Monday, December 20, 2021

Understanding the Big Bang and the Cosmological Lithium Problem

Cosmological Lithium Problem Evolution of the Universe

Figure 1. Artist’s representation of the evolution of the universe, with time flowing to the right in the direction of the red arrow. The 7Li(d,n)24He reaction takes place in the process of primordial nucleosynthesis at the very beginning. Credit: Modified version of NASA’s image by HOU Suqing

Recently, an international research team successfully updated the 7Li(d,n)24He reaction rate based on the latest experimental data, which removes the significant ambiguity in the cosmological lithium (Li) problem from the perspective of nuclear physics.

The Big Bang is currently regarded as the most successful model to describe the origination and evolution of the universe. However, its success has been limited by the so-called lithium problem, which refers to the fact that primordial lithium-7 abundance is overpredicted by a factor of three in comparison to the value from observation, while predictions match the observed primordial deuterium and helium abundances.

From the perspective of nuclear physics, the accurate reaction rates of lithium destruction reactions are very crucial for accurate prediction of the primordial lithium-7 abundance and further understanding of the lithium problem. Nevertheless, as an important lithium-7 destruction reaction, the 7Li(d,n)24He reaction has not been well studied before 2018.

A new study published in The Astrophysical Journal updated the 7Li(d,n)24He reaction rate based on the recent experimental measurements on the three near-threshold beryllium-9 excited states. This work was conducted by an international research team, which was led by HOU Suqing at the Institute of Modern Physics (IMP), Chinese Academy of Sciences (CAS).

Cosmological Lithium Problem Reaction Rate

Figure 2. Total reaction rate of 7Li(d,n)24He as a function of temperature in units of giga Kelvin where the green shaded band is its associated uncertainties. For comparison, researchers also plot the previous results from CF88 and BM93. Credit: Image by HOU Suqing

Researchers found that the new 7Li(d,n)24He rate is overall smaller than the previous estimation by about a factor of 60 at the typical temperature of the onset of primordial nucleosynthesis.

In addition, researchers presented uncertainties of the 7Li(d,n)24He reaction rate that are directly constrained by experiments for the first time.

According to the study, the new results remove the significant ambiguity in the calculated lithium-7 abundance due to this reaction, which will be useful to understand the primordial lithium problem and probe exotic physics beyond the standard model.

Reference: “New Thermonuclear Rate of 7Li(d,n)24He Relevant to the Cosmological Lithium Problem” by S. Q. Hou, T. Kajino, T. C. L. Trueman, M. Pignatari, Y. D. Luo and C. A. Bertulani, 25 October 2021, The Astrophysical Journal.
DOI: 10.3847/1538-4357/ac1a11

This work was supported by the Strategic Priority Research Program of CAS, the Youth Innovation Promotion Association of CAS and the National Natural Science Foundation of China.

Other institutions involved in the study include University of Tokyo (Japan), National Astronomical Observatory of Japan (Japan), Beihang University (China), the University of Hull (UK), Hungarian Academy of Sciences (Hungary), Michigan State University (US), and Texas A&M University- Commerce (US).


The Climate System Relies On Microscopic Particles

By Addrew Shawn 
On Dec 18, 2021
Credit: CC0 Public Domain

The Earth’s climate is an extremely complex system that is driven by the subtle balance of many different processes—a key one of which is the air-sea exchange of CO2. Monitoring the ocean’s uptake of CO2 is key to our understanding of climate change, and scientists at EPFL and at the Mediterranean Institute of Oceanography (MIO, France) have recently discovered a new part of the process. They identified a new source of organic phosphorus delivered from the atmosphere which potentially will help phytoplankton and microalgae growth, the latter of which play a crucial role in making our planet habitable. Organic phosphorus deposition to marine environments has not been studied till now, but this groundbreaking work showed it is an important—and completely overlooked—source of the critical nutrient, with important implications for climate. The scientists’ findings were recently published in the journal npj Climate and Atmospheric Science.

Phytoplankton, which live on the surface layers of lakes, seas and oceans, need a variety of chemical elements to grow, the main ones being iron, nitrogen and phosphorus. An abundance of these nutrients allow phytoplankton to bloom and carry out the critical function of photosynthesis, during which large amounts of CO2 is absorbed from the air and converted to biomass, while also releasing oxygen. That makes them highly important to living organisms and gives them a crucial role in regulating the Earth’s climate. Phytoplankton also form the base of the aquatic food chain, which sustains marine systems.

