Interview: Sheean Haley, biological oceanographer and the chair of the Lamont Ecosystem Impacts & Stewardship Committee.

Sheean Haley is a biological oceanographer and Senior Staff Associate III at the Lamont-Doherty Earth Observatory of Columbia University. She also serves as the chair of the Lamont Ecosystem Impacts & Stewardship Committee (LEISC).

She works within the Dyhrman Microbial Oceanography Group, alongside Principal Investigator Sonya Dyhrman. The lab group’s work focuses on using molecular tools, including genomics, transcriptomics, and proteomics, to investigate how marine phytoplankton respond to environmental change.

By using the information coded within the genetic material – DNA, RNA, and proteins – of marine phytoplankton, the Dyhrman Microbial Oceanography Group can begin to map out how changes in environmental parameters like temperature, carbon dioxide concentration, and nutrient supply influence the composition and behavior of phytoplankton communities, including those that can produce harmful algal blooms.

Sheean frequently develops educational activities and leads community outreach programs, such as The Artistic Oceanographer and the "Better Know a Marine Microbe" series, aimed broadly at increasing ocean science literacy.

1. Tell us about your journey to becoming a biological oceanographer

I started college wanting to become a veterinarian for large animals.  I majored in Biology, taking all the relevant courses that would set me up for veterinary school.  But, along the way one course changed my career trajectory.  I took an Ecotoxicology course, and a portion of that class focused on natural toxins –think animal venoms and plant toxins – and I learned that some marine phytoplankton produce neurotoxins 1000 times more potent than the nerve gas sarin.  That really made an impression on me!  How could something smaller than the diameter of a single human hair have such an outsized weapon?  This is what put me on a different path away from veterinary medicine – and organisms you can see with your naked eye – toward microbial ones that you can’t see without a microscope!

I did a senior research project on some of these neurotoxin-producing phytoplankton, called dinoflagellates, and these microscopic organisms launched me into a Master’s degree in Biological Oceanography at the University of Connecticut and eventually to my position as a scientist at Lamont-Doherty Earth Observatory in New York.

2. Did you have any role models that influenced your career focus?

My parents gave me a strong appreciation for the natural world and discovery.  I grew up in a very rural part of Pennsylvania, and I spent a lot of my time outside surrounded by woods and streams.  I think that was a good foundation to begin to appreciate the things that are really important to our well-being, but are hard to see and therefore underappreciated.

3. What are marine phytoplankton?  What function do they serve?

Marine phytoplankton are superheroes!  Found in the sun-lit surface waters of the ocean, these microscopic photosynthetic plant-like organisms make our planet habitable and form the base of the marine food web.  Marine phytoplankton, sometimes simply referred to as algae, are photosynthetic; they use energy from the sun, along with carbon dioxide and water, to make sugars (food!).  This process removes carbon dioxide from our atmosphere and generates oxygen.

These single-celled organisms are so abundant in our oceans that they generate about 50% of the global oxygen!  And, as the base – or bottom – of the marine food web, marine phytoplankton are responsible for sustaining nearly all other organisms in the ocean, and many on land, including humans.  Marine phytoplankton perform these incredible, life-sustaining services and yet they do it unseen.

4.  How does climate change and pollution impact phytoplankton?

Phytoplankton, like land-plants, need sunlight, carbon dioxide, water, and nutrients to grow.  And, just like different kinds of land-plants, different kinds of phytoplankton have their own optimal temperature ranges at which they can grow. Human-caused climate change has increased ocean temperature; in fact, the average surface ocean temperature this year is the highest ever recorded.  Intense warming of surface waters can create layering, or stratification, in the water that prevents nutrients, like nitrogen, phosphorus, and trace metals, that are more abundant in colder waters below from reaching phytoplankton at the surface.  This process of stratification creates zones of relatively nutrient-poor surface water and these regions within our ocean are expanding with climate change.

One of the things that our research is trying to understand is how these changes – increased temperature and reduced nutrient supply – in some areas of the ocean will influence the kinds of phytoplankton that are present and how do those shifts influence the ecological services that they perform.  In other words, we want to know who the winners and losers will be in a changed and changing ocean and what does that mean for the cycling of nutrients and carbon and for the food web.

From the perspective of phytoplankton, the kind of pollution that is generally the most impactful comes from excessive influx of nutrients, like nitrogen and phosphorus, into the water.  These nutrients are coming from fertilizer runoff from lawns, golf courses, and farms.  They can also come from stormwater runoff and sewage, either from seepage from old infrastructure or from combined sewer overflows (CSOs).  Phytoplankton use nitrogen and phosphorus to grow, but when nutrients are in excess it can lead to rapid and massive overgrowth, or “blooms,” and sometimes these blooms have harmful consequences.

5.  What is a harmful algal bloom?

A harmful algal bloom (HAB) is a rapid proliferation or overgrowth of phytoplankton in marine or freshwater that results in a negative impact such as:  toxin production, light blockage, low oxygen, and drinking water contamination.  Toxin production by some species of freshwater and marine phytoplankton can pose health risks to birds, fish, pets, and humans.  These large blooms of phytoplankton can also cover enough of the surface water that they prevent sunlight from reaching aquatic grasses and macroalgae.

