Sequencing environmental DNA – or eDNA – from the East River in New York City can effectively monitor human diets and local wildlife, as well as the river's fish populations, report Mark Stoeckle and Jesse Ausubel of The Rockefeller University, U.S., in a study publishing April 29, 2026 in the open-access journal PLOS One.
Surveying fish populations in the East River – a rocky estuary channel with fast currents that is contaminated with wastewater discharge – is difficult to accomplish with traditional methods, such as netting or trapping. As an alternative, Stoeckle and Ausubel turned to eDNA – strands of DNA that organisms shed into the water through feces, mucus, skin cells, and carcasses – which can then be detected in the lab. The researchers collected water samples from one spot in the East River weekly for a year. They spiked each sample with a known amount of synthetic DNA, which enabled them to quantify the amount of eDNA from different fish species and other organisms present in the water.
The researchers detected eDNA from humans in the river water, alongside domesticated land animals and non-local fish which are commonly eaten by humans: for example, chicken, turkey and cow eDNA. The levels of eDNA from these animals correlated those of human eDNA, suggesting they could be traced back to wastewater that had contaminated the river. This wastewater analysis might therefore be valuable in revealing the dietary habits of local human residents.
Additionally, the researchers found eDNA from animals presumed to be local wildlife; for example, rats, beavers and racoons. In terms of aquatic life, the eDNA levels effectively reflected expected fish population sizes, and also showed seasonal patterns in line with known fish movements. For example, there was about 10 times more eDNA in the summer than in the winter, when some species move to warmer waters elsewhere. The analysis, however, also showed recent changes in fish populations, with two fish species – skilletfish and feather blenny – becoming much more abundant since 2016, according to a comparison with a previous eDNA survey conducted at the same site.
The researchers conclude that quantifying eDNA is a practical approach to monitoring animal species that could have wide usage in urban estuaries. The study also highlights wastewater eDNA as a useful source of information for tracking the abundance of land animals and human consumption of meat and fish. This approach may aid estuary fish and wildlife management and also opens a window into the human diet.
In your coverage, please use this URL to provide access to the freely available article in PLOS One: https://plos.io/4tRCHK3
Citation: Stoeckle MY, Ausubel JH (2026) Biomonitoring in the Anthropocene: Urban estuary environmental DNA tracks marine fish, terrestrial wildlife, and human diet. PLoS One 21(4): e0332676. https://doi.org/10.1371/journal.pone.0332676
Author countries: U.S.A.
Funding: Source: NOAA Ocean Exploration Title: Collaborating with NOAA to advance marine environmental DNA science. Grant Number: NA23OAR0110593-T1-01.
