Rockefeller University

Program for the Human Environment

Area of Research: DNA Barcoding

DNA of New York City’s East River

Mark Y. Stoeckle and Jesse H. Ausubel

Animals shed environmental DNA (eDNA) into the environment. Sources include cells sloughed from body surfaces, body wastes, and tissue remnants following predation, death, or injury.  eDNA is a bit like dandruff.  DNA of course consists of long strands of four chemical compounds: cytosine (C), adenine (A), guanine (G), and thymine (T). Researchers use strands of about 100 “letters” from variable parts of the genome, like a long telephone number, to identify the species of animal from which the DNA comes. Acidity, heat, and light can speed eDNA degradation, and bacteria eat eDNA. A rule of thumb is that eDNA sufficient for reliable identification lasts about 24 hours and thus gives a good current portrait of life in a water body.

As seen in these 5 slides, the PHE’s Mark Stoeckle regularly collects a half liter of water from the East River adjacent to the Rockefeller campus (slide 1) with a bucket on a string, filters the water, extracts the DNA from the sediment on the filter using special chemicals called primers to grab only the DNA that came from vertebrates, sequences these pieces of eDNA, and matches the sequences against genetic libraries. The number of copies for each species corresponds well to the recent abundance of that animal in the East River.

Our vertebrate eDNA studies show that that the East River abounds in fishes (slide 2), with tautog most common but also herring, bass, and eel.  The presence of water from sewage treatment plants and rains that wash city streets also brings DNA of urban wildlife into the East River.  A cup of water from the East River reports the abundance of rats, pigeons, dogs, and cats (slide 3).  It also reports the presence in the River or nearby of additional wildlife ranging from deer and beaver to seal and dolphin (slide 4).  Finally, the eDNA in the East River neatly tracks the diet of humans of New York (slide 5).  The fractions of aquatic eDNA of commonly consumed meats such as chicken and cow match nicely with national data on meat consumption.  An exception is sea bass (branzino), widely served in New York City restaurants and thus common in East River water samples but a tiny proportion of the national fish diet.

eDNA revolutionizes the ability for people to know, affordably, what animals live in or use the waters near them. eDNA will be a routine component of fish stock assessment, detection of invasive species, and monitoring effects of coastal storms and climate change.  Genomics enables a cup of water to tell the natural history of the East River.

New paper on eDNA as way to define marine regions

PLOS One publishes our new paper demonstrating the use of eDNA to define marine biogeography.  This graphic summarizes key findings of the paper.  The paper builds on our earlier work proving that loose DNA in seawater reveals both diversity AND abundance of marine life, in particular, fishes.  Full title and abstract are below.

A potential tool for marine biogeography: eDNA-dominant fish species differ among coastal habitats and by season concordant with gear-based assessments Mark Y. Stoeckle , Jesse H. Ausubel, Greg Hinks, Stacy M. VanMorter Published: November 11, 2024 https://doi.org/10.1371/journal.pone.0313170

Abstract Effective ocean management asks for up-to-date knowledge of marine biogeography. Here we compare eDNA and gear-based assessments of marine fish populations using an approach that focuses on the commonest species. The protocol takes advantage of the “hollow curve” of species abundance distributions, with a minority of species comprising the great majority of individuals or biomass. We analyzed new and published teleost eDNA metabarcoding surveys from three neighboring northwest Atlantic coastal locations representing sandy, rocky, or estuary habitat. Fish eDNA followed a hollow curve species abundance distribution at each location—the 10 commonest taxa accounted for more than 90% of eDNA copies. Top ten taxa were designated eDNA-dominant species (eDDS) and categorized as habitat-associated (top 10 in one study) or as shared. eDDS by category were similarly abundant in concurrent bottom trawl and seine surveys. eDDS habitat category profiles correctly classified most (94%-100%) individual eDNA and capture measurements within surveys and recognized estuarine sites in other regional eDNA and seine studies. Using a category metric like that for habitats, eDDS demonstrated strong seasonal turnover concordant with trawl catch weights. eDNA seasonal profiles applied to historical trawl and seine records highlighted known long-term trends in mid-Atlantic fish populations. This study provides evidence that eDNA-abundant fish species differ among coastal habitats and by season consistent with gear-based assessments. Grouping abundant species by category facilitated comparisons among habitats and integration with established surveys. eDNA metabarcoding of dominant fish species potentially offers a useful tool for marine biogeography and ocean monitoring.

Jesse & Mark NOAA ‘Omics Webinar on eDNA-dominant fish species

NOAA has posted the video of their ‘Omics Seminar Series: eDNA-Dominant Marine Fish Species Characterize Coastal Habitats presented on 28 February, 2024 by Mark Stoeckle and Jesse Ausubel. The 1-hour seminar is full of new results and ideas about using eDNA data to characterize marine regions and features Mark’s excellent graphics.

