eDNA with Georgia Nester

eDNA with Georgia Nester | The Deep Sea Podcast | Episode 59

“Exploration is about the place, adventurism is about the person, science is about the question”

Professor Alan Jamieson

In an episode recorded earlier than usual, which is to say not recorded late, and so perhaps recorded right on time?... we are talking about environmental DNA or eDNA.

Thom is headed off to Norfolk Island, north of New Zealand, to characterize the unique life in the region and hopefully not be eaten by sharks. Alan’s been up to secret things, organizing everyone’s lives and, for a change, is recording this episode from the same country as the last one.

In the news, Thom and Alan discuss a recent paper about the extent of ocean exploration, the valuable research it was based on, and the unfortunately defeatist tone. There is a lot left to do, but we have done so much!

Also in the news: Bottom trawling releases not only organic carbon into the ocean but also pyrite, which reacts with oxygen in the water and reduces the oceans’ ability to absorb carbon from the air. An art installation pairs a Sri Lankan artist with JAMSTEC and NuStar Technologies for a collection of steel cubes located 7,000 meters (23,000 feet) below the ocean close to the Marianas Trench. The cubes are housed in a seismic monitoring system designed for registering tectonic plate movements. And finally Al and Thom discuss gene mutation in deep-sea fish and a new paper that gives evidence to an old theory that some deep-sea fish are “ancient survivors,” from dinosaur times, while others are “new immigrants,” post mass extinction.

For this month’s interview, we speak with Dr. Georgia Nester, a colleague of Alan’s from the University of Western Australia, about eDNA (Environmental DNA is any genetic material left behind by organisms in an environment). She talks about how several collection methods, eg.: Niskin bottles, sponges and paper filters, located on the deep-sea lander system, can retrieve different types of eDNA from the deep. Georgia also touches on how diel migrators can really mess with eDNA data, and larvae gave her a surprise when she kept getting hits from very deep-living fish in her surface samples. Georgia even used a water sample to locate surprise eDNA evidence of the Giant Squid in Australian waters, which Al takes as a chance to remind Thom of his Antarctic colossal squid failure.

Alan talks about how valuable he thinks eDNA is, how it can give a great snapshot of what can’t be seen on the footage or in the submersible, and how it might be able to narrow down species that are difficult to catch, like Bassozetus cusk eels.

Hold onto your buoyant elbow glands because we’ve got a great episode here!

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Reference list News

1. Only 0.001% of the deep sea has been seen in 70 years.
2. Bottom Trawling stops ocean absorbing carbon dioxide
3. Art Installation near the Marianas Trench
4. Deep-Sea Fish have independently evolved the same Gene Mutation for pressure

Interview

Nester, G. M., Suter, L., Kitchener, J. A., Bunce, M., Polanowski, A. M., Wasserman, J., & Deagle, B. (2024). Long-distance Southern Ocean environmental DNA (eDNA) transect provides insights into spatial marine biota and invasion pathways for non-native species. Science of the Total Environment, 951, 175657.

Takahashi, M., Saccò, M., Kestel, J. H., Nester, G., Campbell, M. A., Van Der Heyde, M., ... & Allentoft, M. E. (2023). Aquatic environmental DNA: A review of the macro-organismal biomonitoring revolution. Science of the Total Environment, 873, 162322.

Credits

Theme: Hadal Zone Express by Märvel

Logo image: Microsoft CoPilot

Song of the month: Crazy Train by Ozzy Osbourne, performed by William Jamieson