Category Archives: Ecology

Why Are Nebraska’s Birds Turning White?

The following post is one of a series previewing the research that will be presented at the SETAC North America 42nd Annual Meeting (SciCon4), 14–18 November.

A guest post by Lauren Gillespie, Central Community College-Columbus

A block of four different photos of birds, two showing white feathers, one showing asymmetrical tail feathers, and the fourth showing a swallow with normal coloration.
Photo 1: A. The first barn swallow with partial leucism we caught in 2018; B. An example of the white feathers we have found in many individuals; C.  An example of tail streamer deformation and asymmetry; D. A barn swallow with typical melanin coloration.

I teach general biology at Central Community CollegeColumbus (CCC-C) in Nebraska, where I hold ecology lab courses at a nearby creek with students in waders performing water quality tests. This “creek” is a glorified agricultural drainage ditch, bordered by farmland in a state that crop-dusts on a regular basis throughout the summer months. I saw birds nesting underneath the bridge once and decided on a whim to mist net during a lab session. Mist nets are used to capture birds and can only be purchased with proof of a U.S. Fish and Wildlife collecting permit. As students took samples, I extracted the bird—a barn swallow (photo 1, A)—that started this project.

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Integrating Knowledge on the Distribution and Maternal Transfer of Organic Pollutants to Advance Sea Turtle Conservation

The following post is one of a series previewing the research that will be presented at the SETAC North America 42nd Annual Meeting (SciCon4), 14–18 November 2021.

A guest post by Cynthia C. Muñoz and Peter Vermeiren, Radboud University, The Netherlands

Knowledge regarding the internal distribution and subsequent maternal transfer of organic pollutants—such as polychlorinated biphenyls (PCBs), once used in electical equipment and plastics; organochlorine pesticides (OCPs), and polybrominated diphenyl ethers (PBDEs), which make materials nonflammable—within organisms is of critical importance to scientists who interpret tissue-specific biomonitoring results and refine risk assessments. Although the manufacture and/or use of most of these chemicals were banned decades ago, they persist in the environment and accumulate in wildlife. This is particularly true for long-lived organisms, such as sea turtles, where pollution burdens build up over time and affect health later in life. Moreover, organic pollutants can accumulate over many years before being transferred from the mother to its offspring, where they can interfere with critical development processes. For example, maternal transfer of organic pollutants into yolk, through the placental barrier, or during lactation has been linked to decreased survival rates and impaired embryo and juvenile development in several long-lived vertebrate species. Yet knowledge on the internal and maternal distribution of organic pollutants remains limited for many such species, due to ethical, economic, and logistical restrictions on sampling them, as many are threatened or endangered. Additionally, a diverse chemical universe of legacy, new, and emerging organic pollutants is present in the environment, of which the behavior within the environment and upon contact with long-lived species is largely unknown. In short, the challenge of refining risk assessments specific to the characteristics of long-lived species, such as sea turtles, is complex, without an easy solution.

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Evolution by Pesticides: Evidence of Evolution in American Alligators Affected by Endocrine Disrupting Chemicals

The following post is one of a series previewing the research that will be presented at the SETAC North America 42nd Annual Meeting (SciCon4), 14–18 November 2021.

A guest post by Yeraldi Loera, Ph.D. student at Princeton University

Baby alligator rests in open palm.
Solo gator. Photo courtesy of the author.

Instances of environmental pollution by manufactured contaminants are widespread across the globe. Pesticides are commonly used in agriculture to combat pests, but can also harm other, non-targeted organisms. Exposure to some pesticides can lead to disruption in the endocrine system, altering reproductive development and fitness. One study showed this kind of disruptive effect across populations of American alligators (Alligator mississipiensis) that were exposed to a pesticide (DDT) spill in Lake Apopka, Florida. Surprisingly, another study in the same region showed a rebound in the population following their exposure, suggesting possible evolved resistance to pesticide contamination.

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An Unexpected Source of Mercury: Greenland’s Glaciers

By Roberta Attanasio, IEAM Blog Editor

Greenland. Credit: Rene Schwietzke (CC BY 2.0).

Greenland, the largest island in the world not considered its own continent, lies above the Arctic Circle with the exception of its Southern tip. Ice—the Greenland Ice Sheet—is everywhere but is rapidly becoming a major contributor to sea level rise as it melts because of climate change. Now, a new study shows that the resulting freshwater (or meltwater) runs off to the ocean taking along an unexpected and toxic companion—mercury, a chemical that when transformed into methylmercury bioaccumulates and biomagnifies in fish, shellfish, and animals that eat fish, causing nervous system damage and other deleterious effects in humans and wildlife.