Title: eDNA-Dominant Marine Fish Species Characterize Coastal Habitats: an eDNA-Based Classifier Approach to Aid Marine Biogeography and Ocean Monitoring by Mark Stoeckle & Jesse Ausubel

Abstract: A small minority of species typically account for the great majority of individuals or biomass. Here we characterize marine coastal habitats based on abundance of marine fish environmental DNA. We designate the ten most eDNA-abundant fish species in each habitat as eDNA-dominant species. eDNA-dominant species are similar within but differ among habitats and seasons and accord with abundance by traditional survey methods. “Classifiers” based on eDNA-dominant fish species could help map marine fish habitats and monitor changing oceans. Advantages include relatively low sampling requirements, a single technology applicable to diverse habitats, and ease of application to multiple datasets.

eDNA of Newtown Creek, industrial waterway separating Queens & Brooklyn

RockEDU summer students Priyam Shah and Michael Epelman, who just completed high school, teamed with mentor extraordinaire Mark Stoeckle to study the fishes of an NYC Superfund Site, Newtown Creek.  Their excellent poster shows that eDNA detected a surprising diversity of fish in Newtown Creek, despite ongoing pollution and sewage overflow. The number and relative abundance of fish species differed among sites consistent with species habitat preference and pollution tolerance. Our data support eDNA as a cost-effective, non-destructive method for monitoring fish populations and assessing habitat restoration efforts in Newtown Creek and other Superfund sites

eDNA biodiversity survey of Charles River & Boston Harbor

For a 50th Harvard College Reunion Seminar on EO Wilson’s proposal to conserve half Earth, Jesse Ausubel and Mark Stoeckle, assisted by Elizabeth Munnell, conducted a survey of vertebrates in three locations in the Charles River and two in Boston Harbor.  The 14 slides on The Charles River and Boston Harbor Then and Now tell a story of remarkable ecological recovery.

New software for visualizing the whole animal kingdom

Swiss bioinformatics wizard Wandrille Duchemin and PHE Guest Investigator David Thaler publish PyKleeBarcode: Enabling representation of the whole animal kingdom in information space in PLoS One. The computational advances in the paper open the way to calculating DNA-relatedness of all animal species, as the figure below for mammals suggests.

Fig 2.  A. View of the structure matrix of the mammalian dataset and taxonomic structure of Mammalia. B. Phylogenetic tree structure of the taxonomic groups retrieved from NCBI taxonomy.

The paper builds on the pioneering work done earlier in the PHE by Larry Sirovich and Mark Stoeckle:

L Sirovich, MY Stoeckle, Y Zhang. A scalable method for analysis and display of DNA sequences. PLoS ONE 4 (10): e7051, 2009

L Sirovich, MY Stoeckle, Y Zhang. Structural analysis of biodiversity. PLoS ONE 5 (2): e9266, 2010

MY Stoeckle, C Coffran. TreeParser-Aided Klee Diagrams Display Taxonomic Clusters in DNA Barcode and Nuclear Gene Datasets . Nature Scientific Reports 3 (2635): 2013

Our paper on eDNA as bioassay of Anthropocene published

The new journal based in China, The Innovation, has published the Thaler-Ausubel-Stoeckle paper on Human and domesticated animal environmental DNA as bioassays of the Anthropocene in their “Out of the Box” category, where we like to be. We also post the pdf.

We thank Song Sun and Ke Chen for editorial assistance.

Summary: Human and domesticated animal sequences, commonly detected in environmental DNA (eDNA) metabarcoding studies, are routinely excluded from analysis. Here we suggest that reporting human and domesticated animal eDNA results might open new lines of investigation. For example, the relative abundance of human and domesticated animal eDNA as compared to that of wild vertebrate species might provide an index of human impact on local biota. Such an index could be applied to sites ranging from urban harbors to remote villages, and possibly to analyze historical samples. Various potential sources of contamination complicate the picture, but it should be possible to develop procedures that minimize risk of DNA introduction during collection and processing. Our near-term recommendation is to encourage inclusion of human and domesticated animal data in eDNA publications as an incentive for discovery, to lift quality controls, and to collectively contribute to new vistas that eDNA science might open.

Our article on incorporating a known amount of non-fish DNA to allow better quantification of the fish DNA present in a seawater sample appears in the journal Environmental DNA.

Open Access

12S gene metabarcoding with DNA standard quantifies marine bony fish environmental DNA, identifies threshold for reproducible detection, and overcomes distortion due to amplification of non-fish DNA.  Mark Y. Stoeckle, Jesse H. Ausubel, Michael Coogan, first published: 08 December 2022, https://doi.org/10.1002/edn3.376

While our paper focuses on fish, we believe the approach of “spiking” samples collected in nature with known amounts of DNA from a species that would not be present in the sample (such as ostrich) offers great promise for increasing the value of a wide range of aquatic DNA studies. The exhibit below shares some of the main points from the paper.