Rockefeller University

Program for the Human Environment

Area of Research: Oceans

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.

New code for analyzing eDNA sequences using DADA2 pipeline

For the past year MIchael Coogan, now a grad student in marine science at the U. of New Hampshire, has helped Mark Stoeckle and PHE with improved software for our eDNA studies. See summary below. A pdf of the R code is available here. If you have questions, please write to Mark.

The goal is to adapt the DADA2 pipeline to Mark Stoeckle’s 12S experiment. Sample sequences will be identified using 12S reference file containing sequences of 262 unique vertebrates found around New York. The starting point is a set of Illumina-sequenced paired-end fastq files that have been split (or demultiplexed) by sample and which have barcodes/adapters already removed. The end product will be a sequence table, analogous to the ubiquitous “OTU table”, which records the number of times sample sequences were observed in each sample. The key difference between the output of DADA2 and standard OTU analyses is that DADA2 infers sample sequences exactly rather than clustering sequences into fuzzy OTUs which hide and complicate biological variation.

Fishing for DNA in the Hudson

In the morning of 3 November Jesse Ausubel summarized the work led by Mark Stoeckle about catching eDNA in the waters of New York City to learn about our local fish species. The site was the beautiful new Little Island in the Hudson River Estuary Park. We post the deck of slides which span from Central Park to the Hudson and East rivers to the Gowanus Canal and Coney Island. New York City enjoys the presence of dozens of fish species, ranging from eels to sturgeon.

Jesse Ausubel to receive 2022 Nierenberg Prize

Jesse Ausubel will be honored with the 2022 Nierenberg Prize for Science in the Public Interest. This award is presented annually by Scripps Institution of Oceanography at UC San Diego and the Nierenberg Family to honor the memory of William A. Nierenberg, an esteemed physicist and national science leader who served Scripps Oceanography as director for two decades. Previous awardees include atmospheric scientist Warren Washington, biochemist and Nobel Prize winner Jennifer Doudna, filmmaker Sir David Attenborough, and primatologist Dame Jane Goodall, among others.

eDNA degradation; 2nd National Workshop

PHE’s guest investigator David Thaler offers some stimulating ideas in a memo about ways of understanding and learning from degradation of aquatic eDNA. The title: How long has each particular species’ eDNA been outside the organism from which it came? Some thoughts on the possibility to obtain more information from eDNA analysis of water samples

Meanwhile, Jesse Ausubel and Mark Stoeckle are involved in the program for the 2nd US National Workshop on eDNA, 12-15 September in Southern California. PHE hosted the 1st US national meeting in 2018.