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Science at the Academy

scientist teaching students with specimens

Invertebrate Paleontologist Studies How Ecosystems are Responding to our Changing Environment

Jocelyn Sessa, PhD, assistant curator of invertebrate paleontology, is one of many scientists at the Academy researching how ecosystems are responding to our changing environment. She studies the “canary in the coal mine” for acidification of the ocean – pteropods. Pteropods are tiny snails with thin, translucent shells. Although they’re the size of a grain of sugar, they’re an incredibly important indicator of what is happening in an ecosystem because their shells are especially prone to dissolution by ocean acidification. Ocean acidification has been occurring since the industrial revolution. As ever more CO2 is pumped into our atmosphere, the ocean absorbs it and becomes more acidic, making it harder for organisms like pteropods to grow their shells. Pteropods are a crucial part of the marine food web — a staple for whales, cod, shrimp, krill and more — and changes that impact them impact the entire ocean ecosystem. Sessa analyzes both modern and historical specimens from museum collections. Her goal is to determine a baseline of pteropod shell thickness over time and understand how ocean acidification may have affected shell growth. Find out more on the Academy blog.

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scientists look for mussels in river

Mussel Survey

In late September, Academy staff scientists and collaborators conducted a mussel survey on the Schuylkill River upstream from Boathouse Row. Their goal was to document the presence or absence of mussels and, in particular, whether there were any Tidewater Mucket (Leptodea ochracea) in this stretch of the river. This survey was the last in a series that was conducted throughout the lower Delaware River watershed.

Click here for details and to see more photos.


New Shipworm Eats Stone

The Academy’s Gary Rosenberg, PhD, was part of a team that examined and described a new anatomically and morphologically divergent species of shipworm which was published recently by The Royal Society. This shipworm’s taste for rock sets the bivalve apart from thousands of others. Although other animals burrow in stone, this new species, Lithoredo abatanica, is unique in that it actually eats the rock as it burrows, expelling sand as feces.

Read more:

compost stew

Reading List: Taking Care of the Environment

You probably care deeply about keeping the environment clean. You likely take steps to be an environmental steward, perhaps rinsing and sorting your recycling, composting, conserving water, reusing items and more. You may even encourage members of your household to do the same. But have you considered how to explain the importance of these actions to your kids, grandkids, nieces, nephews or friends? How will you help to prepare the next generation to work hard to make the planet a more sustainable place?

Whether you’re seeking a starting point for conversation, you want to further your own knowledge or you’re looking to join a global movement, our reading list will help you find a place to start.

Our List:


A Real Shocking Discovery

Academy Ichthyologist Mark Sabaj is one of the co-authors on the descriptions of two new species of electric eel.  

Scientists have discovered a new species of eel that can discharge up to 860 volts of electricity – significantly more than the 650 volts previously recorded by what had been believed to be the only type of eel in existence… until now.

Mark Sabaj, PhD, interim curator of fishes at the Academy of Natural Sciences of Drexel University is well-versed in techniques for catching electric eels both with and without getting shocked. He contributed to a large study of electric eels as a member of a multinational team led by Carlos David de Santana, an ichthyologist at the National Museum of Natural History in Washington, D.C. Sabaj is a co-author on the descriptions of two new species, Electrophorus voltai and Electrophorus varii, published in Nature Communications.

Click here to read the full Q & A with Mark Sabaj on the Academy Blog.

scientists on boat

Four Ways to Cut Your Carbon

Looking to reduce your personal carbon emissions? There are some big steps you can take. For example, if you need to travel a long distance, you can choose rail or even sailboat — to follow in Greta Thunberg’s wake — rather than flying. The 16-year-old Swedish climate activist last week completed a transatlantic journey by racing yacht to attend the United Nations summit meeting on global warming this month. Few of us fly every day, and fewer sail. So how can we do our part to reduce CO2 emissions (which contribute to harmful greenhouse gases largely blamed for driving global warming) in our daily life?

Click here for four ways you can reduce your carbon.

tree on fire 

How Does a Rainforest Catch Fire?

Characterized by high levels of rainfall – it seems peculiar that a massive fire could take root in a rainforest region. That is why understanding exactly how and why Brazil’s Amazonian rainforest was set ablaze is particularly important. 

