Marine Environment

Fish are good at disregarding fake news

Anonymous — Thu, 30 Mar 2023 18:42:51 +0000

Fish are good at disregarding fake news Anonymous (not verified) Thu, 03/30/2023 - 12:42

Bradley Worrell

Published research co-authored by CU �鶹ӰԺ marine biologist shows that coral reef fish can make dynamic adjustments in their sensitivity to information from other fish to suppress the spread of misinformation

If you want to understand how wild animals deal with socially transmitted misinformation, examining the habits coral reef fish is a pretty good place to start.

In a nutshell, that’s the assessment of a research paper recently published in The Proceedings of the National Academy of Sciences, a peer-reviewed journal of the National Academy of Sciences (NAS), an authoritative source of original research that broadly spans the biological, physical and social sciences.

The paper, titled “Wild Animals Suppress the Spread of Socially-Transmitted Misinformation”, was co-authored by Mike Gil, �鶹ӰԺ marine biologist and assistant professor of ecology and evolutionary biology.

At top of page: A fish feeds on algae on a coral reef, fulfilling a vital function for maintaining a healthy underwater ecosystem. Coral reef fish are social beings that are adept communicating information about food, shelter and possible predators to nearby fish. Above: In their recent paper, researchers place several video cameras on a coral reef to continuously observe fish behavior and then using artificial intelligence to help analyze the videos. Still, CU marine biologist Mike Gil has spent considerable time in the water observing fish behavior for himself.

“It turns out that Disney’s ‘Finding Nemo’ might have been closer to reality than you probably thought,” Gil says. “Fish in coral reefs are, indeed, social beings.”

He explains that information from neighboring fish can be very useful, because it can help an individual fish find resources like food or shelter—or it can provide them with an early warning for shared dangers, such as an approaching shark.

“But these reef fish—like humans—can also behave in ways that can mislead others,” he says. “For example, when they are out and about, feeding from the reef, fish commonly mistake benign environmental cues for danger, and will spontaneously flee—as if they’re being hunted by a predator.

“Such dramatic escape behavior is energetically costly to the individual,” Gil says, noting that in those instances the fish—described by researchers as a “first responder”—executes an escape maneuver involving a deep body bend followed by large acceleration and rapid turning.

That motion, in turn, sends sensory information to surrounding individuals, “telling them that danger could be near, and they, too, may want to stop feeding and swim for their lives,” he adds.

Given that any fish is capable of such spontaneous flight behavior, Gil says researchers’ initial hypothesis was that the larger the group of fish, the greater the chance that any one fish would trigger a false alarm that could startle the whole group.

“And so our expectation would be that larger groups of fish will be increasingly likely to fall victim to energetically costly misinformation cascades that disrupt their feeding behavior. But, to our surprise, we do not see this,” he says.

A coral reef fish swims in front of Gil, in a wetsuit. In a recent research paper co-authored by Gil, researchers determined that coral reef fish can adjust their sensitivity to information from other fish to suppress the spread of misinformation that could otherwise cause them to overreact and effectively become dysfunctional.

While some escape events involve large response cascades, most involve only one or a few responders, according to Gil.

“What we found was that when these fish were surrounded by more neighboring fish, they dialed down their responsiveness to information from any given neighbor,” he says. “Each individual fish’s willingness to essentially ignore information from one or a few individuals behaving in an extreme way largely prevented the entire group from being misled by misinformation. Instead, these groups of fish are able to carry on eating, largely undisturbed by frequent exposure to misinformation.”

Gil says the researchers reached their conclusions by placing several video cameras on a coral reef to continuously observe fish behavior and then using artificial intelligence to help analyze the videos.

In their paper, the researchers showed that in natural foraging collectives escape events in the absence of true predatory threats occur frequently, at a mean rate of one event per 7.7 minutes. Gil says that, if coral reef fish acted on all of the false warnings they are given, the effect would be devastating to both the fish and coral reefs.

“Perhaps what is most remarkable about our findings is that if reef fish behaved in more conventional ways—including in ways that resemble human behavior—large groups of fish would be distracted so frequently by misinformation cascades that they could become dysfunctional—meaning their ecological role would not be fulfilled,” he says.

“For the fish species we’re studying, that would mean algae that these fish ‘clean’ (meaning eat) from the sea floor could accumulate and kill corals that form the basis for the ecosystem. Fortunately for the many creatures that depend on coral reefs, including humans, it appears that nature has a built-in defense against such misinformation-induced dysfunction.”

