World of Sharks

Parasites have a bad rep. We often see them as harmful, exploitative, and just plain icky. But in the shark world, parasites are much more than just irritating hitchhikers. They are ecosystem engineers and important indicators of the health of not just sharks, but the entire ocean. And studies are starting to show some may actually benefit our sharky friends.

Isla met with shark parasitologists Dr Bjoern Schaeffner and Dr Jaime Penadés Suay at Sharks International, Sri Lanka, where they were hosting a workshop on shark parasites. Together, they discuss what parasites we might find in and on sharks, their critical ecological and biological roles, and why on earth we should care about them, before heading to an outdoor dissection in the seaside city of Negombo to explore, hands-on, the world inside of sharks. 

Shownotes: www.saveourseas.com/worldofsharks/podcast

We're diving back into our mailbag to answer more of your burning sharky questions! In this episode we address all sorts of fascinating queries such as how bioluminescence evolved in sharks, which species are capable of breathing while they’re not swimming, and whether sharks are really older than trees. Plus, we take deep dives into several awesome species – great white sharks, grey reef sharks, pocket sharks and of course, James’ favourite, the velvet belly lantern shark. 

Specific question timestamps:

Q1: Are there any shark species that are showing signs of adapting well to climate change? [3.36 – 10.21]

Q2: Has there ever been more observations of any of the two species of Mollisquama (pocket sharks)? [10.31 – 13.20]

Q3: How did bioluminescence in species like the pocket shark evolve? Was it independent, or did their last common ancestor have bioluminescent fluid? [13.40-15.11]

Q4: We rarely hear about white sharks in the vicinity of South America, either ocean, with the exception of seasonal migrations of NA white sharks into the US South Atlantic coast and Caribbean. My question is: why not? [15.22 – 21.49]

Q5: Which shark species can stay still and breathe through buccal pumping? [21.59-28.44]

Q6: Which species of shark and ray are most closely related? [28.54 – 37.50]

Q7: What is the most surprising thing you’ve learnt in your career (when you first started, vs. most recently)? [37.58 – 44.58]

Q8: Shark [bite incidents] often go unreported for various reasons despite the best efforts of educational institutes to accurately record them. What do you think the real number of global [incidents] might be? [45.06-52.14]

Do you have any questions you'd like researched and answered on the pod? Get in touch! You can email isla@saveourseas.com or message us on socials: @saveourseasfoundation.

Art has the power to change perspectives, spark dialogue, and raise awareness of the complex issues facing our ocean. This is exactly why PangeaSeed was established. Since its inception in 2010, PangeaSeed has brought together local artists and their communities to collaborate on large-scale, vibrant public artworks on the walls of their towns and cities, depicting the ocean, her inhabitants, and the challenges she faces, in line with PangeaSeed's mission to bridge art and science. Over the last decade,  over 500 murals have been created in locations across the world. Ahead of their travels to Seychelles, Isla sat down with executive director and director of operations for PangeaSeed, Tre and Akira, to discuss the intersection of art and ocean conservation, the importance of community and connection, and how sharks started an entire movement. 

You can find out more about PangeaSeed here www.pangeaseed.org, or on social media (@pangeaseed and @seawalls_). 

Shownotes: www.saveourseas.com/worldofsharks/podcast

Follow us on socials! We are @saveourseasfoundation across all platforms.

In August 2025, a paper published in the journal Frontiers in Marine Science suggested that ocean acidification could negatively impact a shark's most useful tool: their teeth. We speak with the papers lead author, Max Baum, about this research, and what the findings could mean for the sharks of tomorrow. Plus we take a deep dive into the wonders of shark teeth, and meet a decidedly unbothered tiger shark named Farida.

You can read the paper we discuss in this episode here: Simulated Ocean Acidification Affects Shark Tooth Morphology 

You can also follow Max on Instagram (@maxbaum_insights) and discover more about his work here: www.ocean-insights.org.

Full shownotes: www.saveourseas.com/worldofsharks/podcast.

Find out more about us by following @saveourseasfoundation across all platforms!

Sharks have been around a long, long time (over 450 million years!). But how did they evolve into the extraordinarily diverse and successful group of animals that we have today? On today's episode, we meet palaeontologist and author of The Secret History of Sharks, Professor John Long, to discuss a thrilling story of evolutionary experimentation, fossilised clues, and above all, survival.

The Secret History of Sharks is available now: https://www.quercusbooks.co.uk/titles/john-long-2/the-secret-history-of-sharks/9781529427356/

Shownotes: www.saveourseas.com/worldofsharks/podcast