Area of Research: Oceans
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 2022, 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.
2nd National eDNA workshop videos, slides
The proceedings from the 2nd National Workshop on Marine Enviromental eDNA 11-14 Sept 2022 in southern California have now been posted. Mark Stoeckle presented the opening Plenary.
- Agenda
- eDNA primer
- Training Day: Recording and Slides
- Plenary Day: Recording (Part I and Part II) and Slides (Part 1 begins with Mark Stoeckle’s talk)
- Virtual posters
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 and Oysters
Mark Stoeckle’s summer mentee, high school student Daisy Palaguachi, reports on her work in this poster “Yes, Virginia, There are Oysters in New York Harbor” describing use of aquatic environmental DNA to assess presence of oyster populations. Thanks to Jeanne Garbarino’s RockEDU summer program for introducing PHE to another excellent student.
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.
PHE eDNA student project a finalist in 2022 Genius Olympiad
Samara Davis’s salamander eDNA project is a finalist in 2022 Genius Olympiad. Genius Olympiad is an international high school project competition about environmental issues founded and organized by Terra Science and Education and hosted by the Rochester Institute of Technology. The Olympiad will host projects in five general disciplines with an environmental focus.
Marine Plastics keynote talk
Jesse Ausubel gave the opening talk on “A Cleaner Ocean” to the conference From Research to Action: Responding to Plastic Pollution through Science organized by the Embassy of France Office for Science and Technology in the United States, Global Council for Science and Environment (GCSE), and Long Island University 5-6 April in New York City.