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Marine biologist probes importance of diversity

Anonymous — Fri, 20 Jan 2023 17:28:53 +0000

Marine biologist probes importance of diversity Anonymous (not verified) Fri, 01/20/2023 - 10:28

Bradley Worrell

Let’s CU Well presentation on Jan. 30 by CU �鶹ӰԺ professor to highlight diversity’s importance in many settings

Diversity is important to the health of any ecosystem—whether it’s a coral reef or a university campus.

That’s the message Mike Gil, marine biologist and �鶹ӰԺ assistant professor of ecology and evolutionary biology, will deliver in an upcoming seminar titled “Coral Reefs, and Science, and YouTube, Oh my! How diversity can save the world.”

This event is scheduled as a Zoom presentation starting at 1 p.m. on Monday, Jan. 30. The event is free, but registration is required, at this link.

The presentation is part of the Let’s CU Well speaker series, which is part of Be Well, the College of Arts and Sciences’ wellness initiative.

Mike Gil giving a talk at the University of Aruba.

Gil, who recently won a $3 million grant from the National Science Foundation (NSF), leads a research program that uses field experiments and mathematical modeling to decipher how natural ecosystems work and, thus, how we can better manage these ecosystems for their sustainable use.

Gil’s primary area of study is one of the most threatened ecosystems in the world: tropical coral reefs. Gil and his collaborators turn large areas of coral reefs into “natural observatories,” in which the behavior of every visible fish and invertebrate can be video recorded and—with the help of artificial intelligence—carefully tracked.

With such unprecedented data, Gil is discovering the hidden rules that govern animal decision-making and then using these rules to build more realistic mathematical simulations of ecosystems that can assist with natural resource management and conservation.

For example, Gil and his colleagues discovered that the behavior of a community of reef fish species is heavily influenced by their social networks and that when we account for these social connections the ecosystem behaves dramatically differently in the long term than we thought.

Gil scuba diving over coral reef.

With the NSF funding, Gil and his team will examine the role that diversity in fish social networks plays in the greater ecosystem.

“We already see striking differences in the behavior of different fish species within the same social network. For example, some species appear to be more vigilant—more responsive to threats, while others seem to lead surrounding fish to safe feeding grounds.”

But discovering the “behavioral roles” of different fish species doesn’t just help us understand how and why aggregations of fish behave the way they do; it can help us understand the whole ecosystem.

“This diversity in behavioral roles could give rise to substantial effects at the ecosystem scale, especially when we consider such practices as overfishing that can drive local extinctions of certain fish species,” he says.

Gil hopes that his team’s research can play a role in preserving coral reefs for the estimated 1 billion people whose livelihoods depend on these ecosystems.

“We cannot forget that coral reefs are not just gorgeous, inspiring places to visit or to watch on TV, but they are responsible for the health and well-being of entire regions of people, especially in developing tropical nations—some of the most vulnerable people on the planet,” Gil says, adding:

“The role that diversity plays in the functioning and persistence of coral reefs remains an open question, but one that we now have the technology to address in new and exciting ways.”

In talking about diversity, Gil highlights his own unlikely road to becoming a marine biologist. The son of a Latin American immigrant and raised by a single mother, Gil attended underfunded public schools outside of Houston, Texas, where he says schoolwork was drudgery because it was taught with a focus on passing standardized tests.

“So, I had no interest in science. I thought science was just a bunch of unrelatable facts,” he says. “What I was taught was the history of science—not the actual process of scientific discovery—and so I didn't even know what science actually was. How could I possibly know that I want to be a part of something that I never even got introduced to?”

Ultimately, Gil says that while he had no personal connection to science, he did love observing nature, albeit largely indoors. As a child, he spent countless hours watching National Geographic and Discovery Channel documentaries.

“I didn't even really know about the world of outdoor recreation, and certainly nothing about careers in biology, where you get to work out in nature. So, my experience was TV—through watching television and seeing nature, documentary-style,” he says. It was in college that his path to becoming a marine biologist became clear, he adds.

Under the water's surface, Gil takes photo with a shark in the top right corner.

“Starting as someone with no connection to science to becoming a scientist, leading cutting-edge research on coral reefs … it has been a very unlikely path,” Gil says. “But now I feel like I’ve hit the lottery. I get to live a really fun, exciting life, having adventures and visiting coral reefs around the world.”

