Ocean Science Radio

Guest: Oliver Gunasekara, CEO & Co-Founder, Impossible Metals

Website: impossiblemetals.com

Eureka Collection System animation: https://impossiblemetals.com/blog/next-generation-eureka-collection-system-animation-now-available/

Context & Further Reading:

ISA (International Seabed Authority): isa.int

DISCOL experiment — long-term seafloor disturbance study: https://www.discol.de/index.html

IEA Critical Minerals Report (recycling projections): https://www.iea.org/reports/global-critical-minerals-outlook-2025

Our previous episode: Trump Administration Ocean Policy Forum with Dr. Andrew Thaler, Dr. Diva Amon, and Angelo Villagomez

Key Terms:

Polymetallic nodules: Mineral-rich concretions found on the deep seafloor, taking millions of years to form

UNCLOS: United Nations Convention on the Law of the Sea

Common Heritage of Mankind: Legal principle that certain global resources belong to all of humanity

ISA: International Seabed Authority — the UN body governing deep seabed mining in international waters

AUV: Autonomous Underwater Vehicle

BGR: German Federal Institute for Geosciences and Natural Resources (Bundesanstalt für Geowissenschaften und Rohstoffe)

Episode Description

Making babies is expensive. For pretty much every species on the planet, reproduction is supposed to be the ultimate metabolic investment—a massive energy drain that can make organisms vulnerable to stress, predators, and environmental change. Except there's a small shark walking around the Great Barrier Reef that apparently didn't get the memo.

In this episode of our Ocean Lovin' series, we explore groundbreaking research from James Cook University that's forcing scientists to completely rethink what they know about the costs of reproduction. Epaulette sharks—those amazing little "walking sharks" that can literally stroll across reef flats on their fins—can produce complex egg cases with developing embryos inside without any measurable increase in energy use. Zero. Zilch. Nada. It's like building a house without buying any extra lumber.

Join hosts Andrew Kornblatt and Dr. Frances Farabaugh, along with returning guest co-host Dr. Skylar Bayer, as we dive into this surprising discovery with Professor Jodie Rummer from James Cook University. We'll explore how her team measured something no one had measured before—the metabolic cost of egg-laying in sharks—and what they found challenges fundamental assumptions about reproduction in the ocean.

We'll learn about the "pay as you go" hypothesis, discover why a tiny organ might be working overtime without changing the whole shark's energy budget, and explore what this means for sharks facing climate change. From the controlled environment of the lab to wild populations scattered across the Great Barrier Reef, this research reveals that evolution has equipped some species with surprising tools for survival that we're only beginning to understand.

Content Advisory: This Ocean Lovin' episode deals with mature subjects related to marine reproduction. Please listen to the full episode before sharing with younger audiences.

Featured Guest

Professor Jodie Rummer

Professor of Marine Biology, James Cook University, Australia

Conservation physiologist specializing in sharks and coral reef fishes

Leads shark physiology research team at JCU's Marine and Aquaculture Research Facility

Maintains a breeding colony of epaulette sharks for multi-generational research

Expert in how marine organisms cope with climate change stressors (temperature, ocean acidification, low oxygen)

Key Topics Covered

The Discovery

First direct measurement of metabolic costs of egg-laying in sharks

Completely flat metabolic rate across reproductive cycle—no energy spike

37 trials, nearly 200 eggs, almost 100 reproductive cycles

The Science

How scientists measure metabolic rate through oxygen uptake

The "pay as you go" hypothesis: income breeding vs. stored energy

The nidamental gland paradox: tiny organ, massive output

Blood chemistry and hormone stability during reproduction

Epaulette Shark Biology

One of nine "walking shark" species with modified pectoral fins

Can survive zero oxygen conditions for several hours

Endemic to Great Barrier Reef, living in extreme reef flat environments

Produce two eggs every ~19 days during breeding season

Four-month embryonic development period

Climate Change Implications

Challenging the assumption that "reproduction will be the first thing to go" under stress

Potential resilience in warming oceans—but limits unknown

Effects of elevated temperatures on embryo development and hatchling size

Importance of protecting critical habitats where adaptations can function

Future Research Directions

Testing upper limits of reproductive efficiency under warming

Local adaptation across Great Barrier Reef populations

Immune function in mothers and hatchlings under stress

Applications to other shark species and conservation strategies

Featured Research

Primary Study: Wheeler, C.R., Awruch, C.A., Mandelman, J.W., & Rummer, J.L. (2025). "Assessing the metabolic and physiological costs of oviparity in the epaulette shark (Hemiscyllium ocellatum)." Biology Open, 14(11). DOI: 10.1242/bio.062076

Lead Author: Dr. Carolyn Wheeler (recent JCU PhD graduate)

Resources & Links

Research Institution:

James Cook University Marine and Aquaculture Research Facility, Townsville, Australia

JCU Marine Biology

Conservation Organizations:

Great Barrier Reef Marine Park Authority

IUCN Shark Specialist Group

Press Coverage:

JCU News Release

ScienceDaily Article

Episode Credits

Hosts:

Andrew Kornblatt - Climate and Ocean Communications Specialist, Producer

Dr. Frances Farabaugh - Shark Ecologist, Aquanaut

Guest Co-Host:

Dr. Skylar Bayer - Marine Ecologist (Shellfish Population Dynamics, Fertilization Ecology, Science Communication)

Featured Guest:

Professor Jodie Rummer - James Cook University

90% of seafood consumed on the Oregon coast is imported, while most Oregon-caught seafood gets exported. This week, we explore how that's changing.

We talk with Suzie O'Neill, Kaitlyn Rich, and Jon Bonkoski from Ecotrust, who just launched "Tending the Tides," a podcast about mariculture on the Oregon coast. Learn how oyster farmers became climate sentinels in 2007 when ocean acidification killed their larvae. Discover urchin divers using rock climbing techniques underwater in 50 pounds of lead, and how their catch feeds innovative closed-loop aquaculture systems growing seaweed and sea cucumbers.

From selective breeding programs creating climate-resilient oysters to kelp forests buffering acidification, this episode reveals how Oregon is building regenerative ocean farming that honors Indigenous stewardship, avoids parachute science, and redefines what sustainable food systems look like.

Featuring the Oregon Coastal Mariculture Collaborative's community-led approach to expanding "unfed aquaculture"—oysters and seaweed that grow without any inputs beyond what the ocean provides.

What happens when an entire industry rushes forward before science can catch up? In this episode of Ocean Science Radio, we sit down with Dr. Andrew Thaler, deep-sea ecologist and CEO of Blackbeard Biologic, to explore his groundbreaking report for the Convention on Migratory Species that reveals exactly how much we don't know about deep-sea mining's impacts on whales, dolphins, sharks, turtles, and other highly migratory species.

While most deep-sea mining research has focused on the immediate destruction of seafloor ecosystems, Andrew's report exposes a more troubling reality: we have massive knowledge gaps about how mining operations—with their noise, sediment plumes, and habitat disruption—might affect species that travel thousands of miles across interconnected ocean basins. From sea turtles navigating by magnetic fields to whales relying on acoustic communication, these far-reaching impacts remain largely unstudied even as the industry accelerates toward commercial production.

The conversation takes a timely turn as we discuss the Bureau of Ocean Energy Management's controversial Request for Information for mining in U.S. waters off the Commonwealth of the Northern Mariana Islands. Andrew breaks down why this represents a significant shift from international deep-sea mining debates, and what it means that communities near the Mariana Trench—with only a 30-day comment period and no guaranteed revenue sharing—are being asked to accept an industry that science hasn't fully evaluated.

As the Trump administration pushes to fast-track deep-sea mining for critical minerals while international bodies like the CMS urge precaution, this episode asks the essential question: what's at stake when we mine what we haven't studied? Join us for a conversation that bridges cutting-edge marine science, environmental justice, and the real-world policy decisions happening right now in the deep ocean.

After nearly two decades of negotiations, the world has finally agreed on a framework to protect the high seas - that vast expanse of ocean beyond any nation's control that covers nearly half our planet's surface. On January 17th, 2026, the BBNJ Agreement (Biodiversity Beyond National Jurisdiction), commonly known as the High Seas Treaty, officially enters into force, becoming international law.
Join us as we explore this historic moment with two experts at the heart of the effort. Jeremy Raguain, who works with the Alliance of Small Island States, shares insights on Africa's leadership in the negotiations and what meaningful capacity building looks like for developing nations. Rebecca Hubbard, Director of the High Seas Alliance, takes us through the coalition-building journey from 2002 to today, explaining the treaty's four pillars: marine protected areas, equitable benefit-sharing from marine genetic resources, environmental impact assessments, and capacity building.
This isn't just another international agreement - it's the missing piece that could finally allow us to protect 30% of the ocean by 2030, ensure that benefits from ocean resources flow equitably to all nations, and shift away from "parachute science" toward true partnerships. From small island nations reclaiming their identity as "big ocean states" to the complex work of enforcing protections in the world's most remote waters, this episode explores what becomes possible when the world comes together to protect what belongs to us all.
Whether you live on a coast or in a landlocked country, half the oxygen you breathe comes from the ocean. Its health is humanity's health. Discover why this treaty matters for everyone, and what you can do to support its implementation.
Featured Guests:
Jeremy Raguain, AOSIS Fellowship Director & Ocean Governance Specialist
Rebecca Hubbard, Director of the High Seas Alliance
Episode Length: 35-40 minutes