The supply and bioavailability of phosphorus affects the growth rate of phytoplankton, the rate at which they photosynthesize, hence the amount of CO2 they absorb. It is therefore important to identify all the ways in which marine ecosystems are fertilized; this can provide key insights into the climate system and how human activities affect it.

The full picture

“Scientists already knew that large amounts of inorganic phosphorus are transported to marine ecosystems by airborne dust in the form of phosphate minerals and ions. But this is an incomplete picture,” explains Kalliopi Violaki, the study’s lead author and a scientist at the Laboratory of atmospheric processes and their impacts (LAPI),which is part of EPFL’s School of Architecture, Civil and Environmental Engineering (ENAC).

Kalliopi Violaki organized and ran a two year-long research program at the MIO. During that time, she discovered that bioaerosols—airborne biological particles, such as viruses, bacteria, fungi, plant fibers and pollen—contain significant amounts of organic phosphorus. Although its exact amount is still uncertain, we know it is significant because it is comparable to the amount of inorganic phosphorus that dust aerosols supply. In addition, organic phosphorus is often found in the form of phospholipids, a key component of cell membranes.

“Being aware that terrestrial ecosystems can fertilize marine ecosystems via bioaerosols gives us a completely new perspective,” says Athanasios Nenes, head of LAPI and co-author of the study. “This knowledge will help us better understand the processes that influence the carbon cycle and the climate.”

A major discovery


Organic phosphorus has not yet been incorporated into climate models, but doing so could prove to be a major improvement to understand how marine ecosystems respond to the ongoing climate crisis. Ocean layers differ from one to another in terms of density, temperature, oxygen level and salinity, and climate change is inducing further changes. This makes mixing between the layers more difficult and disrupts CO2 absorption. As the ocean becomes more stratified, it also becomes harder for nutrients available in the deep sea to reach the various layers. This could adversely impact marine habitats and the food supply for many marine species, particularly in remote areas that have limited phosphorus supplies. The new source of phosphorous may completely change how the Mediterranean (and other) seas are predicted to respond to a changing climate.

This study shows how important are the atmospheric particles to the environment. Despite being microscopic in size, variations in their supply could cause major changes to the whole climate system. The scientists will therefore conduct further research in order to better understand this new source of organic phosphorus and how it might influence the Earth’s climate.

Cosmic dust may be key source of phosphorus for life on Earth

More information:

Kalliopi Violaki et al, Bioaerosols and dust are the dominant sources of organic P in atmospheric particles, npj Climate and Atmospheric Science (2021). DOI: 10.1038/s41612-021-00215-5

Provided by
Ecole Polytechnique Federale de Lausanne

Citation:
The climate system relies on microscopic particles (2021, December 17)
retrieved 17 December 2021
from https://phys.org/news/2021-12-climate-microscopic-particles.html

Ask a Caltech Expert: Professor Duo Discuss Connections Between Microbes and Climate 

Published on Saturday, December 18, 2021 

As part of Conversations on Sustainability, a webinar series hosted by the Caltech Science Exchange, Dianne Newman, Gordon M. Binder/Amgen Professor of Biology and Geobiology and Ecology and Biosphere Engineering Initiative Lead for the Resnick Sustainability Institute; and Victoria Orphan, James Irvine Professor of Environmental Science and Geobiology and Allen V. C. Davis and Lenabelle Davis Leadership Chair of the Center for Environmental Microbial Interactions; discussed their research into the connections between microorganisms and climate change.

Orphan and Newman explain how microbes have shaped Earth to allow for complex life such as plants and animals, how microorganisms are adapting to the warming planet, and how humans might be able to use these organisms to help address climate change.

Here, they talk with Caltech science writer Lori Dajose (BS ’15).

The questions and answers below have been edited for clarity and length.

How have microbes influenced the evolution of life on Earth, and how have they influenced the planet?

Orphan: Microbes represent the earliest forms of life on our planet, emerging some 3.8 billion years ago. Over these billions of years, they‘ve shaped the chemical and physical environment in which we live, and they’ve paved the way for the evolution of multicellular life, like plants and animals.

These microbes are the champions of ecosystem engineering. One poignant example I can give you is the invention of oxygen photosynthesis. The ability to use sunlight to split water is important not only in the production of oxygen, which we all depend upon, but also because microbes are able to fix carbon dioxide [i.e., convert CO2 from the air into organic material]. In turn, this changed the total amount of biomass that could be sustained on Earth. All these processes, as well as the nutrients that these organisms are collectively cycling through their microscale ecosystems, are truly influencing our planet. They’re really our lifeline in creating an environment that is habitable for us.