With his background, Gil says it’s important to him to be a mentor to the vast numbers of people, who, like him, didn’t have access to an education that revealed what science really is or what opportunities STEM careers offer.

One way he’s done that is by creating SciAll.org, a mass communication platform using vlogging (video blogging) to humanize scientists and demystify the process of scientific discovery to make personal connections to STEM possible for all.

“There is a moral obligation to include more people in this exciting, adventurous life that we get to live as research scientists,” Gil says.

Let’s CU Well presentation on Jan. 30 by CU �鶹ӰԺ professor to highlight diversity’s importance in many settings.

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A Lesson from the Past?

Anonymous — Tue, 20 Dec 2022 16:03:35 +0000

A Lesson from the Past? Anonymous (not verified) Tue, 12/20/2022 - 09:03

Robert L Hohlfelder

Marine concrete from the Roman empire has proven to stand the test of time—and offers insights into ways to combat rising sea levels now

Throughout the Mediterranean Sea, scores of ancient marine concrete monuments, once components of artificial harbors constructed by Roman builders as part of their vast imperial maritime infrastructure, have survived for two millennia and counting.

Modern marine concrete usually survives in the sea for little more than 50 years and sometimes even less. What did Roman builders know that modern harbor engineers did not? This was one of the questions that the Roman Maritime Concrete Study, an international, multidisciplinary project that I organized and co-directed in the first decade of this century, hoped to answer.

Field work was undertaken to collect and analyze concrete cores extracted from submerged structures at various ancient harbor sites in Greece, Italy, Cyprus, Israel and Egypt. The results of this study were published in Building for Eternity: The History and Technology of Roman Concrete Engineering in the Sea in 2014 with a reprint in 2021.

At the top of the page: The last stages of the reproduction of a small marine concrete block using the same materials from the Bay of Naples in the harbor of Brindisi, Italy. Above: A massive concrete block, c. 15x11x4 m, discovered in the harbor of Caesarea Maritima, Israel.

The key ingredient responsible for the amazing durability of Roman marine concrete was volcanic ash or sand from the Bay of Naples, called pulvis puteolanus. It was the binding element in the mortar that, along with aggregate, comprised the concrete itself.

This Neapolitan volcanic ash has a unique chemical composition. When it was mixed with quick lime and seawater, to which rock aggregate was added, the resulting concrete could be placed while still in a liquid state into the sea within a variety of wooden formworks to set quickly and then cure over time. The internal chemical processes that occurred as the concrete cured underwater eventually reduced the porosity of the surface of the concrete block until it became like rock itself. Some scientists have claimed that Roman marine concrete is the most durable substance yet created by humankind.

Obviously, there is not enough volcanic ash in the Bay of Naples region to meet the demands of today’s world. However, material scientists throughout the world are using the data published in Building for Eternity as a starting point in efforts to recreate the chemical processes that occurred in Roman marine concrete that made it so durable—which could become even more important as sea levels rise in response to a warming climate.

NOAA scientists have predicted a sea level rise of at least 2 meters by the end of this century, and this might be a conservative estimate. If this prediction is close to being accurate, all of our coastal cities are at risk of flooding. There will be mass migration of our coastal populations to places like Colorado. But, if a new form of concrete could be used to build durable, long-lived seawalls at critical locations, say along the shores of Manhattan, perhaps our coastal cities might be able to survive.

Such seawalls, of course, would be only one part of future efforts to mitigate the sea level increase that threatens our future.

In addition, perhaps new marine concrete containers that, over time would become indistinguishable from rock itself, might provide one answer to how society safely stores nuclear waste and spent nuclear fuel. On-site steel and concrete barrels, now used as storage containers in scores of locations scattered around our country, are not the answer, since they eventually will leak. New containers made of this impervious marine concrete might well prove to be better receptacles.

After hazardous nuclear material was emplaced, they could then be shipped safely to the Yucca Mountain Nuclear Waste Repository (YMNWR) to be stored in the caverns in this mountain. If so, we would have gone a long way to solving the issue of nuclear waste storage or disposal for perhaps the million years that was the hoped-for goal for the YMNWR. Moreover, there would be little possibility of leakage into nearby aquifers during these millennia.

As I often said to students in my classes, the ancients keep stealing our good ideas. When it comes to improving our marine concrete, we may learn a lesson from the distant past.

Marine concrete from the Roman empire has proven to stand the test of time—and offers insights into ways to combat rising sea levels now.

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