Academy scientists explain what is happening with the fires in Brazil. Click here for the full post:

wildflower illustrations

A Relic of Botany History

Dr. Carl Ludwig Willdenow’s Anleitung zum Selbststudium der Botanik: ein Handbuch zu öffentlichen Vorlesungen (Dr. Carl Ludwig Willdenow’s Guide to Self-Study of Botany: A Handbook for Public Lectures) has been added to the Academy's library. Willdenow is a major figure in the field of botany. The book was not previously contained in our vast collection and contains several brilliantly colored plates. 

Learn more about the title's addition to the Academy:

academy scientists in creek

Time Outdoors: It’s Healthy

Doctors and psychologists have long recognized that spending time in nature leads to a healthier well-being, and a growing field of research aims to better understand and quantify the benefits of spending time in nature. Time spent outdoors is related to lower stress levels, decreased blood pressure, and a reduced risk of chronic diseases such as asthma, allergies, diabetes and cardiovascular disease.

So, if the prescription is to spend more time in nature, what’s the dosage? A recent The New York Times article highlights some new findings, namely that researchers have zeroed in on the ideal amount of outdoor time for reaping nature’s maximum health benefits: 120 minutes per week. Two hours in a week doesn’t seem like a lot of time, but it can sometimes be difficult to fit that time into our already hectic schedules.

Click here for some easy suggestions for adding 120 minutes of outdoor time to your week. 

Fork-tailed Flycatcher Photo by Jason Weckstein/ANS

Amazonian Birds

Last spring, ornithologists Jason Weckstein and Nate Rice brought back the first cache of birds from Brazil to be added to the Academy’s Ornithology Collection since the 1920s. The scientists and their colleagues collected and preserved the birds, along with thousands of tissue and parasite samples, during three collaborative expeditions to the region. The researchers hope to gain a better understanding of the basic principles of how pathogens and parasites are transmitted and evolve.

Read more:

scientists on boat

Where Does Your Water Come From?

The Wissahickon Creek watershed is 64 square miles and covers portions of Montgomery and Philadelphia counties in Pennsylvania. The Wissahickon is a small but important part of a larger system. It is a tributary of the Schuylkill River, which in turn is the largest tributary of the Delaware River. The whole Delaware River Basin covers 13,500 square miles and provides water for more than 15 million people, including half of New York City’s potable water supply. Do you know the source of your drinking water?

Read more:

scientists in stream

Keeping Tabs on the Environment

Summertime means the height of field work season for many Academy scientists. They can be found up and down the Delaware River watershed measuring fish, collecting algae samples, measuring sea level rise due to climate change, testing water for the presence of harmful chemicals and more. Wading in cool streams, hiking bucolic trails, walking through wetlands, and boating to find the fish are all involved. But so are smacking mosquitoes, sweating in waders, battling sun burn, and lugging equipment in heat and humidity. But all in all our scientists agree: it beats sitting in the office! 

Learn where our scientists are this summer.

pristine mountain stream

Five Things You Can Do Now to Help the Environment

Did you know that a recycling shipment with as little as 0.5% non-recyclables can be considered unusable and trashed? Are you aware that livestock is a major source of greenhouse gasses and that eating less could reduce your environmental impact? Have you tried adjusting your thermostat one degree to save 10% on your energy use? Learn five things you can do to reduce your footprint on our earth.

Read more:

exterior of the Academy of Natural Sciences

Academy Blog

Covering topics ranging from environmental science to collections and field research, the Academy blog is a one-stop-shop for our latest science news. Expect to hear from our usual Academy writers and communicators, plus lots of others who work at the museum, in the lab or in the field every day. You may see pictures or videos from the field, hear a scientist’s commentary on a research trip or discovery or learn more about an item in the Academy’s collections. You’ll also get information about upcoming events and exhibits, opportunities for families and membership at the Academy.


freshwater mussels in drawers

Academy Science News

Through our monthly science newsletter, we keep you up to date on what our scientists are publishing, what science events are happening and where the Academy has appeared in recent science news both locally and nationally. Sign up below and make sure to elect to receive science news emails when you choose your email preferences.

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scientist with entomology specimens

Support Science

Make a difference today with your gift to the Academy’s Annual Fund. The Annual Fund provides vital support for the Academy’s most critical needs, including research, collections care, education and exhibits. Your support of the Annual Fund will protect the Academy’s irreplaceable collections, including the Lewis and Clark Expedition’s botany collection and John James Audubon’s birds; support world-class research addressing today’s most significant questions in environmental science, biodiversity and evolution; help support science education for more than 80,000 schoolchildren each year; and fund outstanding exhibitions, educational programs and environmental forums for learners of all ages.

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