Can each of you tell me a little bit more about your research focus? What kind of microbes do you study, and why?

Newman: Many in the audience might be familiar with thinking about the microbiome with respect to human health. Microbes play an equally important role in planetary health, and they’ve been doing this for billions of years, like Victoria said. There are so many aspects of this, but the part that intrigues me are the strategies that microbes use to conserve energy. I love this as a general topic because it reaches into every facet of life on the planet, not only human life but also the life of plants and other organisms.

What I try to do in my research is pick bacteria to study that have metabolisms that are very fundamental, that are as relevant in the context of soil as they are in chronic infection.

I always am reminding myself and my students of the fact that at the microbial scale, the microbe only knows what’s in its immediate surroundings. It’s possible to utilize methods of modern genetics to pick organisms that are important environmental organisms but nevertheless ones that we can bring into the laboratory, cultivate, and come to learn how they catalyze these remarkable processes that change their environment in profound ways. Our goal is to understand how they do that so that we can predict, in diverse contexts, what they will be doing and ultimately gain the ability to manipulate and control them toward good ends.

Orphan: My main interest is in microorganisms that live in ocean ecosystems. The oceans represent 71 percent of our planet’s surface, and the microbes that live in that environment are critical for controlling Earth’s climate and sustainability on the planet. It’s really quite shocking, given how big this ecosystem is and the impact that it has, that so little of the ocean environment has been studied by scientists—somewhere on the order of 5 percent. There are wonderful opportunities for new discoveries of microorganisms and their activities that can have profound impacts.

A lot of our research is conducted in deep-ocean environments, looking at the roles that microorganisms play in the methane cycle. Like carbon dioxide [CO2], methane is another greenhouse gas that is dynamically changing over time, and the oceans are a huge reservoir for methane. A lot of this is in the form of ice-like material rimming the continents. It’s known as methane hydrate, and very little of this methane gets released into the atmosphere because microorganisms are oxidizing this gas in sediments, basically serving as a biological filter. These organisms have been very difficult to culture in the lab, and we use combinations of molecular techniques like genomic sequencing and geochemical and isotopic analyses to study these microorganisms directly in the environment.

When most people think of microbes, they might think of the germs that make us sick. Why is it important to study microbes in the context of the broader biosphere and planet?

Newman: Yes, it’s a common misconception to think of microbes as pathogens. I think that is a vestige of the last century, when a lot of microbiology was oriented toward understanding how pathogens work. What we now know is that of the millions of microbial species on the planet, less than 100 are thought to be hardcore pathogens. That means the vast majority are doing things that are vital for the life of the planet and its habitats.

Orphan: Only recently—I think in large part due to the recognition that the human microbiome is important for human health—has the public has gained a greater interest in microorganisms and recognized that they are more than just pathogens to be feared. The fact that they are hard to see, yet they’re so pervasive and have such a profound impact, is one of the biggest challenges for us in terms of communicating to the general public that everybody should be paying attention to the microbial world. Our ability to understand biology in general, I think, is integrated with our understanding of microorganisms, simply because we’ve evolved in a microbial world. They were here on the scene billions of years before us.

Newman: Plants and animals did not evolve in a sea of Purell, right? We were surrounded by the microbial world from the get-go.

We now are seeing the effects of anthropogenic climate change—for example, sea-level rise, hotter and dryer conditions in some places, and ocean acidification. How have microbes been affected? Is there a danger that certain microbes will become extinct?

Orphan: I talked about my research in the deep sea. More recently, we have been working on coastal vegetated ecosystems, which include marine plants like seagrass that are huge sequesters of carbon and are also thought to buffer against some of the effects of ocean acidification. There is a lot of research to be done studying the fate of carbon within these ecosystems. Microbes play a central role in how much carbon is buried and how the health of these ecosystems is sustained. Understanding this is important with increasing impacts of climate change and rising CO2 in the atmosphere.

Newman: Another example is that we now appreciate that there’s a large amount of carbon stored in soil, but we don’t understand very well the mechanisms that enable it. We know that it involves a complex interrelationship between certain types of microbes such as fungi, which are associated intimately with nearly all plants on Earth. These fungi help provide plants with nutrients and water that allow them to thrive. But within the soil, there are many other kinds of microbes in addition to the fungi that form a community that makes the entire ecosystem whole. And so, one of the main interests for microbial ecologists is gaining a predictive understanding of how these ecological systems will evolve in different parts of the world. In the northern latitudes, a lot of carbon is stored in the frozen tundra, but as the planet is warming, the carbon stored in that soil will not necessarily stay there. But we are unable to predict what will happen because we lack a quantitative understanding of which organisms are present in this habitat, what they’re doing, and how they’re going to respond.

