Press Release September 13 2024

Queens College Study Finds That Climate Change is Affecting Fish in Jamaica Bay

 –An established fish community has been partly displaced and the food web has been reshaped–

Flushing, NY, September 30, 2024—Queens College Biology professor John Waldman, an expert on human impacts on fish populations, has co-authored a new study that shows climate change is significantly affecting fish populations in Jamaica Bay—a biologically rich, ecologically important wetland estuary, located mainly in Queens and Brooklyn, that communicates with Lower New York Bay and the Atlantic Ocean. Though it has long been established that the water temperature is rising, this study is the first to break down patterns and drivers of change in the mix of fish species in Jamaica Bay. The study, Decoupled shifts of dominant and rarer fish species as a response to warming and extreme events in a large estuary, was published in the Ecological Society of America journal Ecosphere. It is the largest effort to date to understand how the fish of Jamaica Bay have responded to multiple environmental stressors over the past three decades. Former Queens College biology professor José D. Anadón served as lead author of the study.  

“We believe this study is the most important work to date on fish ecology in Jamaica Bay. It answers important questions about how climate change is affecting our immediate environment and, of course, sheds new light on the larger dynamics of ecologically stressed marine life,” says Queens College President Frank H. Wu. “Every year the world breaks new temperature records. Knowing what we are up against is essential to meeting the challenge.”

For the past thirty years, due to rising temperatures and the resulting migration of fish northward from warming waters, there has been a slow but steady exodus of many established species from Jamaica Bay and an increase in the number of newly arriving warm-water species. This study provides the most precise picture to date of the altered fish community, and reveals moments of heightened change.

To understand the complicated dynamics of ecosystems, with their disparate scales and types of forces as well as the interplay of multiple trends, requires substantial data and analytical tools. The unusually large database compiled by the New York State Department of Environmental Conservation, which monitored over 900,000 fish in the years 1989–2017, was of essential value to this research. That data allowed the team of scientists to detect and describe in exceptional detail how the fish population had changed over time, both in the types of fish present and the overall mix of species. They also were able to distinguish distinct drivers of change—both long-term environmental factors like temperature change, and specific extreme events.

The study found that two extreme events involving spikes in temperature fundamentally changed the overall fish community, affecting both dominant and rare species. In 1999, an abrupt shift in fish ecology was caused by the Atlantic Multidecadal Oscillation phase switch (a natural oscillation of cool and warm surface temperatures that occurs every few decades). The Jamaica Bay community shifted from single-species dominance (silversides) to a pattern of intermittent co-dominance with new warm-water species (such as the Atlantic menhaden).

A second extreme event altered the picture dramatically in 2012. Though 2012 is more often associated with Hurricane Sandy, researchers found that its effects on the fish community were short-lived. By contrast, the marine heat wave of that year was a consequential event with lasting impacts; it exacerbated inhospitable conditions in already warming waters. Such heat waves, which may have increased in frequency and intensity due to climate change, can be attributed to human activity.

The marine heat wave of 2012 accelerated the trend toward replacement of fish species, leading to the abrupt collapse of rare and cold-water species in Jamaica Bay and opening the way to larger numbers of warm-water species. These warm-water species have shorter lifespans and higher turnover rates, reproducing faster than the native community of fish. They also reshape the food web, as they occupy lower positions in the food chain (fewer of them serve as predators).

As Waldman sums up, “Our study shows that the fish community around New York is responsive to the effects of warming. We are experiencing another marine heat wave this year, making 2024 possibly another year of pronounced changes.”

This study originated with a thesis by Olivia Pineiro, then a master’s student at Queens and now a doctoral candidate at the University of Miami. Anadón, who is a specialist in impacts of global change on biodiversity, was assistant professor of biology at Queens College when this research was conducted; he is now at the Pyrenean Institute of Ecology in Zaragoza, Spain. Other coauthors are Albert Ruhi, an aquatic ecologist at the University of California Berkeley, and Jesse Hornstein, a fisheries biologist with the New York State Department of Environmental Conservation.

Like New York, many of the world’s great cities are located in coastal zones, and many are at least partially protected from storms by wetlands. Understanding the environmental changes occurring in such areas has gained urgency with the quickened pace of climate change.