraine
Vienna, Austria
International Atomic Energy Agency (IAEA) experts have in recent days continued to inspect parts of Ukraine’s Zaporizhzhya Nuclear Power Plant (ZNPP) – without seeing any mines or explosives – but are still waiting to gain the necessary access to the rooftops of reactor units 3 and 4 following recent reports that explosives may have been placed there, Director General Rafael Mariano Grossi said, adding that the nuclear safety and security situation remains very precarious.
The five basic principles that Director General Grossi established on 30 May at the United Nations Security Council state that there should be no attack from or against the plant and that it should not be used as storage or a base for heavy weapons – multiple rocket launchers, artillery systems and munitions, and tanks.
In recent days, the IAEA experts have heard a series of explosions apparently taking place some distance away from the ZNPP but still a stark reminder of potential nuclear safety and security risks facing the facility during the military conflict in the country.
One blast occurred in the morning of 8 July, several in the evening of 10 July, one yesterday morning and five in the evening. While it was not possible to determine the exact locations of the explosions, the IAEA experts were able to confirm that the site had not been impacted.
On 9 July, the IAEA team went to areas just inside the site perimeter and around the sprinkler cooling ponds. On 10 July, the experts went to the main control room, emergency control room, rooms where electrical cabinets of the safety systems are located and to the turbine hall of reactor unit 1, and today visited the corresponding areas in unit 3. Yesterday, the team also visited the unit 1 reactor hall, coolant pumps and safety system pumps. The experts reported that they had unrestricted access to these areas.
The IAEA continues to closely follow developments related to the availability of water for cooling the ZNPP’s six reactors and other essential nuclear safety and security functions, following the destruction of the downstream Kakhovka dam in early June and the subsequent depletion of the huge reservoir near the plant.
The IAEA team said the two main bodies of water – the ZNPP’s cooling pond and the discharge channel of the nearby Zaporizhzhya Thermal Power Plant (ZTPP) – had been relatively stable, with the water level decreasing by 1-2 centimetres per day due to usage and evaporation. The site continues to have sufficient water for some months.
As part of ongoing efforts to explore back-up options, the plant is planning to construct additional wells that could be used to replenish essential cooling water for the sprinkler ponds, which are currently utilizing underground water pumped from the site’s drainage system.
During the past week, a submersible pump was used to transfer some of the residual water in the ZTPP inlet channel into the ZTPP discharge channel, slightly increasing the height of the water in this channel.
The plant is separately preparing to move reactor unit 4 from cold shutdown to hot shutdown – after which unit 5, currently in hot shutdown, will be placed in cold shutdown in order to carry out preventive maintenance activities that are only possible in cold shutdown. The other units remain in cold shutdown.
The site uses the steam generated from one reactor unit in hot shutdown for various nuclear safety purposes including the processing of liquid radioactive waste collected in storage tanks. However, the IAEA experts are strongly encouraging the ZNPP to investigate all possible options to install an external boiler to generate the steam required, which would enable the site to bring all units into a cold shutdown state. The Ukraine national regulator – SNRIU – has issued regulatory orders to limit the operation of all six units to a cold shutdown state.
The IAEA is continuing to request the ZNPP to improve the conditions on site for Agency staff, including better accommodation, living and working conditions.
Since January this year, the IAEA also has a permanent presence at Ukraine’s other nuclear power plants – the Khmelnitsky (KhNPP), Rivne (RNPP), South Ukraine (SUNPP) and the Chornobyl (ChNPP) sites – where the most recent rotations of experts took place last week.
The IAEA teams report that the sites are continuing to maintain their operating and refuelling schedules despite the challenges faced by the conflict. They also confirm that there are no nuclear safety or security related issues at the four sites.
Among other activities, these IAEA experts help facilitate the delivery of assistance to Ukraine’s NPPs, organised by IAEA staff in Vienna, by discussing the technical specifications of safety and security equipment requested with their counterparts at the sites.
In the last two weeks, two deliveries of equipment to Ukraine took place, bringing the total to 21 since the conflict began in February 2022.
With the most recent deliveries, the KhNPP, SUNPP and RNPP received medical equipment and supplies that are essential for providing medical care and support, both to Ukrainian operating staff as well as to IAEA personnel at the sites.
In addition, the RNPP, SNRIU and State Enterprise Eastern Mining and Processing Plant, SE VostokGOK, received IT equipment, power supply systems, infrared sensors and portable tritium detectors. This equipment was procured with funds provided by Australia, the Republic of Korea and the United States of America as well as with support of the European Union.
Campaign aims to create "world’s largest library" of diverse medical illustrations
Chidiebere Ibe,whoseillustration of a Black fetus went viral a year and a half ago, is helping launch a campaign to diversify images used in medical textbooks and diagnosis manuals.
Studies have found about half of U.S. medical students learn visually, making illustrations a key component of their education.
Yet only 5% of medical images show dark skin, according to Illustrate Change, the new campaign aiming to create "the world's largest library of BIPOC medical illustrations."
Details: The campaign, a collaboration between Johnson & Johnson, the Association of Medical Illustrators (AMI) and Ibe, was announced late last month. It includes a fellowship program, a website with downloadable images and plans to promote the materials to medical schools.
The images feature dark-skinned people with lupus, cataracts, breast cancer and other ailments. They also include information on how communities of color are affected by a given disease or condition.
Jorge Leon, director of global community impact at Johnson & Johnson, says 10 illustrators will be chosen for a fellowship through the AMI and will receive training and a cash award.
The goal is for each fellow to create 10 illustrations featuring "additional communities and skin presentations" for the Illustrate Change library by the middle of next year.
What they're saying: Ibe tells Axios Latino that the viral image from 2021 challenged medical professionals "to reconsider their approach to health care by not dismissing patients who didn’t look like them."
The planned images can also help people when they search online for their symptoms, "ensuring that patients are involved in their own health care," Ibe says.