I once heard somebody say, “Microbes were the first in and are going to be the last out,” in terms of the life on this planet. I think that’s very profound and important for us to realize because microbes are always adapting at a pace that’s extraordinary. That’s something that potentially, if we understand it, can be leveraged for the human population.

What are some concrete ways that microbes can help us address sustainability and climate change?

Newman: There are so many examples. I’ll stick with my agricultural theme to give one: The over-utilization of fertilizer. Of course, crops need nutrients to grow, and we want crops to feed the global population. But what we don’t want is to waste nutrients like nitrogen or phosphorus because we run the risk of depleting natural reserves but also because we continue to generate nitrogen in fertilizer through industrial processes that themselves are environmentally harmful. So, there’s an incentive to think about how we might harness the microbial world’s natural ability to help crops gain these nutrients. It’s been known for many decades, for instance, that certain types of microbes have symbioses with certain types of crops. Soybeans are a good example: Bacteria in the soil can naturally take nitrogen from the atmosphere and convert it into a form that the soybean plant can use. If we understood how to effect that ability more broadly across a lot of different crops, that would be a game changer. That would give us an opportunity to have a much more sustainable source of nitrogen for crops.

Orphan: The same sort of thing applies in harnessing microbial activities in the ocean. Carbon sequestration is a big question, and people are working hard to try to figure out how to utilize microorganisms. I mentioned previously these vegetated coastal ecosystems where seagrass communities are huge storages of carbon. The plant basically fixes carbon dioxide through oxygenic photosynthesis, and a lot of that carbon ends up buried in the soil. We don’t fully understand the mechanisms that are driving that. A lot of it is done by microorganisms that don’t breathe oxygen but use a whole host of different chemicals to oxidize carbon. If we can understand the secrets to the success of how that carbon gets locked in, this is another opportunity for us to enhance further carbon burial in these coastal environments.

Here are some of the other questions addressed in the video linked above:

  • Is there any evidence that microbes are mutating to thrive in higher CO2 concentrations?
  • Is there research into genetically modified microbes for end goals like promoting photosynthesis or creating alternative foods?
  • How far are we from knowing enough to be able to treat disturbed soils in specific land ecosystems to reestablish the right soil microbes and therefore optimize sequestering carbon with plant growth?
  • How close are we to utilizing the metabolic processes you’re researching to do things like metabolize greenhouse gases, clean up oil spills, etc.?



Robotic Monitoring of the Deep-Sea Carbon Cycle and Climate Change

Thought LeadersPaul McGill
Alana Sherman
Crissy Huffard

In this interview, we speak to researchers from the Monterey Bay Aquarium Research Institute about the Benthic Rover II and how it helps to monitor the deep-sea carbon cycle and climate change.

Please introduce yourself and tell us

about your background in ocean monitoring?

We are Crissy Huffard, Senior Research Specialist (marine biologist), Alana Sherman, Electrical Engineering Group Lead (electrical engineer), and Paul McGill, Electrical Engineer (electrical engineer).

The three of us work as part of a team to study deep-ocean carbon cycling at Station M, which sits 4,000 meters deep off the central California coast. Alana and Paul, along with Rich Henthorn and John Ferreira, are on the technological innovation side of the team, while Crissy works with Ken Smith to interpret data the instruments bring back.

What role does the deep seafloor play in

 carbon cycling and sequestration?

Globally, the deep ocean is a very important carbon sink. Deep-ocean carbon storage capacity ultimately influences how much carbon dioxide the ocean can take out of the atmosphere.

At Station M, seafloor communities (animals and microbes) eat a lot of this carbon (an “ingredient” of marine snow that drifts to the abyssal seafloor from the waters above) as it settles, leaving very little, if any, to be stored long term in the sediments.

Why is understanding the activities surrounding 

the deep seafloor so important?

This information ultimately helps us understand where and how much carbon gets stored in the ocean.

How was the Benthic Rover II created 

and what were the challenges faced when developing it?

The Benthic Rover II followed a first version (Benthic Rover I) that Ken Smith developed at Scripps Institution of Oceanography in the 1990s, but was lost at sea.