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Understanding Underwater Sounds: Evaluating Risks of Human Activities

Commercial shipping density (red lines).
Credit: B.S. Halpern (T. Hengl; D. Groll) / Wikimedia Commons / CC BY-SA 3.0

A guest post by Andrew McQueen, US Army Corps of Engineers

Researchers around the world are focusing more on the role of anthropogenic (human-made) sounds in marine ecosystems. In the last half century, as we have industrialized and expanded our use of the “blue” ocean economy (maritime transport, fisheries, and renewable energy), some regions have observed incremental increases of anthropogenic underwater sounds. However, the ecological consequences, or risks, of these changing underwater soundscapes remain largely unknown.

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Lost Wilderness: Restoring both Habitat and Animal Species

Photo credit: Hannes Flo, CC BY 2.0.

By Roberta Attanasio, IEAM Blog Editor

A month after the death of Henry David Thoreau, The Atlantic published his 1862 essay “Walking,” which “extolled the virtues of immersing oneself in nature and lamented the inevitable encroachment of private ownership upon the wilderness.” It included Thoreau’s famous line “In wildness is the preservation of the world”—eight powerful words that played a major role in saving places such as Yosemite and Cape Cod from human-caused environmental destruction, inspiring the creation of the US National Parks system. Upon signing the US Wilderness Act in 1964, President Lyndon B. Johnson stated: “If future generations are to remember us with gratitude rather than contempt, we must leave them more than the miracles of technology. We must leave them a glimpse of the world as it was in the beginning, not just after we got through with it.” Continue reading

Biodiversity Under Attack in Rivers: Human Activities Cause Changes All Around the Globe

Roberta Attanasio, IEAM Blog Editor

On 18 February, the United Nations Environment Programme (UNEP) released a report highlighting the three major emergencies that are currently challenging the entire planet— climate, biodiversity, and pollution. “Making peace with nature: A scientific blueprint to tackle the climate, biodiversity and pollution emergencies” is based on evidence from global environmental assessments. “Humanity is waging war on nature. This is senseless and suicidal. The consequences of our recklessness are already apparent in human suffering, towering economic losses, and the accelerating erosion of life on Earth,” said António Guterres, Secretary-General of the United Nations in the report foreword.

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Ancient Marine Mammal Bones Record Dynamic Change in Mercury Concentrations Over the Last 3000 Years

The following post is one of a series previewing the research that will be presented at the SETAC North America 41st Annual Meeting (SciCon2), 15–19 November 2020.

A guest post by Julie P. Avery, Nicole Misarti, Todd M. O’Hara, and Lorrie D. Rea

Do you like fish?  Have you heard warnings from the FDA about consuming predatory fish such as tuna, swordfish, and shark due to high mercury? Fish are a healthy food and an excellent source of lean protein, healthy omega-3 fats, vitamin D, iron, selenium, zinc, and iodine. Fish provide all these nutrients, which are essential for human and animal health. Marine mammals in Alaska, like Steller sea lions and northern fur seals, thrive on a diverse fish diet. But what about the mercury? Since we eat some of the same fish as seals and sea lions, we can study them to understand how mercury might affect humans. 

Coastal and Arctic communities are especially vulnerable to the effects of mercury contamination due to their dependence on fish and marine resources for food and sociocultural needs. According to the World Health Organization, mercury is one of the top 10 contaminants of concern for human health.  

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“Humanity at a Crossroads”: How Will Future Generations Experience the Natural World?

By Roberta Attanasio, IEAM Blog Editor

Hopetoun Falls
Photo by DAVID ILIFF, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=43330268

In 2009, the United Nations (UN) General Assembly acknowledged that the Earth and its ecosystems are our common home and adopted its first resolution on “Harmony with Nature.” It recognized that while Nature has been treated as a commodity that exists largely for the benefit of people, it is now necessary to achieve a just balance among the economic, social, and environmental needs of present and future generations. Since then, the UN General Assembly has adopted eleven resolutions on Harmony with Nature.

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COVID-19 and the “Anthropause”: Studying the Impact on Human-Wildlife Interactions

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Urban coyote (Canis latrans). Credit: Connar L’Ecuyer for US National Park Service (public domain).

By Roberta Attanasio, IEAM Blog Editor

Since COVID-19 started spreading worldwide during the first months of this year, we’ve heard intriguing stories and watched fascinating videos of wildlife emerging in city streets emptied by lockdown measures, even in metropolitan areas. The “great pause” has brought about unexpected effects. “Peacocks stroll the streets of Ronda, Spain; a gang of goats wander around a seaside town in north Wales; a puma climbs down from the Andes Mountains into Santiago, Chile; and coyotes trot around San Francisco.” Continue reading