Eventually, these massive overgrowths of phytoplankton die and start to get broken down by bacteria, and this process consumes the oxygen dissolved in the water, leading to ‘dead zones,’ regions of low oxygen (hypoxic) or no oxygen (anoxic) waters that can cause fish kills.  And, in freshwater systems, these proliferations and die-offs of phytoplankton can lead to problems with drinking water, either through clogged filtration infrastructure, toxin contamination, or simply from off-flavors from metabolites produced by the organisms during their growth or decline.

6. How are you involved with the Art Meets Science projects at LDEO?

Lamont graduate students started a Research as Art effort back in 2016 as an opportunity for Lamonters to showcase artwork related to or often derived directly from their research, share their science in a novel way, and build community.   With COVID, the effort hibernated for a couple years.  I helped resurrect the program in 2024, and it’s once again an annual event.

For me, the intersection between art and science has been easy to find. With their diversity of shapes and intricate structures, looking at different kinds of marine phytoplankton under the microscope is like looking at art.  It’s such a great way to make science accessible to lots of different people – people who might otherwise be worried that the science might overwhelm them are given a way into the conversation that feels approachable and disarming.  I think that’s a really valuable tool, especially now.  And it’s something that we use frequently in our own lab group to reach diverse audiences.

About 20 years ago, we developed a program called The Artistic Oceanographer as a means to encourage ocean science literacy through multidisciplinary learning.  The program pairs science and art to engage elementary-age students in learning about different kinds of marine phytoplankton and their strategies for surviving in the ocean.

7. You serve as the chair of the Lamont Ecosystem Impacts & Stewardship Committee (LEISC).  What does LEISC do and what is your vision in shaping this committee?

Let me first say that Lamont is a really unique place.  It’s obviously unique in the caliber and breadth of its contributions to earth science, but it’s also unique in its location.  It’s part of Columbia University, but it’s not in Manhattan.  It’s across the Hudson River and about 15 miles north of Columbia’s Morningside Campus on roughly 200 picturesque and ecologically-diverse acres that link two state parks; these features make the Lamont campus really important for migratory and resident wildlife.  This special geographic nexus, coupled with recognition of our community obligation to be good ecological stewards – to do better - is what led to the formation of LEISC.

The Committee is largely working to guide conversation toward best practices where it can, related to landscaping for wildlife value, supporting bird well-being, and mitigating light pollution, and improve community awareness of ecological and environmental connections and why they are important.

8. This year, the theme for World Migratory Bird Day is "Every Bird Counts – Your Observations Matter!" The theme focuses on the power of community (citizen) science, highlighting how everyday birdwatchers and eBird checklists help scientists track population trends, migration patterns, and conservation needs across global flyways. As part of the Science Meets Art project, Lamont has an art installation of the Atmosphere Flag CCL.  What has LEISC done to support this day’s theme?

Protecting wildlife, specifically resident and migratory birds, is a really important part of climate resilience.  The United Nations stated that biodiversity is “our strongest natural defense against climate change.”  Birds play a vital role in a whole array of different ecological services – processes that make our planet work and remain livable.  They pollinate, they transport seeds, they cycle nutrients, they break down carrion, they control insect populations, and they are environmental health indicators.  And, they do all these things in a variety of shapes, sizes, colors, and often with a beautiful song.

The Lamont campus is a stopover or permanent residence for at least 140 species of birds.  However, all of the buildings on campus were built before bird-safe building design was considered and birds do hit habitat-reflective glass and are killed or injured.  To address this, LEISC has worked with various partners, including the Rockland Audubon Society and several private donors, to treat windows on several of Lamont’s buildings to prevent window collisions.  LEISC has installed two types of window treatments that have been rated effective by the American Bird Conservancy: FeatherFriendly dot decals and Acopian BirdSavers.

Concurrent with this effort, LEISC reports, and encourages community reporting of, dead and injured birds on dBird.org, a US-based citizen science effort and project of the NYC Bird Alliance, to use these submissions to inform problem areas and guide conservation efforts in those hot spots.  By pairing protection efforts with data collection through dBird, LEISC supports the theme for World Migratory Bird Day - "Every Bird Counts – Your Observations Matter!"

9. Anything else you would like to add?

Yes.  Rachel Carson was a scientist, conservationist, and nature writer; her most famous work is Silent Spring.  In this book she writes, “...in nature, nothing exists alone.”  For me, this is the idea that unites my work as a scientist, my interest in art as a tool to convey my science, and my efforts to promote responsible stewardship practices for the land and for wildlife.  Everything on this planet is connected, and always by the unseen - unseen because they are either too fast, too slow, too vast, or too tiny.  When you start to see the unseen, you begin to realize just how incredible our planet is and to appreciate the complexity underpinning its habitability.

10. How can people reach you?

People can reach me by email at shaley@ldeo.columbia.edu.