The Benthic Rover II was designed to accomplish the science objective to study carbon cycling and survive extreme pressure, almost-freezing temperatures, corrosive seawater, and ship operations in high seas.

What steps had to be taken to release 

the rover into the ocean originally?

To handle the corrosive, high-pressure environment, the Benthic Rover II is made almost entirely of titanium and plastic, and its flotation is provided by rugged “syntactic foam” blocks (tiny, hollow glass spheres embedded in epoxy resin) arranged to maintain an upright orientation.

The bumper protects it from just that—bumps—that might take place during deployment and recovery in the high seas.

What can the Benthic Rover II measure 

about the seafloor and how?

The Benthic Rover II’s main science objective is to help us understand carbon consumption. It lowers two acrylic chambers (with stir bars and an oxygen sensor inside) down into the sediment and measures oxygen depletion for 48 hours.

With these data, we estimate the carbon consumption by animals and microbes living there. It also takes pictures of the seafloor and records information about ambient water conditions such as currents, oxygen concentration, and temperature.

How is the Benthic Rover II recovered

every year and its findings assessed?

The Benthic Rover II is called to the surface with an acoustic signal that tells it to drop its 250-pound ballast weight. Once on the surface, we find it either by sight or using its radio and satellite beacons. The crew of MBARI’s R/V Western Flyer then recover it onto the ship.

Data are downloaded and backed up on the ship, then taken to shore for analysis of engineering performance and scientific results.

What has the data collected from Benthic Rover II over the last seven years shown?

The deep-sea is dynamic! In the past ten years, we’ve seen a large increase in the amount of carbon making its way to the deep sea. Data from the Benthic Rover II is helping us understand how much, if any, of this carbon might be stored in the sediments.

When coupled with results from other autonomous instruments at Station M, we’re even able to study what types of marine snow might be especially efficient at storing carbon in sediments.

What do your results show you about 

the future of the ocean and its role in 

climate change?

Humans’ impact on the surface ocean is translating to changes in the deep sea. Problems like ocean acidification and deoxygenation aren’t limited to the surface ocean. We need to worry about them changing the full ocean depths.

MBARI’s Benthic Rover II during a deployment at Station M, an MBARI research site off the coast of central California                Image Credit: © 2016 MBARI

What is the next stage for the Benthic Rover II?

We’re testing pH sensors to add to the system to help us better refine our estimates of carbon consumption.

Using the knowledge that the rover has given us, 

what do you think needs to be done to maintain

 the health of our oceans and planet?

Limit our total carbon emissions and educate the public on the important issue of ocean acidification.

Where can readers find more information?

About the Researchers

Crissy, Paul, and Alana work at MBARI in Moss Landing, California. MBARI (Monterey Bay Aquarium Research Institute) is a private non-profit oceanographic research center, founded by David Packard in 1987. The mission of MBARI is to advance marine science and technology to understand a changing ocean. Learn more at www.mbari.org.

 


 How Increasing Sea Temperatures Affect Marine Species Migration

Thought LeadersShahar ChaikinMarine Ecology & Biodiversity Lab
Tel-Aviv University

AZoCleantech speaks to Shahar Chaikin from Tel-Aviv University about his latest research on the role of climate change on marine species migration and distribution. This work was also conducted with Ph.D. candidate Shahar Dubiner and Professor Jonathan Belmaker. The team found that the warming climate drives marine species to migrate deeper as the ocean they live in warms. 

Can you tell us about your role at 

Tel Aviv University?

I am currently a Ph.D. candidate in Professor Jonathan (Yoni) Belmaker’s lab, School of Zoology, The Steinhardt Museum of Natural History, Tel-Aviv University.

How did you begin your research into

 marine species migration?

As far as I remember myself, I was interested in marine organisms. During my undergraduate studies, I studied seasonal migrations of rays as part of their assumed breeding season. Since then, I began a direct Ph.D. program that allowed me to further expand my study for other marine organisms and explore the potential effects of climate change on species distributions. Together with my supervisor Yoni, we established my Ph.D. dissertation, aimed at elucidating patterns and drivers underlying marine species depth distributions.

What were the key findings of your 

recent study on marine animal migration?

We found evidence that an increasingly warming climate may drive marine species such as fish, cephalopods, and crustaceans to compress their depth distributions. This means that their minimum depth limits (i.e., shallow depth limits) are deepening with warming. Furthermore, the amount of deepening is strongly related to species traits. For instance, cold-water species may deepen more than warm-water species.

This image of fish and cephalopods was taken on the Israeli coast in the Mediterranean Sea. Image Credit: Shahar Chaikin

Why is understanding marine species behavior important?

The oceans encompass most of our planet and have an important role in supplying vital services for both humans and the surrounding organisms such as oxygen and food. Understanding species responses to a changing climate may allow us to predict the potential distribution of important food resources, the efficiency of our future marine protected areas, and the species composition of our future oceans.

What implications does this study have

for fishing and future marine nature reserves?

Our ocean’s biota is undergoing a constant change with the shift of our climate. We assume that letting our current MPAs conserve the same habitats and grounds through time may not serve the same amount of protection for the future marine communities, as their distributions are also about to change.

Similarly, and based on our models, fishery grounds are predicted to deepen for cold-water and deep-water species in particular. Conversely, shallow-water species may not be able to deepen to cope with increasingly warming waters. Therefore, they may have to adapt as deeper environments may not serve as an optimal habitat.

How has the planet’s warming had a direct

 impact on the Mediterranean Sea in particular?

The semi-enclosed nature of the Mediterranean Sea makes it particularly sensitive to climate change. As a result, it is notorious for having one of the greatest warming rates in the world. For instance, the upper waters of the  Levantine basin have a warming rate of about 1.2 ℃ per decade which is about twice the warming rate in the entire Mediterranean Sea, a hotspot for climate change.

Generally, cold Atlantic waters are entering the Strait of Gibraltar. These waters flow across the North African shelf and are becoming constantly warmer, saltier (due to evaporation), and poor in nutrients (due to consumption by organisms) while reaching the Levant, the eastern warm edge of the Mediterranean. These waters continue to flow north and then west until they exit the Mediterranean Sea back to the Atlantic Ocean. This process may take approximately 100 years in terms of residence time.

How has sea temperature changed in the last

100 years?

Globally, according to Intergovernmental Panel on Climate Change, it appears that since the 1970s, our oceans are constantly warming and at rates that have near doubled since the early 1990s. As mentioned above, some environments are getting warmer than the global average, and we should remember that each ecosystem has its unique conditions.

How is the migratory pattern different in

 warm-water species and cold-water species?

We found that cold-water species are more sensitive to warming. This was evident with greater minimum depth deepenings for cold-water species (i.e species with affinity to cold waters such as the Atlantic mackerel) while compared to warm-water species (e.g., Whiskered sole). This pattern was true for the whole species pool, including fish, crustaceans, and cephalopods.

Before this study, we mainly knew anecdotal examples for species that inhabit shallow water in the Western Mediterranean Sea and dwell in deep waters in the Eastern Mediterranean. Therefore, creating a broad generalization across 236 marine Mediterranean species was an alarming and important understanding.

Were there any key challenges in your research

and how were these overcome?

While conducting a meta-analysis, there are usually many challenges associated with data quality control and standardization across the studies. We had to execute several sensitivity analyses to make sure that our results are not biased by sample locations, sampling intensity, and other potential biases associated with bottom-trawling. After combining all these analyses and closely observing the patterns, we were able to confidently report our results and conclusions.

How should decision-makers prepare in advance 

for the deepening of species?

I believe that decision-makers must have detailed plans for the future. For instance, marine protected area planners should also consider including deep habitats and not protecting only shallow and coastal ecosystems. Specifically, I recommend that each MPA should have a species list combined with species traits to understand the proportion of species of various thermal preferences, depth preferences, and levels of generalism-specialism. These may allow better decision-making according to species’ predicted depth changes.

Unfortunately, I believe that some species such as shallow-water species might be at greater risk than others (e.g. herbivores might not find suitable food at depths). This means that protecting them from overfishing might not always be enough.

Do you have any further research you would 

like to discuss?

In this study, we mainly underscore species’ predicted depth distributions with warming. We did not have data on whether these species are thriving or challenged by redistributions. It is difficult to understand whether deepening species are increasing or decreasing their fitness. Our current study’s overarching goal is to fill this knowledge gap. 

About Shahar Chaikin

I am currently a Ph.D. candidate in Professor Jonathan (Yoni) Belmaker’s lab, School of Zoology, The Steinhardt Museum of Natural History, Tel-Aviv University.

My current dissertation looks at how marine species are impacted by climate change and specifically explaining whether some are facing greater risks with warming. To deal with these questions I use both macroecological and local approaches using data science and field samplings.

I am also a co-founder of “Sharks in Israel”, an NGO that helps protect sharks and rays along the Israeli coast.